The Mandrill

 Africa, Mammals, Tropical Forests  No Responses »
Nov 112009
 
photo provided courtesy of tibchris on Flickr Creative CommonsHome – Western Africa
Habitat – tropical forest floor
Niche – large omnivore
Favorite Food – fruit
Length – up to 3 feet
Weight – up to 80 pounds
Status – Vulnerable to Extinction
Threats – hunting, habitat destruction









The rainforests of Central Africa have long been known as dark, forbidding places. Joseph Conrad’s “Heart of Darkness” was set in this otherworldly realm of dense vegetation and hidden dangers. A cryptid named Mokele-Mbembe reputedly lurks in the swamps of the Congo Basin, a lost relic from a distant time in the past. It is a land that is both massive and claustrophobic, a mix of enormous trees with thick underbrush. Many animals blend in among the foliage, but there is one animal that wants to be seent,  making its statement with bright, striking coloration under the trees.

Few animals of the Africa boast such unmistakable features as the mandrill. Sky-blue cheeks taper into its bright red nose sitting over a golden beard. The gaudy coloration of the males is their asset in the mating season, where they attempt to outlook and outdo other males in the quest for females, who are 1/3 the size. Pound for pound, male mandrills are the largest monkeys in the world. Unlike monkeys that dwell exclusively in trees, the mandrill’s legs are of equal length, perfectly adapted for running on all fours on the ground like baboons. However, a troop of mandrills will seek safety in the trees when night falls. This adaptation is especially important in a land where formidable predators hunt at night.

Mandrills are omnivorous and spend most of the day foraging on the forest floor for fruit, seeds, insects, fungi, roots,  and the occasional small animal. They live in groups called “troops” of about 20 individuals, with some large troops reaching as many as 250. Like baboons, Mandrill society is based around a hierarchy with the dominant male at the top. This male earns the right to mate with the females of the group until another male challenges his dominance. The size difference between male and female mandrills is partly explained through this hierarchy. Generally, males of mammal species that mate with many different females show a much greater size difference than those of species that pair for life.

Socializing helps bind mandrill troops together, and grooming is the most important social activity. Members of the troop will take turns picking insects and parastites from the backs of others when they are resting. Also, members will communicate with each other through grunts. These vocalizations help the group to be alerted of dangers and signal when to move on to a new area of forest. The troops move over great distances and will readily defend their territory against unwelcome outsiders. Males attempt to frighten enemies by “yawning” wide, brandishing their two and a half inch long incisors. If the sight of this alone is not enough to deter a foe, the mandrill will rush forward, barking and grunting loudly to scare it off.

Mandrills are rapidly disappearing in the forests of Cameroon and Gabon they have called home for thousands of years. Increased logging and poaching of these animals has cut their numbers significantly. Once common across the rainforests, mandrills are now vulnerable to extinction.

 Posted by at 10:21 am  Tagged with:

The Atacama Desert of South America

 Deserts, South America  2 Responses »
Nov 072009
 
photo provided courtesy of Phillie Casablanca on Flickr Creative CommonsLocation – Peru and Chile
Annual Rainfall – at most,  1mm per year
Age – over 20 million years









Deserts are by definition the driest places on earth. Since water is so essential to life on Earth, deserts are tough places for organisms to carve out a niche, and the driest desert on earth is without parallel on the scale of harsh environments. The Atacama desert of South America receives such a negligible amount of rain that it’s difficult to even detect when it does fall. Indeed, the recorded average rainfall in this bone-dry desert was a mere 0.02 inches over 30 years. That’s as dry as it gets on planet Earth.

The Atacama Desert, like the Namib Desert and Australian Desert, lies adjacent to a coastline, stretching from Peru in the North to central Chile in the south. This narrow desert is bordered on the other side by the massive Andes Mountains, a spine of peaks that divides the entire continent of South America. Both of these factors, ocean and mountain, create the conditions that make the Atacama Desert so arid.

Ocean currents form half of the equation. The current that runs along the western coast of South America, the Humboldt Current, carries cold water from Antarctica northward. This water chills the surface of the Pacific, limiting the amount of water that evaporates into rain-forming clouds. Instead, a dense fog called the camanchaca, and thin, whispy stratus clouds are produced. Neither of these produce rain for Western South America south of Peru.

The second factor that limits rainfall in the Atacama Desert is the Andes Mountain chain. Like the Himalayas limiting rainfall in the Gobi Desert of Asia, the Andes form a barrier to any moisture coming from the Amazon River basin. Clouds are pushed up the slopes of these great mountains and deposit their rain on the side facing the East. Wedged between these two limiting factors  – cold ocean currents and high mountains – the Atacama is lucky to receive any rainfall at all. To make matters worse, the majority of the desert lies in an inland depression, that blocks access to the moist fogs coming off the Pacific. These conditions have remained relatively unchanged for millions of years, and in addition to being the driest desert on earth, the Atacama desert is also one of the oldest.

photo provided courtesy of 22BB on Flickr Creative CommonsWhat life does exist does so primarily around what are called “lomas,” areas of higher elevation that receive some of the moisture from the camanchacas fog coming off the ocean. Very few plants can survive in the gaps between the lomas, and as a result, food chains do not form. Some regions of the Atacama desert are completely devoid of life. Among the hardy plants that inhabit the region are more than 60 species of cactus, influding 25 species unique to the region. A number of bat and bird species also live along the lomas. Most mammal species are confined to the lomas and on the foothills of the Andes, including the guanaco, a small relative of llamas.

Human settlement in the Atacama Desert is limited to areas that can obtain water. To the north, small villages crowd around rivers and mining operations. Closer to the coast, residents stretch large nets to catch the fog as it comes off the Pacific Ocean. The moisture condenses on the nets and then drips into trays and pipes that collect the drinking water in large reservoirs. Because of the overuse and contamination of rivers, this condensor method of capturing water is the only means of life for many people living in the region.

The Atacama Desert is a land of extremes, all of which tell a fascinating story of the way earth’s geosystems interact to produce a final product.

 Posted by at 11:36 am

The Bullet Ant

 Invertebrates, South America, Tropical Forests  No Responses »
Nov 072009
 
photo provided courtesy of Emills1 on Flickr Creative CommonsHome - Amazon River Basin
Habitat – tropical forest, at the base of trees
Niche – predatory insect
Favorite Food – other insects
Length – one inch
Notable Feature – their stings are described as the most painful on earth



















Imagine pain 30 times worse than a bee sting. It is a pain described as walking across a bed of hot coals with a rusted nail inches deep in your sole. It’s fearsome, intense, blackout-inducing pain that can nag a victim for a day or longer as the venom courses through muscles. In fact, this particular insect’s sting is so powerful that it has been compared to being shot with a bullet.

The South American bullet ants are among the largest ants in the world, reaching nearly an inch in length. They inhabit tropical rainforests of Central and South America, ranging from Nicaragua down into the Amazon River Basin, where they like to roam about the trunks of trees in search of food. And as their name implies, they have a fearsome reputation.

Unlike their more social ant cousins, bullet ants are loners in the forests they inhabit, even though they live together in a nest. They are hostile to other bullet ants that they don’t recognize from their nest and will fight to the death. On the other hand, contact with members of the same nest will cause a temporary suspension of the loner lifestyle. If they happen to run into a familiar ant, they will communicate and sometimes pass food back and forth, but that is the extent of their social behavior. For the most part, bullet ants are looking out for number one. Instead of leaving a scent trail to tell other ants about a source of food, these solitary insects will exploit the meal themselves. In addition to feeding on insects, they also have a fondness for nectar and are often seen carrying a droplet of the sweet liquid in their mandibles.

Bullet ants are known and feared for their terrifying stings. Their sting is primarily for defense since most of the insects that the bullet ant eats are already dead. It’s classified as the most painful sting of any insect, beating out even that of the intimidating tarantula hawk wasp. The secret to the pain is in the cocktail of neurotoxins contained in the ant’s venom. The stinger pierces skin and a bulb at its base injects the venom into the wound, causing the cycle of pain as the toxins enter the bloodstream.

Though it seems insane to actively seek the stings of bullet ants, some South American tribes actually use the stings as tests of manhood. The Satere-Mawe people of Brazil are one such tribe. In preparation for the ceremony, bullet ants are collected from the forest and subdued, then woven into large mitts made of leaves. The young men undergoing the right of passage must then place these mitts on their hands and allow the ants to awaken from their stupor. As the enraged ants feverishly try to escape, they sting the hands mercilessly. The custom varies from tribe to tribe, but often boys who are seeking manhood must endure this ordeal without screaming – a tall order for someone under the sensation of being burned alive. And some tribes require that a man pass through this rite not once, but up to 20 times.




 Posted by at 10:29 am  Tagged with:

The Fennec Fox

 Africa, Asia, Deserts, Mammals  No Responses »
Nov 072009
 
photo provided courtesy of abeams on Flickr Creative CommonsHome – Northern Africa and the Arabian Peninsula
Habitat – Desert
Niche – small carnivore
Favorite Food – lizards
Length – up to 28 inches, nose to tail tip
Weight – up to 3 pounds
Status – Unconfirmed
Threats – trapping for fur and for pet trade















The Sahara desert is a land of murderous extremes. Daytime temperatures can spike to 120 degrees Fahrenheit during the day and below freezing in the dead of night. A cracked landscape of barren rocks, rolling dunes of sand, and very sparse vegetation, the Sahara is not a place where life can have an easy go of it. Most mammals cannot survive in deserts because of the harsh conditions and unavailability of water, but one little mammal has bucked the trend for millenia across the sandy wastes.

The fennec fox is the world’s smallest fox. A full grown adult only weighs in at three pounds, much lighter than a house cat. It inhabits the sandy regions of North Africa and the Arabian Peninsula, and is well-adapted to life in the desert. It has fur on the soles of its feet that serves as a buffer between the fox’s body and the burning hot sand of the Sahara, and its giant ears are packed with blood vessels that help to radiate heat away from the body to keep cool. Its size is also an advantage, allowing it to fit into tight spaces and survive on less food and water than larger mammals need.

The fennec fox is also nocturnal, retreating from the sun’s menacing rays during the day into underground burrows until daylight wanes and the temperature dips to a level more suitable for hunting. As the moon rises over the desert, the fennec fox will leave the safety of its den to hunt the sands and rocky crevices for small animals like lizards and insects. It obtains nearly all of its water from the prey that it consumes, so this little fox can live in extremely arid environments where larger animals would most certainly perish.

Most foxes are solitary, but the fennec foxes will often gather in groups of up to 10 individuals. Each member of the group digs a den several yards long into the ground to rear its young and escape larger predators. Females give birth to litters of between 2 and 5 pups and will remain with them in the den for about three months. Fennec foxes reach maturity quickly, becoming fully grown in less than a year, which is yet another adaptation for surviving in a harsh land.

Despite its hardiness, the fennec fox is becoming increasingly rare, especially across the Arabian peninsula, where hunting for its pelts and trapping the young for pets have cut its numbers. There is still much to learn about this tiny dog of the desert. Hopefully it will be around long enough to answer some of the many riddles about its existence.

 Posted by at 8:41 am  Tagged with:

The Siamang

 Asia, Mammals, Tropical Forests  No Responses »
Nov 062009
 
photo provided courtesy of jimbowen0306 on Flickr Creative CommonsHome – Southeast Asia
Habitat – tropical forest
Niche – large omnivore (primarily herbivore)
Favorite Food – leaves
Height – up to 5 feet tall
Weight – up to 33 pounds
Status – Vulnerable to Extinction
Threats – habitat loss, poaching

















It’s morning in the jungles of the Malay Peninsula in Southeast Asia. Among the thousands of animal calls fighting for ear space in the dense forests, one stands out among the rest. Indeed, this animal’s deafening call would drown out even the roar of the African lion if put to the test. Able to be heard for over two miles through dense rainforest, the call of the siamang is the loudest of any land mammal on earth.

The siamang is a member of the gibbon family, a group of small, tree-dwelling apes that are known for their spectacular leaps and unrivaled agility among the dense upper canopy of the Asian rainforests. Swinging through the trees with a 5-foot arm span, the stocky, broad-chested siamang is the largest gibbon. These shaggy black apes live in the rainforests of Malaysia, Thailand, and Sumatra, sharing their range with a number of other gibbon species in the treetops.

The most striking feature of the siamang is the expandable flap of stretchy skin on its throat. The skin can be inflated the size of the animal’s entire head and acts as a resonator chamber, amplifying the piercing calls of the ape to ward off intruders and attract mates. The noisesome calls are primarily used to frighten other siamangs that have stumbled into a family’s territory, which can range up to 115 acres.

photo provided courtesy of Lara604 on Flickr Creative CommonsLike other gibbons and great apes, siamangs are social animals, forming small groups of around 5 animals. These family units are very cohesive, and a family member will rarely venture farther than 100 feet from its kin. As with other apes, grooming is the most important social bonding activity with siamangs. However, social interaction between the family unit is kept to a minimum, leaving most of the day open for eating and resting. Leaves are the siamang’s primary food, forming over half its diet. Fruit and insects form the other half, with some regional variation. Half of the siamang’s waking period from dawn until dusk is spent reasting in the trees, taking short siestas in between foragings.

Siamangs are monogamous, meaning they only mate with one partner during the 2-3 year mating cycle, and the mating pair remains together for life. As is the case with other monogamous mammals, there is very little difference between the sexes in terms of body size. Siamangs show an unusual amount of paternal care for a mammal, and the fathers take over care of the infant after about a year. Indeed, the adult male siamang is responsible for a juvenile’s increasing independence on its journey towards adulthood.

After about eight years of family care, the sexually mature siamang is eased out of its family unit and must strike out on its own. Males then begin a period of wandering in search of females and will call out into the forest to find a mate necessary to build a new family. In fact, the loud “singing” of siamangs is an important part of forging and maintaining the crucial pair bonds.

As the forests fall in the Malay Peninsula, so do the siamangs. As illegal logging, clearcutting, and palm oil plantations increase, the future of these magnificent apes grows increasingly in doubt. Without the trees to support them, the siamang’s call will go silent.

 Posted by at 2:22 pm  Tagged with:
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