Corals are popular as souvenirs, for home decor and in costume jewelry, yet corals are living animals that eat, grow, and reproduce. It takes corals decades or longer to create reef structures, so leave corals and other marine life on the reef.
Corals have long been popular as souvenirs, for home decor, and in jewelry, but many consumers are unaware that these beautiful structures are made by living creatures. Fewer still realize that corals are dying off at alarming rates around the world.
Coral reefs are some of the most biologically rich and valuable ecosystems on Earth, but they are threatened by an increasing array of impacts—primarily from global climate change, unsustainable fishing, and pollution. Strong consumer demand for coral, heightened over the holiday season, is another factor that is contributing to the decline of coral reefs. Each year, the U.S. imports tons of dead coral for home decorations and curios. Most of these corals are shallow-water species.
The U.S. is also the world's largest documented consumer of Corallium, red and pink corals often used to create jewelry. Finished pieces of jewelry and art crafted from this type of coral can fetch anywhere between $20 and $20,000 in the marketplace. Continued consumer demand is contributing to the decline of these delicate corals around the world.
Commercial harvesting to satisfy the demand for coral jewelry has reduced colony size, density, and age structure of Corallium over time. Harvesting is also lowering the reproduction capability of this species and is decreasing its genetic diversity. Research indicates that removal of red and pink corals for the global jewelry and art trade is also leading to smaller and smaller Corallium in the wild.
Corals grow very slowly, are extremely long-lived, and take years to reach maturity. It takes corals decades or longer to create reef structures. Once coral is harvested—especially when it's extracted at a young age—surrounding coral beds often do not recover. That's why it's best to leave corals and other marine life on the reef.
Remember: corals are already a gift. Don't give them as presents.
As palm oil production expands from Southeast Asia into tropical regions of the Americas and Africa, vulnerable forests and species on four continents now face increased risk of loss.
The largest areas of vulnerable forest are in Africa and South America, where more than 30 percent of forests within land suitable for oil palm plantations remain unprotected, according to a Duke University study. Rates of recent deforestation have been highest in Southeast Asia and South America, particularly Indonesia, Ecuador and Peru, where more than half of all oil palms are grown on land cleared since 1989.
Palm oil is now the world’s most widely traded vegetable oil, according to the Food and Agriculture Organization of the United Nations. The oil, which is harvested from oil palms, and its derivatives are common ingredients in many processed foods and personal care products. As global demand grows, large swaths of tropical forest are being converted into oil palm plantations in 43 countries.
Almost all oil palm is grown in places that once were tropical forests, forests containing high concentrations of different mammal and bird species at risk of extinction or extirpation. Clearing these forests threatens biodiversity and increases greenhouse gas emissions. By identifying where the greatest extent of palm oil-driven deforestation has recently occurred, and modeling where future expansion is most likely, scientists are hoping to guide efforts to reduce these adverse impacts.
While the Amazon and Indonesia have many species of globally threatened mammals and birds, other areas such as the Congo Basin and the coastal forests of Colombia are home to species with small ranges that make them especially vulnerable to habitat loss despite not being classified as threatened or endangered. This also needs to be considered in conservation planning.
The palm oil industry has a legacy of deforestation, but consumer pressure is pushing companies toward deforestation-free sources of palm oil. Government regulations and voluntary market interventions must reshape oil palm plantation expansion in ways that protect biodiversity-rich ecosystems and prevent deforestation.
You can send a clear message to the palm oil industry by reducing or eliminating your purchases of products containing palm oil.
Greenwashing is hiding harmful activities behind the guise of environmentalism and conservation. It's a tactic many corporations and organizations use to manipulate and deceive the public.
A clean, safe and healthy environment is important, and everyone wants to see it protected. With this goal, many people donate millions of dollars each year to organizations that say they are working to protect the environment and wildlife. Many people also buy products that they believe to be animal and environmentally friendly. But how much do we really know about these organizations, companies and products? For example, do their campaigns demand a ban on toxic chemicals or take the bureaucratic route and call for more testing? Are they concerned about protecting animals as well as people, or do they at least ensure that their activities do not harm animals?
Many generous contributors are shocked to learn that some "environmental" and "conservation" groups use people's donations to support activities that are extremely harmful to the earth and animals and accomplish little or nothing to protect the environment. Some organizations support and even promote the poisoning of animals to test pesticides and other chemicals already known to be toxic. In fact, several well-known environmental groups are directly responsible for the creation of what have become the most massive animal-testing programs in history.
For example, despite killing hundreds of thousands of animals in cruel chemical toxicity tests, the EPA has not banned a single toxic industrial chemical in more than 10 years using its authority under the Toxic Substances Control Act. The chemical industry has long approved of the EPA's near-exclusive reliance on animal tests because their results are easily manipulated. In addition, required testing means that a company's products are safe from regulation for years while the products are tested and retested on animals. And, after decades of practice, industry representatives have perfected the art of arguing both sides of the animal-testing issue.
Here's how they do it: If a chemical is shown to cause cancer or other harmful effects in animals, industry representatives claim that the results aren't applicable to humans. At the same time, company officials happily display the results of EPA-required studies that suggest that their chemicals are not harmful. In these cases, companies laud the predictability of animal-testing and claim that their products are safe for humans. This is exactly what happened with cigarettes for more than 20 years, as industry scientists claimed that tobacco was safe for humans because animal tests, many of which involved cutting holes in the throats of dogs and forcing them to inhale cigarette smoke, did not cause cancer in animals.
The EPA's addiction to animal testing is so pervasive that even when evidence from human population studies implicates a chemical, the results are ignored by the EPA for the sake of conducting more and more animal studies. For years, population studies have shown that arsenic in drinking water causes cancer in humans. Yet the EPA dragged its feet for more than 20 years while thousands of animals were killed in tests that attempted to reproduce the effects already seen in humans.
The matter is made worse by the fact that the EPA refuses to subject animal-based test methods to the same level of scientific validation to determine their reliability and relevance to humans that all non-animal test methods must meet before they are accepted and used. The results of nonvalidated animal tests are scientifically useless as a basis upon which to regulate dangerous chemicals. So, the EPA's animal-testing programs do not protect either people or the environment, despite causing enormous animal suffering. Yet some environmental groups continue to call for ever-more animal-testing and defend every animal test, no matter how cruel or irrelevant.
Many companies and organizations spend more time and money claiming to be “green” through advertising and marketing than actually implementing business practices that minimize environmental impact. Research products and companies before making purchases. If you are a member of, or donate money to environmental or conservation groups, be sure to inquire that your donations are not being used to support greenwashing activities that harm animals and the environment.
There were almost 100,000 tigers roaming the wilds of the planet in the early 1900's. The drastic fall in the population of this magnificent beast to just a few thousands within the span of a century tells a lot about human callousness and cruelty towards wildlife.
Until a couple of decades ago, the tiger was killed purely for sport, especially in India. The times of the maharajahs abound with folklore of how these unfortunate animals were hunted down and showcased in village squares, courtyards and drawing rooms of the wealthy. But with the advent of wildlife reserves and stricter curbs on hunting, the downslide in tiger numbers was somewhat arrested. But the problems for the animal did not end there.
India has nearly two-thirds of the current world tiger population of around 3,890. Competing with that is the human population. At 1.25 billion, and with a growth-rate that shows no signs of abating, India's population is just 10 percent less than China's. But India's populace live in an area that is only one-third of its larger neighbor. A growing population translates into demand for more food and more agricultural space. Thus, encroachment of tiger reserves is an obvious fallout.
Towards the eastern part of the country, changes in climate are causing sea levels of the Bay of Bengal to rise, submerging the Sundarban jungles and its precious mangrove forests. These forests are home to one of the most magnificent beasts in the world, the Royal Bengal tiger. Apart from the threat of a rising sea, the Sundarbans are also witnessing increasing numbers of people, desperately searching for farming land. The tiger is cornered and has nowhere to go. The Sundarban forests of Bengal has been its natural habitat for thousands of years, long before man came.
The tiger population of Indonesia stood at only 371 in 2016. Most are concentrated in the island state of Sumatra. The Sumatran tiger is an endangered species and is the smallest of all tiger species. Ignition of wild forest fires, deforestation by an avaricious palm oil and timber industry, are constant threats to this animal. As a result, they have been squeezed into small pockets of dense hill forests of the island.
Among the most critically endangered species of all animals is the South China tiger. Most alarming, there have been no sightings of the animal in the past two decades – leading experts to believe that it may have become extinct.
The underlying story of the tiger in countries with huge population density is the same, be it India, Bangladesh, Nepal , Malaysia or Indonesia. Hunting land for the animals is shrinking in the face of increasing demand for industry and agriculture, and they are getting much less to eat than before. Domestic animals like cattle, dogs, and, in rare instances, even humans, have become the new food for the big cats. Villagers in search of wood (used as fuel for cooking) often fall prey to tigers. Ironically, the tigers now become the encroachers and end up being killed or hunted down by villagers in the name of self-defense.
Nowhere on earth can the population-land mismatch be more glaring than in Indonesia. The archipelago has a population as large as the United States but a land area just one-tenth the size, broken up into a few thousand islands. Virtually all of Indonesia's low-lying forests have been cleared for cultivation of its staple food, rice. Just imagine where all of this leaves the Indonesian tiger.
While the report card for tiger species safety indicates the lowest levels of threat for the Siberian tiger, the biggest of all wild cats numbering around 400 and having the largest habitat of all, the same cannot be said of the South East Asian species (Indonesia, Malaysia, Laos, Cambodia, Vietnam and Thailand). Urgent action needs to be taken before the crushing human density in these regions squeeze the tiger into extinction.
Add to the threat for tigers is widespread poaching. Tiger skins and other vital organs are in great demand in the underground black-market trade for wildlife exotica, especially in Thailand and China. Forest and wildlife departments are too understaffed or corrupt to keep poachers at bay. There's a lack of training, motivation and compensation for risk among forest personnel. Firearms, communications equipment, and vehicles for use by forest protection enforcement are either inadequate or antiquated.
There is hope. Thanks to the combined efforts of organizations and governments that have woken up to the importance of preserving this wonderful animal, the population of tigers has quite astonishingly shown a turn-around for the first time in over a century. There's been an impressive 22 percent rise in numbers in the last 6 years.
The figures compiled by the International Union for Conservation of Nature and Natural Resources (IUCN) show increases in tiger populations in India, Russia (home of the great Siberian tiger), Nepal and Bhutan. Improved protection measures, stricter laws concerning the safety of the animals, and enhanced conservation and breeding techniques adopted and put into practice by authorities, have given tiger enthusiasts reasons to cheer after a very long struggle.
Three quarters of the world’s threatened species are imperiled because people are converting their habitat into agricultural lands and overharvesting their populations. 72 percent of species are imperiled by overexploitation (the harvesting of species from the wild at rates that cannot be compensated for by reproduction or regrowth), while 62 percent of species are imperiled by agricultural activity (the production of food, fodder, fiber and fuel crops; livestock farming; aquaculture; and the cultivation of trees). In comparison, 19 percent are considered threatened by climate change.
There are 5,407 species threatened by agriculture alone, according to the University of Queensland, Wildlife Conservation Society (WCS) and the International Union for Conservation of Nature (IUCN).
Illegal hunting is decimating populations of all rhinoceros and elephant species, western gorilla and Chinese pangolin. Other threats are affecting substantially fewer species, for example hooded seals being threatened by climate change. Climate change is ranked 7th among 11 threats.
Addressing overharvesting and agricultural activities are key to turning around the biodiversity extinction crisis. This must be at the forefront of the conservation agenda. Government and society must focus on proposing and funding actions that deal with the biggest current threats to biodiversity.
History has taught us that minimizing impacts from overharvesting and agriculture requires a variety of conservation actions, but these can be achieved. Actions such as well managed protected areas, enforcement of hunting regulations, and managing agricultural systems in ways that allow threatened species to persist within them, all have a major role to play in reducing the biodiversity crisis. These activities need to be well funded and prioritized in areas that will reduce threat, according to scientists.
While overharvesting and agricultural activities are currently the predominant threats to species, this may change in the coming decades. Reducing immediate impacts is essential to tackling the biodiversity crisis, but climate change could become an increasingly dominant threat for species.
Thankfully, those actions that best reduce current threats such as unsustainable use, habitat destruction, and invasive species are also the best solutions in responding to the challenges of rapid climate change.
Since life began on Earth, countless creatures have come and gone, rendered extinct by naturally changing physical and biological conditions. Since extinction is part of the natural order, and if many other species remain, some people ask: “Why save endangered species? Why should we spend money and effort to conserve them? How do we benefit?”
Congress answered these questions in the preamble to the Endangered Species Act of 1973, recognizing that endangered and threatened species of wildlife and plants “are of esthetic, ecological, educational, historical, recreational, and scientific value to the Nation and its people.” In this statement, Congress summarized convincing arguments made by scientists, conservationists, and others who are concerned by the disappearance of unique creatures. Congress further stated its intent that the Act should conserve the ecosystems upon which endangered and threatened species depend.
Although extinctions occur naturally, scientific evidence strongly indicates that the current rate of extinction is much higher than the natural or background rate of the past. The main force driving this higher rate of loss is habitat loss. Over-exploitation of wildlife for commercial purposes, the introduction of harmful exotic (nonnative) organisms, environmental pollution, and the spread of diseases also pose serious threats to our world’s biological heritage.
Conservation actions carried out in the United States under the Endangered Species Act have been successful in preventing extinction for 99 percent of the species that are listed as endangered or threatened. However, species loss on a global scale continues to increase due to the environmental effects of human activities.
Biologists estimate that since the Pilgrims landed at Plymouth Rock in 1620, more than 500 species, subspecies, and varieties of our nation’s plants and animals have become extinct. The situation in earth’s most biologically rich ecosystems is even worse. Tropical rainforests around the world, which may contain up to one half of all living species, are losing millions of acres every year. Uncounted species are lost as these habitats are destroyed. In short, there is nothing natural about today’s rate of extinction.
BENEFITS OF DIVERSITY
How many species of plants and animals are there? Although scientists have classified approximately 1.7 million organisms, they recognize that the overwhelming majority have not yet been cataloged. Between 10 and 50 million species may inhabit our planet. None of these creatures exists in a vacuum. All living things are part of a complex, often delicately balanced network called the biosphere. The earth’s biosphere, in turn, is composed of countless ecosystems, which include plants and animals and their physical environments. No one knows how the extinction of organisms will affect the other members of its ecosystem, but the removal of a single species can set off a chain reaction affecting many others. This is especially true for “keystone” species, whose loss can transform or undermine the ecological processes or fundamentally change the species composition of the wildlife community.
CONTRIBUTIONS TO MEDICINE
One of the many tangible benefits of biological diversity has been its contributions to the field of medicine. Each living thing contains a unique reservoir of genetic material that has evolved over eons. This material cannot be retrieved or duplicated if lost. So far, scientists have investigated only a small fraction of the world’s species and have just begun to unravel their chemical secrets to find possible human health benefits to mankind.
No matter how small or obscure a species, it could one day be of direct importance to us all. It was “only” a fungus that gave us penicillin, and certain plants have yielded substances used in drugs to treat heart disease, cancer and a variety of other illnesses. More than a quarter of all prescriptions written annually in the United States contain chemicals discovered in plants. If these organisms had been destroyed before their unique chemistries were known, their secrets would have died with them.
A few hundred wild species have stocked our pharmacies with antibiotics, anti-cancer agents, pain killers and blood thinners. The biochemistry of unexamined species is an unfathomed reservoir of new and potentially more effective substances. The reason is found in the principles of evolutionary biology. Caught in an endless “arms race” with other forms of life, these species have devised myriad ways to combat microbes and cancer-causing runaway cells. Plants can make strange molecules that may never occur to a chemist. For example, the anti-cancer compound taxol, originally extracted from the bark of the Pacific yew tree, is “too fiendishly complex” a chemical structure for researchers to have invented on their own, said a scientist with the U.S. National Cancer Institute. Taxol has become the standard treatment for advanced cases of ovarian cancer, which strikes thousands of women every year. But until the discovery of taxol’s effectiveness, the Pacific yew was considered a weed tree of no value and was routinely destroyed during logging operations.
BIODIVERSITY & AGRICULTURE
Thomas Jefferson once wrote that “the greatest service which can be rendered any country is to add a useful plant to its culture, especially a breadgrain.” It has been estimated that there are almost 80,000 species of edible plants, of which fewer than 20 produce 90 percent of the world’s food. If underutilized species are conserved, they could help to feed growing populations. One grain native to the Great Lakes States, Indian wild rice, is superior in protein to most domesticated rice, and its increasing commercial production earns millions of dollars annually.
Many individual species are uniquely important as indicators of environmental quality. The rapid decline in bald eagles and peregrine falcons in the mid-20th century was a dramatic warning of the dangers of DDT—a strong, once widely used pesticide that accumulates in body tissues. (It hampered fertility and egghatching success in these species.) In another example, lichens and certain plants like the eastern white pine are good indicators of excess ozone, sulfur dioxide, and other air pollutants. Species like these can alert us to the effects of some contaminants before more damage is done.
Freshwater mussels are also very effective environmental indicators. The eastern United States boasts the richest diversity of freshwater mussels in the world. These animals are filter feeders, drawing in water and straining out food particles. Their method of feeding helps to keep our waters clean. But because mussels filter material from the water, they are often the first animals to be affected by water pollution. They tend to accumulate whatever toxins, such as chemicals in agricultural and industrial runoff, are present in their habitat. Too much pollution can eliminate the mussels. Other threats to mussel populations include siltation, the introduction of competing nonnative mussels, stream channelization and dredging, and the impoundment of free-flowing streams and rivers. Today, most native freshwater mussel species are considered to be endangered, threatened or of special concern.
As the pioneering naturalist Aldo Leopold once stated, “To keep every cog and wheel is the first precaution of intelligent tinkering.” As we tinker with ecosystems through our effects on the environment, what unexpected changes could occur? One subject of increasing concern is the impacts these effects can have on “ecosystem services,” which is a term for the fundamental life-support services provided by our environment.
Ecosystem services include air and water purification, detoxification and decomposition of wastes, climate regulation, regeneration of soil fertility, and the production and maintenance of biological diversity. These are the key ingredients of our agricultural, pharmaceutical, and industrial enterprises. Such services are estimated to be worth trillions of dollars annually. Yet because most of these services are not traded in economic markets, they carry no price tags that could alert society to changes in their supply or declines in their functioning. We tend to pay attention only when they decline or fail.
An emerging field called phytoremediation is an example of the ecosystem services provided by plants. Phytoremediation is a process that uses plants to remove, transfer, stabilize and destroy contaminants in soil and sediment. Certain plant species known as metal hyperaccumulators have the ability to extract elements from the soil and concentrate them in the easily harvested plant stems, shoots, and leaves. The alpine pennycress, for example, doesn’t just thrive on soils contaminated with zinc and cadmium; it cleans them up by removing the excess metals. In the home, houseplants under some conditions can effectively remove benzene, formaldehyde and certain other pollutants from the air.
OTHER ECONOMIC VALUES
Some benefits of animals and plants can be quantified. For example, the Texas Parks and Wildlife Department calls birding “the nation’s fastest growing outdoor recreation.” It estimates that birders pump an estimated $400 million each year into the state’s economy. A host of small rural towns host festivals to vie for the attention of these birders. Nationwide, the benefits are even more amazing. Wildlife watching—not just bird watching—generates billions of dollars in economic benefits to nations each year.
If imperiled plants and animals lack a known benefit to mankind, should we care if they disappear? If a species evolves over millennia or is created by divine intent, do we have a right to cause its extinction? Would our descendants forgive us for exterminating a unique form of life? Such questions are not exclusive to scientists or philosophers. Many people believe that every creature has an intrinsic value. The loss of plant and animal species, they say, is not only shortsighted but wrong, especially since an extinct species can never be replaced. Eliminating entire species has been compared to ripping pages out of books that have not yet been read. We are accustomed to a rich diversity in nature. This diversity has provided inspiration for countless writers and artists, and all others who treasure variety in the natural world.
The giraffe is loved and known across the world, but very few people are aware that we are losing both this iconic species and its close relative, the okapi, at an unprecedented and alarming rate.
Giraffe and okapi are the only living species in the Giraffidae family and share a number of common features, such as elongated necks and long, dark-colored tongues (both adaptations for feeding on tree leaves). The giraffe is found in savannah regions of 21 countries across sub-Saharan Africa while okapi are restricted to the dense, lowland rainforests of central and north-eastern Democratic Republic of Congo (DRC).
Giraffe numbers have plummeted from 140,000 in the late 1990s to less than 80,000 today. In the past 30 years, giraffes have become extinct in at least 7 African countries and okapi numbers are thought to have halved. This dramatic loss has gone largely unnoticed. The main threats to both species are habitat loss and, increasingly, hunting and poaching.
Giraffes, as well as all 9 subspecies, are expected to end up in one of the IUCN Red List threatened categories. The okapi was recently listed as ‘Endangered’ on the IUCN Red List.
The giraffe is an African icon and the drop in numbers surprises even the most seasoned conservationists, as giraffes appear to be everywhere. Recent research is only starting to paint the bleak picture facing these gentle giants. It is time for the international community to stick their necks out to save giraffes before it is too late.
Despite being one of the most iconic and recognizable animals in the world, giraffes are probably the least researched large mammals in Africa. New studies are providing important information on the ecology, population and distribution of giraffes and okapi, shedding light on poorly-understood behaviors such as the function of all-male giraffe herds and the leadership role taken by older females in the group. But we still know little about these animals and more research is needed, as well as improved monitoring of both species.
Strategies for preserving tropical forests can operate on local to international scales. On a local scale, governments and non-governmental organizations are working with forest communities to encourage low-impact agricultural activities, such as shade farming, as well as the sustainable harvesting of non-wood forest products such as rubber, cork, produce, or medicinal plants. Parks and protected areas that draw tourists—ecotourism—can provide employment and educational opportunities for local people as well as creating or stimulating related service-sector economies.
On the national scale, tropical countries must integrate existing research on human impacts on tropical ecosystems into national land use and economic development plans. For tropical forests to survive, governments must develop realistic scenarios for future deforestation that take into account what scientists already know about the causes and consequences of deforestation, including the unintended deforestation that results from road-building, accidental fire, selective logging, and economic development incentives such as timber concessions and agricultural subsidies.
Scientists are encouraging the conservation community to re-consider the belief that vast, pristine parks and protected areas are the holy grail of forest conservation. Scientists using satellite and ground-based data in the Amazon demonstrated that far less “unfettered” deforestation occurred in recent decades within territories occupied and managed by indigenous people than occurred in parks and other protected areas. The deforestation in the protected areas resulted from a combination of illegal logging and devastating fires that raged through logging-damaged forests during drought. While some might argue that these losses could be prevented in the future through better enforcement of environmental laws, it may also be true that inhabited forest reserves are a more realistic strategy for preserving the majority of biodiversity in larger areas than parks alone can accomplish.
Finally, on the national and international scale, an increasing value in the global marketplace for products that are certified as sustainably produced or harvested—timber, coffee, soy—may provide incentives for landowners to adopt more forest-friendly practices, and for regional and national governments to create and enforce forest-preservation policies. Direct payments to tropical countries for the ecosystem services that intact tropical forest provide, particularly for carbon storage to offset greenhouse gas emissions, are likely to become an important international mechanism for sustaining tropical forests as more countries begin to seriously tackle the problem of global warming.
Earth isn’t perfectly round. Earth is thicker around the equator, the belt around the middle. How much thicker? Well, it’s about 0.3% thicker. It’s not much, so when you see a photo of Earth, it appears round. But it’s just barely not.
Days are getting longer. When Earth first formed 4.6 billion years ago, a day was about six hours long. Since then, the Earth has slowed down. It takes longer to spin around. Every 100 years, the day gets 0.0017 seconds longer. Why? The moon is slowing down Earth’s rotation with the tides it creates. As the tides rise and fall all over Earth, it creates a force that slows down Earth’s rotation.
Continents are always on the move. About 250 million years ago, all the continents we see today were one big supercontinent called Pangaea. They’ve slowly moved ever since to spread out and form the continents we see today: North America, South America, Africa, Europe, Asia, Australia, and Antarctica. But Pangaea wasn’t the first supercontinent. About 800 million years ago, all the continents were pushed together too. We call this previous supercontinent Rodinia.
There wasn’t just one Ice Age. You may have heard of the Ice Age on Earth. It was a time when woolly mammoths roamed. But this didn’t just happen one time 30,000 years ago. There may have been as many as four different Ice Ages in the past. During these times, Earth would have been covered completely in ice.
The driest place on Earth is near the ocean. The Atacama Desert in northern Chile is the driest place on Earth. It is said that a city there went without rain for 400 years! And yet, this desert is right next to the biggest body of water on Earth, the Pacific Ocean. Do you know what they say about the ocean? Water, water everywhere, but not a drop to drink.
Earth’s gravity isn’t the same everywhere on Earth. If the Earth were smooth and perfect, gravity would be the same everywhere. But Earth has mountains, oceans, valleys, and other features. The differences in gravity across Earth are called gravity anomalies. A mission called GRACE (Gravity Recovery and Climate Experiment) has a satellite that orbits Earth and maps the gravity across the surface.
Sea levels have changed in the past. During the last Ice Age, so much water was trapped in icy glaciers that the sea level dropped by as much as 390 feet (120 meters). That’s about as tall as building 40 stories high. Long before that, the sea level was actually much higher than it is now. It was as much as 230 feet higher. There are parts of land today that used to be far beneath the ocean waters.
The sun won’t shine forever. Don’t worry, the sun isn’t going anywhere for a very long time. But nothing in the whole universe lasts forever and ever. Our sun will run out of energy in about five billion years. If anyone is around when it happens, they’ll have to leave Earth and find a new planet. Luckily, we have these next five billion years to plan for that.
Earth has other “moons.” Besides our moon, there are two other objects in space that orbit near Earth. They're not truly "moons," but they are there. One of them is an asteroid that follows Earth as we orbit around the sun. It’s called Cruithne. A different asteroid orbits the sun near us but its orbit is horseshoe-shaped, so it only gets near Earth every 95 years.
Before a big storm hits, sometimes there is a moment of calm. When a storm grows, it pulls in warm, wet air around it. The air goes into the storm cloud, and when it gets to the top, it rolls out over the big head of the cloud. Then it falls back down. As it falls, it becomes warmer and drier, which makes for stable, calm weather. This is the calm that can happen right before the storm hits.
Descendants of monkeys found in Africa and Arabia, gorillas are herbivorous apes found only in the African continent. There are two broad species of this African animal. One is the Eastern gorilla and the other the Western gorilla. The Eastern gorilla has two subspecies. The Western gorilla also has two subspecies. All gorilla species are listed as endangered by the International Union for Conservation of Nature (IUCN).
Gorilla populations have been greatly reduced by habitat loss, disease and poaching. Protecting gorilla populations has proved difficult due to the vast dense areas in which they live. Conservation efforts by governmental and non governmental organizations are desperately trying to save gorillas from extinction.
The Eastern Lowland gorilla, or Grauer's gorilla, is mostly found on the plains and lower slopes of the Virunga volcanic mountains of Central Africa. This habitat area of the ape entirely falls in the Eastern part of the Democratic Republic of Congo (DRC). This huge, hairy ape, with a shiny black coat, can measure up to 5 feet-6 inches while standing to its full height. They weigh as much as 550 lbs or 250 kilograms. The population of this subspecies has been reduced from around 5,000 in 2004 to only 3,800 .
The mountain gorillas are an endangered species exclusively dwelling in the Rwandan half of the Virunga volcanic mountains at altitudes of 7,000 to 14,000 feet. Like their Eastern lowland cousins, they have jet black hair but with a slight bluish tinge. While standing totally erect, the mountain gorilla is an impressive sight. Reaching a height of 6 feet-2 inches, it has an enormous arm span of 8 feet-6 inches and can weigh almost 500 lbs. There are only 880 of this sub-species left. Mountain gorillas were popularized by the film "Gorillas of the Mist" that portrayed the life of Diane Fossey, who spent two intrepid decades in the Rwandan mountains studying and fighting for the preservation of the apes.
For the mountain gorillas, major threats come from forest clearance and degradation as poor Rwandans desperately try to eke out a living. Clearing out land for agriculture and deforestation for firewood also puts a lot of pressure on the natural resources of the region and eventually on the habitat of these rare apes.
The Western lowland gorilla's habitat spans plains, forests and swamps of countries like Angola, Cameroon, Central African Republic, DRC, Equatorial Guinea and Gabon. They are smaller in size to the Eastern gorillas and have longer black hair covering almost their entire body. They number almost 125,000 and are inhumanely kept captive in zoos all over the world for human entertainment and profit.
The Cross River gorilla is a species found essentially in the Cross-Niger transition forests on the western half of the Cross River flowing into South-western Nigeria. Most of these hilly forests fall in Cameroon. They are a distinctive sub-species with short body hair and shorter skulls, smaller palates and smaller cranial vaults compared to the Western lowland gorillas.
The Western gorillas, that inhabit as many as 11 countries of Western Africa, are under threat from logging, hunting, disease and even trigger-happy militia. They often come into direct confrontation with man. Many of them are killed for their meat by impoverished and hungry tribesmen. Apes can be seen as a nuisance, too. Forced to move away from a shrinking habitat, the animals raid crops. A single group of gorillas can easily destroy an entire harvest. Villagers feel they have no recourse but to kill the animals. Only 250 to 300 of these creatures are left, making them one of the most endangered animals on the planet.
Threats To Gorillas
The greatest threat to gorillas is human poverty. They inhabit countries which are among the poorest in the world but with a high density of human population.
Being closely related to the humans anatomically, apes are susceptible to disease as much as man. Not just from poachers and militia groups, but exposure to well-meaning humans like tourists, conservationists, scientists, rangers and local communities poses a threat. Gorillas have been known to succumb to skin diseases and respiratory disorders. Outbreaks of Ebola can take many more gorilla lives than humans.
Poaching of infant mountain gorillas to cater to the illicit animal trade became a common threat in the early 2000s. Civil unrest also took a toll on the apes. The Rwandan genocide of the 1990s, and the Angolan wars of the 1980s, had an unsettling effect on the movement and habitat of gorillas. Large movements of refugees fleeing unrest, debris left behind by them, and warring militias posed major threats.
Weak local governments, virtual absence of forest regulations or conservation policies, and impoverished and disenchanted local communities all pose serious challenges to the survival of the apes.
The only ray of hope for saving gorillas from extinction is conservation. A gradual rise in the population of mountain gorillas has taken place thanks to conservation programs. From the lowest point in 1980 when its numbers were just 254, it has now grown to 880.
Similar efforts in the Campo Ma’an National Park in Cameroon and Cross River National Park of Nigeria has held some hope for the tiny population of Cross-river gorillas dwelling there. Recent surveys show that the counts for these apes have not gone below the 300 mark.
But applying conservation measures to the lowland gorillas will be far more challenging given their wider habitat coverage. Efforts must be made to save the apes before it's too late.
More than half the world’s sea turtles have ingested plastic or other human rubbish. Recent research indicates that approximately 52 percent of turtles world-wide have eaten debris.
Threats to marine turtle species come from an estimated four million to 12 million tons of plastic which enter the oceans annually. Plastic ingestion can kill turtles by blocking the gut or piercing the gut wall, and can cause other problems through the release of toxic chemicals into the animals’ tissues.
Plastics and other litter that enter marine environments are mistaken for food or eaten accidentally by turtles and other wildlife. Olive ridley turtles (Lepidochelys olivacea) are at the highest risk, due to their feeding behavior and distribution. Olive ridley turtles commonly eat jellyfish and other floating animals, and often feed in the open ocean, where debris accumulates.
The east coasts of Australia and North America, Southeast Asia, southern Africa, and Hawaii are particularly dangerous for turtles due to a combination of debris loads and high species diversity.
Other reptiles, aquatic mammals and fish are common victims of ocean litter. Seabirds are especially high risk for for marine debris. A study discovered that more than 60 percent of seabird species had ingested debris, and that number is expected to reach 99 percent by 2050.
Approximately one-third of the Earth's land surface is desert, arid land with meager rainfall that supports only sparse vegetation and a limited population of people and animals. Deserts stark, sometimes mysterious worlds have been portrayed as fascinating environments of adventure and exploration from narratives such as that of Lawrence of Arabia to movies such as "Dune." These arid regions are called deserts because they are dry. They may be hot, they may be cold. They may be regions of sand or vast areas of rocks and gravel peppered with occasional plants. But deserts are always dry.
Deserts are natural laboratories in which to study the interactions of wind and sometimes water on the arid surfaces of planets. They contain valuable mineral deposits that were formed in the arid environment or that were exposed by erosion. Because deserts are dry, they are ideal places for human artifacts and fossils to be preserved.
Deserts are also fragile environments. The misuse of these lands is a serious and growing problem in parts of our world.
There are almost as many definitions of deserts and classification systems as there are deserts in the world. Most classifications rely on some combination of the number of days of rainfall, the total amount of annual rainfall, temperature, humidity, or other factors. In 1953, Peveril Meigs divided desert regions on Earth into three categories according to the amount of precipitation they received. In this now widely accepted system, extremely arid lands have at least 12 consecutive months without rainfall, arid lands have less than 250 millimeters of annual rainfall, and semiarid lands have a mean annual precipitation of between 250 and 500 millimeters. Arid and extremely arid land are deserts, and semiarid grasslands generally are referred to as steppes.
How The Atmosphere Influences Aridity
We live at the bottom of a gaseous envelope since the atmosphere is bound gravitationally to the planet. The circulation of our atmosphere is a complex process because of the Earth's rotation and the tilt of its axis. The Earth's axis is inclined 231/2° from the ecliptic, the plane of the Earth's orbit around the Sun. Due to this inclination, vertical rays of the sun strike 231/2° N. latitude, the Tropic of Cancer, at summer solstice in late June. At winter solstice, the vertical rays strike 23 1/2° S. latitude, the Tropic of Capricorn.
In the Northern Hemisphere, the summer solstice day has the most daylight hours, and the winter solstice has the fewest daylight hours each year. The tilt of the axis allows differential heating of the Earth's surface, which causes seasonal changes in the global circulation. On a planetary scale, the circulation of air between the hot Equator and the cold North and South Poles creates pressure belts that influence the weather. Most of the nonpolar deserts lie within the two trade winds belts. Air warmed by the sun rises at the Equator, cools as it moves toward the poles, descends as cold air over the poles, and warms again as it moves over the surface of the Earth toward the Equator.
This simple pattern of atmospheric convection, however, is complicated by the rotation of the Earth, which introduces the Coriolis Effect. To appreciate the origin of this effect, consider the following. A stick placed vertically in the ground at the North Pole would simply turn around as the Earth rotates. A stick at the Equator would move in a large circle of almost 40,000 kilometers with the Earth as it rotates.
The Coriolis Effect illustrates Newton's first law of motion: a body in motion will maintain its speed and direction of motion unless acted on by some outside force. Thus, a wind traveling north from the equator will maintain the velocity acquired at the equator while the Earth under it is moving slower. This effect accounts for the generally east-west direction of winds, or streams of air, on the Earth's surface. Winds blow between areas of different atmospheric pressures. The Coriolis Effect influences the circulation pattern of the Earth's atmosphere. In the zone between about 30° N. and 30° S., the surface air flows toward the Equator and the flow aloft is poleward. A low-pressure area of calm, light variable winds near the equator is known to mariners as the doldrums.
Around 30° N. and S., the poleward flowing air begins to descend toward the surface in subtropical high-pressure belts. The sinking air is relatively dry because its moisture has already been released near the Equator above the tropical rain forests. Near the center of this high-pressure zone of descending air, called the "Horse Latitudes," the winds at the surface are weak and variable. The name for this area is believed to have been given by colonial, sailors, who, becalmed sometimes at these latitudes while crossing the oceans with horses as cargo, were forced to throw a few horses overboard to conserve water.
The surface air that flows from these subtropical high-pressure belts toward the Equator is deflected toward the west in both hemispheres by the Coriolis Effect. Because winds are named for the direction from which the wind is blowing, these winds are called the northeast trade winds in the Northern Hemisphere and the southeast trade winds in the Southern Hemisphere. The trade winds meet at the doldrums. Surface winds known as "westerlies" flow from the Horse Latitudes toward the poles. The "westerlies" meet "easterlies" from the polar highs at about 50-60° N. and S. Near the ground, wind direction is affected by friction and by changes in topography. Winds may be seasonal, sporadic, or daily. They range from gentle breezes to violent gusts at speeds greater than 300 kilometers/hour.
Where Deserts Form
Dry areas created by global circulation patterns contain most of the deserts on the Earth. The deserts of our world are not restricted by latitude, longitude, or elevation. They occur from areas close to the poles down to areas near the Equator. The People's Republic of China has both the highest desert, the Qaidam Depression that is 2,600 meters above sea level, and one of the lowest deserts, the Turpan Depression that is 150 meters below sea level.
Deserts are not confined to Earth. The atmospheric circulation patterns of other terrestrial planets with gaseous envelopes also depend on the rotation of those planets, the tilts of their axes, their distances from the sun, and the composition and density of their atmospheres. Except for the poles, the entire surface of Mars is a desert. Venus also may support deserts.
Forest biomes are dominated by trees and extend over one-third of the earth's land surface. There are three main types of forests—temperate, tropical and boreal. Each type has a different assortment of animals, climate characteristics and species compositions.
● Temperate forests are in temperate regions of the earth including North America, Europe and Asia. They have four well-defined seasons and a growing season between 140 and 200 days. Rainfall takes place throughout the year and soils are nutrient-rich.
● Tropical forests are located in equatorial regions between 23.5°N and 23.5°S latitude. They experience two seasons, a dry season and a rainy season. The length of each day varies little throughout the year. Soils in tropical forests are nutrient-poor and acidic.
● Boreal forests make up the largest terrestrial habitat. They are a band of coniferous forests located in the high northern latitudes between about 50°N and 70°N. Boreal forests create a circumpolar band of habitat from Canada, to northern Europe, to eastern Russia. They are bordered by tundra habitat to the north and temperate forest habitat to the south.
Some of the wildlife that inhabit the forest biome include deer, bears, wolves, moose, caribou, gorillas, squirrels, chipmunks, birds, reptiles and insects.
Temperate forests are found in a wide range of climates and are some of the richest habitats earth. Temperate forests are home to a variety of plants and animals. Some live within them year-round, while migratory animals visit them seasonally.
The two main types of temperate forests are deciduous forests and evergreen forests.
Deciduous forests contain trees that loose their leaves in the fall. They are usually located in the Northern Hemisphere in parts of North America, Europe and Japan.
Evergreen forests are made up of trees that don't lose their leaves in the fall. They usually are found in warmer climates in South America, southern Europe, South Africa and parts of southern Australia. A more varied range of wildlife is often found in evergreen forests than deciduous forests.
A wide variety of animals call temperate forests home. Mammals, reptiles, amphibians, birds and insects live in temperate forests. The most common mammals are deer, squirrels, birds and wild boars.
Since food is plentiful in evergreen forests year round, even more varieties of wildlife inhabit them. Reptiles, amphibians, birds, mammals and insects are plentiful in evergreen forests.
Temperate forests once covered huge areas of the Northern Hemisphere. As a result of logging and deforestation for agriculture, most forests are already gone.
Coniferous forests are located in the far north, many within the Arctic Circle. They are predominantly home to conifers, the toughest and longest living trees. Conifers grow close together resulting in dense forests that are sheltered.
Coniferous forests include boreal forests and temperate forests.
Boreal forests stretch across the far north. Temperate coniferous forests are located in western North America, New Zealand and Chile. Some trees in the temperate coniferous forests in North America are over 500 years old.
Boreal coniferous forests stretch across the far north from Siberia, through Northern Europe, to Alaska, covering a distance of 6 million square miles. They are 1,000 miles wide in places. A large proportion of boreal coniferous forest is in the Arctic Circle, where plants and animals are well adapted to cold temperatures.
While fewer plant and animal species are found in coniferous forests compared to temperate forests and rainforests, many plants and animals still live within them. Conifer trees withstand the cold. Their pine needles are acidic, which passes into the soil when needles drop, allowing only acid loving plants to survive in coniferous forests. Only herbivores that survive on acidic plants can inhabit coniferous forests.
Insects make up the majority of animals found in coniferous forests. The dense trees provide ideal habitat for them to build their nests. Deer, elk, wolves and bears are also common in coniferous forests.
Coniferous forests are the least affected forests by humans. The trees are softwood and usually only used for making paper. Larger areas of coniferous forests are being logged however, as paper demand increases.
Rainforests are home to more than 50% of all living species on the planet. They receive an abundance of rain and contain extremely diverse wildlife. The two main types of rainforest are tropical rainforests and seasonal rainforests.
Tropical rainforests are close to the Equator where the climate is warm, providing ideal conditions for plants. 170,000 of the world’s 250,000 known plant species are found in tropical rainforests. They have various layers of canopy providing a wide variety of habitats for animals. A large collection of tall tree species is made possible by a constant water flow. Tropical forests are home to smaller primates and bird species than seasonal rainforests.
Seasonal rainforests are usually further away from the Equator. Their climate is less stable then tropical rainforests. Rather than rain being dispersed evenly throughout the year, it comes all at once in what is called the monsoon. Trees in seasonal rainforests are generally much smaller than those in tropical rainforests. Larger animals inhabit the changing seasonal rainforests, such as tigers, primates and large snakes.
The broad array of animals found in rainforests include mammals, reptiles, birds and invertebrates. Mammals include primates, wildcats and tapirs. Reptiles include a variety of snakes, turtles and lizards. Numerous species of birds and insects live in rainforests. Fungi is common, which feed on the decomposing remains of plants and animals. Many animal species have adopted a tree-dwelling (arboreal) lifestyle in the rainforest. Food is abundant in the forests due to the amount of water and plant life.
Numerous plant and animal species are rapidly disappearing from rainforests due to deforestation, habitat loss and other human activities. Around 50 million people live in rainforests. Their habitat and culture is also threatened as an alarming amount of rainforest land disappears each year.
A habitat consists of the ecosystem or environment in which an animal, plant or other living organism has lived and evolved over a considerable period of time. A habitat provides all the necessary ingredients they need to survive - food, water, shelter, the right temperatures, resources to ward off possible predators, and the right environs for reproduction and avoiding disease.
Without a habitat, a creature is virtually homeless and faces certain death. The habitat is a complete and intricate network of dependability provided to a species or many species by nature. A decimation of a habitat could spell doom for the biodiversity thriving in it, be it animals, insects, plants and other organisms.
Causes Of Loss Of Habitat
Causes of habitat loss can be natural factors like climate changes or catastrophes such as flooding, earthquakes, storms, volcanoes or other geological changes. Habitat loss can also be man-made. Excessive exploitation and destruction of natural resources through logging, fishing, mining, oil and gas exploration, development, road construction, animal agriculture, callous disposal of industrial waste and the introduction of unwanted species all contribute in depleting or destroying the richness of habitats.
Fragmentation and alteration of natural habitats are also serious threats to ecostystems.
Habitat Loss And Endangered Species
85 percent of species on the IUCN's Red List are considered truly threatened by loss of their habitats. For endemic species, the ones that are only to be found in one particular kind of habitat uniquely suited to its survival, the challenge to ward off extinction is truly serious. When an endemic species' habitat is destroyed, it has no other ecosystem to fallback on like generalized species. In absence of a suitable habitat, death becomes imminent.
Habitats of many species could cover large areas and overlap. But for species with extremely low populations, habitats are specialized and small, making them susceptible to extinction. In the event of catastrophes, the genetic limitations of a threatened species make it almost impossible to survive. The lack of genetic diversity among critically endangered species also breeds reproductive failure.
Tools used to measure habitat size are more scaled towards those with large contiguous areas than smaller ones. In the 1970s and 1980s, the debate over whether a single large or several small reserves was the answer to optimum conversation ultimately saw the emergence of the former theory as the accepted premise that large-sized habitats proved better survival grounds than smaller habitats. Bigger habitats act as buffers to human disruptions and also facilitates migration and food gathering.
Presently, conservation efforts are dictated by the habitat condition or status of an endangered species. Certain delicate ecosystems and bio-diversities warrant conservation endeavors to such a degree that they fall under the category of biodiversity "hotspots". Endemic wildlife and near-extinction species harbored by such ecosystems are the focus of intense conservation efforts. Much of the risk comes from human encroachment.
Nearly 34 places of the world have been identified as biodiversity hotspots. These cover almost 2.3 percent of the earth's surface, but have lost almost 70 percent of their original vegetation. Endemic to these hotspots are an astonishing 50 percent of the world's plant species, and 42 percent of animal species. Efforts to preserve such biodiversity zones are at the forefront of conservation endeavors.
But while around 98% of the Earth has less species diversity, these ecosystems need just as much help as areas with lots of biodiversity. In fact, some biodiversity "coldspots" are home to very rare plants and animals. Protecting these areas before too much destruction occurs prevents us from having to work backwards.
Wilderness or wildlands are natural places on our planet that have not been significantly modified by humans. These last, truly wild places that have not been developed with industry, roads, buildings and houses are critical for the survival of many plant and animal species. They also provide humans with educational and recreational opportunities, and are deeply valued for aesthetic, cultural, moral and spiritual reasons.
Some wildlands are protected, preserving natural areas for humans, animals, flora and fauna. Others are dissapearing at alarming rates, and simply drawing lines around specific areas is not enough. All of our planet is intricately connected. What happens outside a specific wilderness area affects what happens inside it.
Many wildlife habitats have become fragmented due to human development. Without the protection of vast expanses of wildlands to meet the minimum requirements of the largest, most widely roaming members of the ecosystem, they may dwindle or vanish forever. The loss of any species effects the entire ecosystem.
Biomes, or ecosystems, are large regions of the planet with shared characteristics such as climate, soils, plants and animals. Climate is an important factor that shapes the nature of an ecosystem, as well as precipitation, humidity, elevation, topography and latitude.
The five major biomes include aquatic, desert, forest, grassland and tundra biomes. Each biome also includes numerous types of sub-habitats.
By protecting and preserving ecosystems, we protect and preserve plant and animal species...including our own species.
Widely hailed as a renewable natural resource, tropical timber from old-growth
tropical forests is selectively logged worldwide at an unprecedented scale. But
research now reveals that these sources of timber are far from sustainable and
Studies reveal that once prime tropical hardwoods – such as Brazilian cedars, ipe
(Brazilian walnut), and rosewood – have been logged, they do not grow back to
commercial levels and are at risk from disappearing altogether.
Slow growing and "commercially valuable" species of all kinds have been overexploited
over the course of human history – just look at the whaling industry or fisheries.
Yet many tropical timber species are still thought of as a renewable resource.
We are only beginning to see over-exploitation parallels in tree species. Many
high-value timber species are logged until their populations collapse altogether.
Timber harvests in Pará equate to almost half of all native forest roundlog production
in Brazilian Amazonia – the largest old-growth tropical timber reserve controlled
by any country. Brazil accounts for 85 percent of all native neotropical forest
roundlog production. Researchers have found that loggers can no longer depend
on areas where high-value species were formerly abundant to fetch high economic
returns. This means that logging operations are continuously forced to extract
timber trees from new areas of unlogged primary forests.
Even so-called ‘reduced-impact logging’ in tropical forests can rarely be defined
as sustainable in terms of forest composition and dynamics in the aftermath of
logging – never mind the greater susceptibility of logged forests to catastrophic
fires. Environmental licensing and market certification of logging concessions
need to take this into account, and review minimum preconditions in terms of
volumetric quotas of roundlogs harvested per species and regeneration standards
over multi-decade logging cycles.
After selective logging, there is no evidence that the composition of timber species
and total forest value recovers beyond the first-cut. The most commercially-valuable
timber species become predictably rare or economically extinct in old logging
Only recent logging operations, which are furthest away from heavy-traffic roads,
are the most selective, concentrating gross revenues on a few high-value species.
Managing yields of selectively-logged forests is crucial for the long-term integrity
of forest biodiversity and financial viability of local industries.
Current commercial agreements could lead to ‘peak timber’ and then widespread economic
extinctions across other tropical regions. We can already see a market shift,
in which loggers in old depleted logging Amazonian frontiers are forced to depend
on fast growing, soft-wood timber species.
Around half of the planet's population now lives in a city. The move towards urban living has increased city sizes tremendously with an enormous impact on ecosystems. Once wild landscapes have been transformed into urban centers, changing animal habitats both inside and outside the areas.
Animals in these areas have had to adapt. They have learned to create new homes within their artificial environments. They have also discovered new food sources, including waste created by humans. Food chains of numerous species have been altered.
Urban areas range from fully urban with little green space and mostly covered by paving or buildings, to suburban areas with gardens and parks. Different types of urban areas support different kinds of wildlife. Some animals find shelter in city parks, trees and water sources. Some live inside the city; others just outside the urban habitat.
Insects, reptiles and rodents make nests inside buildings in small gaps and crevices to find shelter from the elements and protection from predators. Birds nest on buildings. Some animals live under homes and buildings. Some make homes in city sewer systems.
Animals have cleverly adapted to their changing world. Some city animals have become nocturnal, using city lights to aid in finding prey. Feral dogs have learned to use subway systems. Urban monkeys and penguins raid human homes to take food. Some steal fruit from vendors. Older deer learn to look both ways before crossing streets. Birds flock to city centers to snack on the food dropped in the streets.
Numerous threats for urban animals include traffic, litter, pollution, noise pollution, bright lighting and lack of space.
It is important to reserve space within urban environments for wildlife, and to conserve natural environments outside cities.
Woodchucks are harmless, comical vegetarians who are commonly sighted in suburban backyards and along roadways. Conflicts usually arise over who gets to eat the garden vegetables. Suburban landscapes provide perfect habitat for woodchucks. Our raised decks provide cover and a perfect place to raise young, and our lush lawns provide a virtual buffet. Most woodchuck conflicts occur in spring and summer, just when birthing season has begun. That's why problems need to be solved in a way that doesn't leave orphaned young behind.
KEEPING WOODCHUCKS OUT OF GARDENS
The best way to exclude woodchucks is by putting up a simple chicken wire or mesh fence. All you need is a roll of 4-foot high chicken wire and some wooden stakes. Once the job is done, it won't matter how many woodchucks are in the neighborhood because they won't be getting into your garden.
There are 2 secrets for making a successful fence:
Tip #1: The top portion of the fence only needs to be 2 ½ to 3 feet high but it should be staked so that it's wobbly -- i.e. the mesh should not be pulled tight between the stakes but rather, there should be some "give" so that when the woodchuck tries to climb the fence, it will wobble which will discourage him. Then he'll try to dig under the fence, so:
Tip #2: Extend your mesh fence 4 inches straight down into the ground and then bend it and extend the final 8-12 inches outward, away from the garden, in a "L"-shape which creates a false bottom (you can also put this mesh "flap" on top of the ground but be sure to secure it firmly with landscaping staples or the woodchuck will go under it). When the woodchuck digs down and hits this mesh flap, he'll think he can't dig any farther and give up. It won't occur to him to stand back a foot and THEN start digging!
IF YOU AREN'T WILLING TO PUT UP A FENCE, you can also try the following scare techniques, which do work in some cases:
1) Line your garden with helium-filled, silver mylar balloons or make a low fence of twisted, reflective mylar tape bought at your local party store. Be sure to purchase heavier weights to attach to the bottom of the balloons. The balloons bobbing in the wind will scare the woodchucks.
2) Sprinkle cayenne pepper around the plants and spray your plants with a taste repellent such as Ropel (available at garden stores) every 2 weeks.
GETTING WOODCHUCKS OUT FROM UNDER SHEDS
Woodchucks don't undermine foundations and really aren't likely to damage your shed. In spring and summer, the woodchuck under your shed is probably a mother nursing her young, which is why you should consider leaving them alone. Be sure you really need to evict the woodchuck before taking action. If you must, put some dirty kitty litter down the woodchuck burrow -- the urinated part acts as a predator odor, which often causes the entire family to leave. Ammonia-sprinkled rags or sweaty, smelling socks placed in the burrow may also cause self-eviction.
WOODCHUCKS & CHILDREN
Woodchucks are harmless vegetarians who flee when scared. Remember that even a small child looks like a giant predator to the woodchuck. There is no cause for alarm. Woodchucks live under houses and day care centers all over the country. Healthy woodchucks simply don't attack children or pets. If chased, woodchucks will quickly flee to their burrows.
WOODCHUCKS & RABIES
Woodchucks have a higher susceptibility to rabies than other rodents, yet the incidence of rabies in woodchucks is still very low. Woodchucks are much more susceptible to the roundworm brain parasite, which causes symptoms that look exactly like rabies. Roundworm is NOT airborne -- it can only be transmitted through the oral-fecal route, i.e. the ingestion of an infected animal's feces.
SETTING A TRAP FOR WOODCHUCKS & CATCHING A SKUNK
This is a common occurrence when traps are left open at night. You can let the skunk out without getting sprayed just by knowing that skunks have terrible eyesight and only spray when something comes at them fast, like a dog. If you move slowly and talk soothingly, you shouldn't get sprayed. Skunks stamp their front feet as a warning when they're nervous, so if the skunk stamps, just remain motionless for a minute until he stops stamping, then proceed. You can drape a towel -- slowly-- over the trap prior to opening it. Once the trap door is opened, the skunk will beeline for home. If you must trap and relocate a woodchuck, remember to close the trap at night so another skunk doesn't get caught.
Trapping won't solve the problem. As long as woodchuck habitat is available, there will be woodchucks. Even in studies where all the woodchucks are trapped out of an area, others from the surrounding area quickly move into the vacated niche. In addition, trapping and relocating woodchucks may lead to starving young being left behind. Homeowners are then horrified to smell a foul odor. It's much more effective to simply exclude woodchucks from areas where they're not wanted. Don't trap unless an animal is stuck somewhere and can't get out, or poses an immediate threat to humans or domestic animals.
Human impact continues to have a devastating effect on the natural world, with wildlife species across the globe under threat from poaching, hunting and the consequences of climate change. Recent studies indicate that 59 percent of the world's largest carnivores and sixty percent of the largest herbivores are currently threatened with extinction.
Scores of species across the globe, including tigers, lions and rhinos, are at risk of extinction due to a plethora of threats imposed by mankind. We will lose many of these incredible species unless swift, decisive and collective action is taken by the global community.
Every country should strive to do more to protect its wildlife, but the richest countries, who can afford to do the most, are not doing enough. Less affluent countries are more committed to conservation of their large animals than richer ones. In comparison to the more affluent, developed world, biodiversity is a higher priority in poorer areas such as the African nations, which contribute more to conservation than any other region.
Researchers from Oxford's Wildlife Conservation Research Unit (WildCRU) have created a Mega-Fauna Conservation Index (MCI) of 152 nations to evaluate their conservation footprint. The benchmarking system evaluates three key measures: a) the proportion of the country occupied by each mega-fauna species that survives in the country (countries with more species covering a higher proportion of the country scoring higher); b) the proportion of mega-fauna species range that is protected (higher proportions score higher); c) and the amount of money spent on conservation - either domestically or internationally, relative to GDP.
The findings show that poorer countries tend to take a more active approach to biodiversity protection than richer nations. Ninety percent of countries in North and Central America and 70 percent of countries in Africa are classified as major or above-average in their mega-fauna conservation efforts.
Despite facing a number of domestic challenges, such as poverty and political instability in many parts of the continent, Africa prioritizes wildlife preservation and contributes more to conservation than any other region of the world. African countries make up four of the five top-performing mega-fauna conservation nations, with Botswana, Namibia, Tanzania and Zimbabwe topping the list. By contrast, the United States ranks nineteenth out of the twenty performing countries. Approximately one-quarter of countries in Asia and Europe are identified as significantly underperforming in their commitment to mega-fauna conservation.
Mega-fauna species are associated with strong 'existence values', where just knowing that large wild animals exist makes people feel happier. In some cases, such as the African nations, this link explains why some countries are more concerned with conservation than others. Larger mammal species like wild cats, gorillas and elephants play a key role in ecological processes as well as tourism industries, which are an economic lifeline in poorer regions.
The conservation index is intended as a call to action for the world to acknowledge its responsibility to wildlife protection. By highlighting the disparity in each nations' contributions it hopes to see increased efforts and renewed commitment to biodiversity preservation.
There are three ways countries can improve their MCI scores:
They can 're-wild' their landscapes by reintroducing mega-fauna and/or by allowing the distribution of such species to increase;
They can set aside more land as strictly protected areas;
And they can invest more in conservation, either at home or abroad.
Some of the poorest countries in the world are making the biggest investments in a global asset and should be congratulated. Some of the richest nations just aren't doing enough.
Sand covers only about 20 percent of the Earth's deserts. Most of the sand is in sand sheets and sand seas vast regions of undulating dunes resembling ocean waves "frozen" in an instant of time. Nearly 50 percent of desert surfaces are plains where eolian deflation removal of fine-grained material by the wind has exposed loose gravels consisting predominantly of pebbles but with occasional cobbles. The remaining surfaces of arid lands are composed of exposed bedrock outcrops, desert soils, and fluvial deposits including alluvial fans, playas, desert lakes, and oases. Bedrock outcrops commonly occur as small mountains surrounded by extensive erosional plains.
Oases are vegetated areas moistened by springs, wells, or by irrigation. Many are artificial. Oases are often the only places in deserts that support crops and permanent habitation.
Soils that form in arid climates are predominantly mineral soils with low organic content. The repeated accumulation of water in some soils causes distinct salt layers to form. Calcium carbonate precipitated from solution may cement sand and gravel into hard layers called "calcrete" that form layers up to 50 meters thick.
Caliche is a reddish-brown to white layer found in many desert soils. Caliche commonly occurs as nodules or as coatings on mineral grains formed by the complicated interaction between water and carbon dioxide released by plant roots or by decaying organic material.
Most desert plants are drought-or salt-tolerant. Some store water in their leaves, roots, and stems. Other desert plants have long tap roots that penetrate the water table, anchor the soil, and control erosion. The stems and leaves of some plants lower the surface velocity of sand carrying winds and protect the ground from erosion.
Deserts typically have a plant cover that is sparse but enormously diverse. The Sonoran Desert of the American Southwest has the most complex desert vegetation on Earth. The giant saguaro cacti provide nests for desert birds and serve as "trees" of the desert. Saguaro grow slowly but may live 200 years. When 9 years old, they are about 15 centimeters high. After about 75 years, the cacti are tall and develop their first branches. When fully grown, saguaro are 15 meters tall and weigh as much as 10 tons. They dot the Sonoran and reinforce the general impression of deserts as cacti-rich land.
Although cacti are often thought of as characteristic desert plants, other types of plants have adapted well to the arid environment. They include the pea family and sunflower family. Cold deserts have grasses and shrubs as dominant vegetation.
Rain does fall occasionally in deserts, and desert storms are often violent. A record 44 millimeters of rain once fell within 3 hours in the Sahara. Large Saharan storms may deliver up to 1 millimeter per minute. Normally dry stream channels, called arroyos or wadis, can quickly fill after heavy rains, and flash floods make these channels dangerous. More people drown in deserts than die of thirst.
Though little rain falls in deserts, deserts receive runoff from ephemeral, or short-lived, streams fed by rain and snow from adjacent highlands. These streams fill the channel with a slurry of mud and commonly transport considerable quantities of sediment for a day or two.
Although most deserts are in basins with closed, or interior drainage, a few deserts are crossed by 'exotic' rivers that derive their water from outside the desert. Such rivers infiltrate soils and evaporate large amounts of water on their journeys through the deserts, but their volumes are such that they maintain their continuity. The Nile, the Colorado, and the Yellow are exotic rivers that flow through deserts to deliver their sediments to the sea.
Lakes form where rainfall or meltwater in interior drainage basins is sufficient. Desert lakes are generally shallow, temporary, and salty. Because these lakes are shallow and have a low bottom gradient, wind stress may cause the lake waters to move over many square kilometers. When small lakes dry up, they leave a salt crust or hardpan. The flat area of clay, silt, or sand encrusted with salt that forms is known as a playa. There are more than a hundred playas in North American deserts. Most are relics of large lakes that existed during the last Ice Age about 12,000 years ago. Lake Bonneville was a 52,000-square-kilometer lake almost 300 meters deep in Utah, Nevada, and Idaho during the Ice Age. Today the remnants of Lake Bonneville include Utah's Great Salt Lake, Utah Lake, and Sevier Lake. Because playas are arid land forms from a wetter past, they contain useful clues to climatic change.
Eolian processes pertain to the activity of the winds. Winds may erode, transport, and deposit materials, and are effective agents in regions with sparse vegetation and a large supply of unconsolidated sediments. Although water is much more powerful than wind, eolian processes are important in arid environments.
Wind erodes the Earth's surface by deflation, the removal of loose, fine-grained particles by the turbulent eddy action of the wind, and by abrasion, the wearing down of surfaces by the grinding action and sand blasting of windborne particles.
Most eolian deflation zones are composed of desert pavement, a sheetlike surface of rock fragments that remains after wind and water have removed the fine particles. Almost half of the Earth's desert surfaces are stony deflation zones. The rock mantle in desert pavements protects the underlying material from deflation.
Particles are transported by winds through suspension, saltation, and creep. Small particles may be held in the atmosphere in suspension. Upward currents of air support the weight of suspended particles and hold them indefinitely in the surrounding air. Typical winds near the Earth's surface suspend particles less than 0.2 millimeters in diameter and scatter them aloft as dust or haze.
Saltation is downwind movement of particles in a series of jumps or skips. Saltation normally lifts sand-size particles no more than one centimeter above the ground, and proceeds at one-half to one-third the speed of the wind. A saltating grain may hit other grains that jump up to continue the saltation. It may also hit larger grains that are too heavy to hop, but that slowly creep forward as they are pushed by saltating grains. Surface creep accounts for as much as 25 percent of grain movement in a desert.
Eolian turbidity currents are better known as dust storms. Air over deserts is cooled significantly when rain passes through it. This cooler and denser air sinks toward the desert surface. When it reaches the ground, the air is deflected forward and sweeps up surface debris in its turbulence as a dust storm. Crops, people, villages, and possibly even climates are affected by dust storms.
Most of the dust carried by dust storms is in the form of silt-size particles. Deposits of this windblown silt are known as loess. The thickest known deposit of loess, 335 meters, is on the Loess Plateau in China. In Europe and in the Americas, accumulations of loess are generally from 20 to 30 meters thick.
Small whirlwinds, called dust devils, are common in arid lands and are thought to be related to very intense local heating of the air that results in instabilities of the air mass. Dust devils may be as much as one kilometer high.
Wind-deposited materials hold clues to past as well as to present wind directions and intensities. These features help us understand the present climate and the forces that molded it. Wind deposited sand bodies occur as sand sheets, ripples, and dunes.
Sand sheets are flat, gently undulating sandy plots of sand surfaced by grains that may be too large for saltation. They form approximately 40 percent of eolian depositional surfaces. The Selima Sand Sheet, which occupies 60,000 square kilometers in southern Egypt and northern Sudan, is one of the Earth's largest sand sheets.
The Selima is absolutely flat in some places; in others, active dunes move over its surface. Wind blowing on a sand surface ripples the surface into crests and troughs whose long axes are perpendicular to the wind direction. The average length of jumps during saltation corresponds to the wavelength, or distance between adjacent crests, of the ripples. In ripples, the coarsest materials collect at the crests. This distinguishes small ripples from dunes, where the coarsest materials are generally in the troughs.
Accumulations of sediment blown by the wind into a mound or ridge, dunes have gentle upwind slopes on the wind-facing side. The downwind portion of the dune, the lee slope, is commonly a steep avalanche slope referred to as a slipface. Dunes may have more than one slipface. The minimum height of a slipface is about 30 centimeters.
Sand grains move up the dune's gentle upwind slope by saltation and creep. When particles at the brink of the dune exceed the angle of repose, they spill over in a tiny landslide or avalanche that reforms the slipface. As the avalanching continues, the dune moves in the direction of the wind.
A worldwide inventory of deserts has been developed using images from satellites and from space and aerial photography. It defines five basic types of dunes: crescentic, linear, star, dome, and parabolic.
The most common dune form on Earth and on Mars is the crescentic. Crescent-shaped mounds generally are wider than long. The slipface is on the dune's concave side. These dunes form under winds that blow from one direction, and they also are known as barchans, or transverse dunes.
Some types of crescentic dunes move faster over desert surfaces than any other type of dune. A group of dunes moved more than 100 meters per year between 1954 and 1959 in China's Ningxia Province; similar rates have been recorded in the Western Desert of Egypt. The largest crescentic dunes on Earth, with mean crest-to-crest widths of more than 3 kilometers, are in China's Taklimakan Desert.
Straight or slightly sinuous sand ridges typically much longer than they are wide are known as linear dunes. They may be more than 160 kilometers long. Linear dunes may occur as isolated ridges, but they generally form sets of parallel ridges separated by miles of sand, gravel, or rocky interdune corridors. Some linear dunes merge to form Y-shaped compound dunes. Many form in bidirectional wind regimes. The long axes of these dunes extend in the resultant direction of sand movement.
Radially symmetrical, star dunes are pyramidal sand mounds with slipfaces on three or more arms that radiate from the high center of the mound. They tend to accumulate in areas with multi-directional wind regimes. Star dunes grow upward rather than laterally. They dominate the Grand Erg Oriental of the Sahara. In other deserts, they occur around the margins of the sand seas, particularly near topographic barriers. In the southeast Badain Jaran Desert of China, the star dunes are up to 500 meters tall and may be the tallest dunes on Earth.
Oval or circular mounds that generally lack a slipface, dome dunes are rare and occur at the far upwind margins of sand seas. U-shaped mounds of sand with convex noses trailed by elongated arms are parabolic dunes. Sometimes these dunes are called U-shaped, blowout, or hairpin dunes, and they are well known in coastal deserts. Unlike crescentic dunes, their crests point upwind.
The elongated arms of parabolic dunes follow rather than lead because they have been fixed by vegetation, while the bulk of the sand in the dune migrates forward. The longest known parabolic dune has a trailing arm 12 kilometers long.
Occurring wherever winds periodically reverse direction, reversing dunes are varieties of any of the above types. These dunes typically have major and minor slipfaces oriented in opposite directions.
All these dune types may occur in three forms: simple, compound, and complex. Simple dunes are basic forms with a minimum number of slipfaces that define the geometric type. Compound dunes are large dunes on which smaller dunes of similar type and slipface orientation are superimposed, and complex dunes are combinations of two or more dune types. A crescentic dune with a star dune superimposed on its crest is the most common complex dune.
Simple dunes represent a wind regime that has not changed in intensity or direction since the formation of the dune, while compound and complex dunes suggest that the intensity and direction of the wind has changed.