Monday, October 31, 2011

The Vampire Bat

Perhaps no other animal is more closely associated with Halloween than the vampire bat. Whereas most bats feed on fruit or flying insects, vampire bats feed almost exclusively on blood; of the three living species, only the common vampire bat feeds on the blood of mammals, the others only target birds.
Common vampire bats can be found throughout most of South and Central America and Mexico. At less than four inches long and weighing only two ounces, vampire bats aren’t considered scary so much as they are regarded as pests by ranchers, as they frequently target livestock animals.

Vampire bats usually live in colonies of 100 to 1000 individuals. They spend their days sleeping and only leave to feed once total darkness has set in. Though they will target wild mammals and even humans on rare occasions, common vampire bats prefer to feed on domestic horses and cattle.
Vampire bats have good eyesight, but primarily use their hearing and sense of smell to track down prey. Once a host has been found, the bat will either land on it or land near it, choosing to either scramble up the victim or feed on it from the ground. The bat will then use the heat sensors in its nose to locate blood vessels close to the skin’s surface. Once a suitable spot has been found (usually near the rump or neck), the bat will use its razor sharp incisors to make a small wound and lap up blood until it has nearly doubled its weight. Too heavy to fly after its meal, the vampire bat (which is quite agile on the ground) will find a sheltered spot to rest and digest until it can fly again.

Despite its gluttonous feeding habits, the tiny vampire bat never drinks enough blood to endanger a large mammal. In fact, it is common for them to return to the same host to feed every night, even defending it from other hungry vampire bats.

Friday, October 28, 2011

Animal Actor - The Opossum

Opossums are marsupials that carry their young in pouches like kangaroos. The Virginia opossum is the only marsupial found in the United States and Canada. Sometimes incorrectly referred to as “possums”, which are different animals indigenous to Australia, opossums are very adaptable, omnivorous animals that can survive in a variety of climates.
Photo: Cody Pope   
Roughly the size of a house cat, the opossum has a large snout, large canine teeth and feet that are covered in scales called scutes. Their strong tails help them to grip tree branches and other objects, and females have pouches in which to carry their young.

Opossums are primarily nocturnal animals that will roam wherever food and water is available. They will eat almost anything, scavenging human garbage, roadkill and fruits and nuts. They are also known to hunt small animals such as snakes, insects, birds and mice. Ever opportunistic, opossums will sleep in burrows wherever they can find them both above and below ground, but will rarely put much effort into digging a den themselves.

Opossums spend much of their time in trees where they are less vulnerable to predation and use their claws and tails to easily grip branches and tree bark. However, they do often come down to flat ground to forage for food and are thus exposed to predators such as bobcats and dogs. When confronted with a threat the opossum is well known for its ability to “play possum”, tricking the predator into believing it is dead. Far from just an act, this involuntary response causes the animal to fall over; teeth bared, and even secrete a foul smelling fluid from its glands to make it seem less appetizing. Opossums cannot voluntarily wake up from this state and usually do not regain consciousness for 1-4 hours.
Opossum "playing possum"
Baby opossums are only about the size of a honeybee when they are first born and must quickly crawl into their mother’s pouch to survive. Once inside, the baby opossums will wean for 70 to 125 days until they are large enough to emerge and live on their own. Female opossums may give birth to up to 20 offspring at once, but the majority may not even reach her pouch. Although opossums are relatively large mammals, they have an unusually short lifespan of only 2-4 years.

Thursday, October 27, 2011

The Killer Whale - King of the Sea

Though some may think large sharks are the most fearsome animals in the ocean, even predators such as the great white exist below one animal on the food chain; the killer whale. Also known as orcas, killer whales are the largest of all dolphins and are true apex predators, even hunting great white sharks on occasion.
At up to 32 feet long and weighing 15,000lbs, the largest killer whales can equal a city bus in size. If their size isn’t enough of an indicator, orcas can be easily recognized by their black coloring with characteristic white patches above their eyes and on their bellies as well as a massive six foot dorsal fin.

There are a variety of different types of orcas living in every ocean in the world, though there are slight differences in appearance, feeding and social habits depending upon habitat. Some are residents of the same area year-round and form strong family bonds, whereas other types are transient and move from place to place. Most live and travel in groups of anywhere from 2 to 75 depending on type.
As apex predators, killer whales hunt an enormous variety of sea life. Resident killer whales usually prey upon fish and squid, whereas transient orcas eat other marine mammals such as seals, porpoises and other whales almost exclusively. Killer whales may also prey upon large sharks, using their superior intelligence to hold sharks upside down and suffocate them. Much like a pack of wolves, killer whales hunt large prey such as other whales in packs. Interestingly enough, resident killer whales may swim or play with dolphins and porpoises, both prey animals to transient orcas.
Despite their name, wild killer whales have never been responsible for a fatal attack on a human. Their intelligence along with their playful nature seems to suggest that it is easy for orcas to differentiate between humans and their natural prey. However, there have been several attacks by captive killer whales, leading many to condemn the practice of keeping these animals in aquariums. Most killer whales can live well into their thirties in the wild, with some females reaching 90 years of age.

Wednesday, October 26, 2011

Backyard Nature - The Cardinal

If you’re a baseball fan, you’ve no doubt noticed that one of the teams in the World Series this year is the St. Louis Cardinals. Their mascot just happens to be one of the most recognizable songbirds in the world and possibly a year-round resident of your backyard.
Male northern cardinal
The northern cardinal, also known as the common cardinal, is native to the eastern half of the United States, Mexico and parts of Canada. Male northern cardinals are almost completely bright red, a color they maintain year round, and have a black face and thick, orange bill. Females are similar in build but are primarily light brown with bits of red on their wings, tail and head. Both sexes usually measure 8-9 inches long and have a wingspan of under a foot.
Female northern cardinal
Northern cardinals make their homes in forested areas, open fields, thickets and backyards. They have short wings and are not particularly good fliers, so most are residents of the same area all year. As such, they are often the only songbirds you can hear on winter mornings. Northern cardinals primarily feed on seeds or grains and are frequent visitors to backyard bird feeders.

Male cardinals are extremely territorial. They will spend many hours during the day perched at the top of trees singing loudly; they do this to mark the boundaries of their territory. In spring in particular, male cardinals will mistake their reflection in windows or car bumpers as a rival male and will often spend many hours savagely attacking the imaginary intruder. Northern cardinals are one of the few species of songbirds in North America where the female sings. It is believed that they sing to communicate with their mate while in the nest.
Beak to beak feeding
During mating season, which is usually in the spring, males will court females by bringing them seeds and will feed the female beak to beak. Cardinals don’t use the same nest twice, so each spring the female is responsible for building a new one. The male will often assist by bringing her sticks and building materials and the rather complex nest will be constructed in about a week. Most nests are built 1-15 feet above ground either in the fork of a tree or in a thicket or bush.
While cardinals can mate for life, most live little more than a year. Their lack of flying skills combined with the fact that they spend much of their time near or on the ground makes them easy prey for hawks, owls and gray squirrels. Nevertheless, northern cardinals are capable of living for over 15 years.

Tuesday, October 25, 2011

Bush Dogs

Bush dogs, also known as vinegar dogs, are small canids native to many lowland forests throughout South America. Despite an extensive range, bush dogs are quite rare, with the current population estimated to be about 15,000.
Roughly the size of foxes, bush dogs usually weigh 11-18lbs and have short legs and a small snout in proportion to the size of their bodies. They are semi-aquatic and have webbed feet that allow them to swim and dive easily. Like all canids, bush dogs are carnivores. They primarily hunt small rodents, but can bring down much larger animals such as tapirs when hunting in packs.
Bush dogs live in tropical forests or wet savannahs often near a water source. They usually den in a hollow log or abandoned armadillo burrow. The typical bush dog family unit may consist of up to twelve individuals with only one reproducing female. The remaining females in the group help care for pups, usually born in a litter of four. Bush dogs can live for up to 10 years in the wild.

Monday, October 24, 2011

Siberian Tiger Gets Root Canal

Going to the dentist isn’t fun for anyone, and when the patient is a 300lb Siberian tiger, things get a little more complicated.
At the Alaska Zoo last week resident Siberian tiger Kunali had a root canal performed on one of his giant, three inch teeth. Kunali had fractured the tooth several years earlier and veterinarians decided to go ahead with the procedure to prevent the possibility of future infection. The operation on the seven foot cat was made easier due to the donation of a special new hydraulic operating table. Previously these procedures had to be performed in the animal’s exhibits with little space or light.

Kunali was sedated during the operation and is reportedly recovering just fine. According to the dentist, it was the largest tooth he had ever worked on.

Story via.

Friday, October 21, 2011

Emus - Good Fathers

Unlike most species of birds, young emus are cared for and raised by their fathers. After laying their eggs, female emus immediately leave the nest to mate with another male, leaving the expecting father in charge of incubation. For 8 weeks after the eggs have been laid the male will cease from eating or drinking and survive only on stored body fat. He will only stand up about 10 times per day to turn them. Once hatched, the chicks will continue to be cared for by their father until roughly 9 months of age.
Wild Emus only exist in Australia, where they are quite common in wooded areas or locations with reliable water sources. They are the second largest extant bird in the word, with only the ostrich being larger. Emus are brown in color and can stand up to six and a half feet tall, weighing anywhere from 40 to 120lbs. Although they do have small wings emus are not capable of flight. Rather, they flap their wings when running to stabilize their bodies at the 30mph+ speeds they can attain.
Emu Chick
Emus are diurnal, meaning they are active during the day. Their diet includes a large variety of plants, grains and insects, all depending on habitat or seasonal availability. Emus also eat a lot of rocks. They do this because pebbles and stones help them digest plant material. An emu will usually have over a pound of pebbles in its stomach at any one time. Emus can go several days without water, and weeks without food, but will indulge frequently in both if a reliable source is present.

Thursday, October 20, 2011

The Bighorn Sheep

Recognized by their large curved horns, bighorn sheep have become one of the most recognizable symbols of the mountainous western United States. This powerful mammal is believed to have entered North America using the land bridge that once connected the continent with Asia. Prior to the 1900s it is estimated that bighorn sheep numbered in the millions, but hunting, competition from domestic sheep and habitat loss had reduced their population to only a few thousand by the beginning of the 20th century. Conservation efforts led by the Boy Scouts of America began in the 1930’s and have done much to restore the distribution of this regal animal.

Bighorn sheep are easily differentiated from their domestic cousins. They have a brown coat with white underbelly and rump, a very short tail and large horns; these horns can weigh up to 30lbs on males, and are significantly smaller and less curved on females. Males are larger and usually weigh between 125-300lbs, though some subspecies in mountainous regions can weigh nearly 500lbs. Females on the other hand weigh up to 200lbs, with some as small as 75lbs.
The range of bighorn sheep stretches from the Rocky Mountains in Canada and the United States south to parts of Texas, New Mexico, Arizona, California, and Northern Mexico. Bighorn sheep usually live on and around mountain slopes, foothills and high meadows. Their summers are usually spent at up to 8500 feet in the mountains, where their superior climbing ability allows them to avoid predators such as wolves and mountain lions. When winter comes, the bighorns will descend to meadows at lower altitudes, as they are not equipped to travel efficiently through deep snow.
Bighorn sheep have a very well-known mating ritual in which mature rams will clash horns, running at each other at up to 20mph. These contests, which are used to establish dominance, can last up to 20 hours, with the winner usually being able to mate with more or preferable females. Ewes will give birth to their lambs along ledges, cliffs, or any other area that is difficult for a predator to access. Newborn lambs are able to walk within a few hours and will depend on their mother for milk for the first 4-6 months of life. At 2-4 years old, young rams finally leave their mothers and join a flock of other rams; ewes will likely stay in the same flock as their mother for life.

Wednesday, October 19, 2011

Most Deadly - The Golden Poison Frog

The golden poison frog is the most lethal of the poison dart frogs and is considered the most poisonous animal on earth. The entire family of poison dart frogs gets their names from indigenous tribes in the South American rainforests that use the toxins secreted by these frogs to tip darts and arrows for hunting. It is estimated that the golden poison frog contains enough poison to kill 10-20 humans and up to 10,000 mice. The frogs do not actually manufacture this toxin. Rather it is ingested by the frogs when they eat certain types of native insects and is secreted through their skin glands. Golden poison frogs do not use their toxin to hunt; it is only for defensive purposes.
Photo: Wilfried Berns
Golden poison frogs are among the largest of the poison dart frogs and can reach a length of over two inches as adults. They are very brightly colored and are usually mint green, yellow or orange. The purpose of this bright coloring is to warn potential predators of the frog’s toxicity, as almost any animal that consumes it will die immediately.

The golden poison frog is diurnal, meaning it is active during the day. It hunts insects using its long tongue to strike and pull the prey to its mouth, a technique which demonstrates a high degree of intelligence. As these frogs have virtually no natural predators, they make no attempt to hide from larger animals and seem to be aware that they are not threatened by predators. They are social animals, and live in groups of 4-7 individuals. Being as they are immune to their own poison, these frogs interact with each other frequently.
In contrast to their incredible toxicity in the wild, golden poison frogs raised in captivity are harmless. Being as their poison is supplied by eating insects that only exist in the South American rainforest, they never become poisonous when fed garden-variety flies and crickets from birth. Wild-born poison dart frogs that live in captivity also eventually lose their toxicity, but it may take several years for this to happen.

Monday, October 17, 2011

The Osprey - Fish Hunter

The osprey is a large bird of prey that can be found on every continent except Antarctica. It is one of the most wide-ranging species of bird in the world and is uniquely separate from sea eagles such as the bald eagle.

Ospreys are very large raptors with an average body length of over two feet and a wingspan of up to six feet. Females are slightly stouter in the body than males and have wider wings, but both weigh between 2-5lbs. Ospreys are dark brown to grey on the top of their bodies with a predominantly white underside. They have white feet with black talons and can be easily identified in flight by the four finger-like feathers on their wingtips.
As they feed exclusively on fish, ospreys almost always live near water. They are only permanent residents in the subtropical northern hemisphere, but can be found as far north as Alaska during the summer and as far south as Argentina during the northern winter.

The osprey has developed into a very specialized fish hunter and has incredible eyesight to spot underwater prey from high altitudes. Once a fish is spotted, the osprey will hover momentarily before making its dive, snatching the fish out of water with rough talons specifically designed to grasp slippery prey. The osprey will usually carry the fish back to its nest held head first to maximize aerodynamics. More rarely ospreys will hunt small mammals and reptiles if necessary. A fully-grown adult osprey is considered an apex predator in most habitats and does not face a threat from other birds. However, from time to time larger bald eagles have been known to steal the smaller osprey’s kills.
Ospreys will readily nest on man-made structures. Special osprey nesting platforms have been constructed in many locations to help reestablish the species in areas where it is no longer common. The oldest osprey on record lived to be over 30 years old.

Friday, October 14, 2011

Hares & Jackrabbits

Many people are not aware that jackrabbits and hares are from a different genus than rabbits. Though their long ears and body appearance is similar, jackrabbits and hares usually have longer, more slender bodies and more powerful legs.
All hares and jackrabbits are members of the Lepus genus; most North and South American varieties are referred to as jackrabbits, with hare being the common name in the rest of the world.

Whereas most rabbits live and give birth in underground burrows, jackrabbits and hares nest in simple shallow depressions above-ground. They give birth to fully furred young that are able to survive on their own at a very young age.
There are 32 species of hares and jackrabbits with numerous subspecies of most. They can be found in a variety of habitats from hot deserts to forested mountain regions. Like rabbits, hares eat a large variety of plants, shrubs, grasses and small trees. All members of the Lepus genus play an important role in their respective ecosystems as a food source. For instance, the black-tailed jackrabbit, common to most of western North America, is the primary prey of bobcats, coyotes, foxes and large raptors.

Not that hunting the jackrabbit is an easy task; some can run at speeds of over 45 miles per hour!

Thursday, October 13, 2011

The Addax - Desert Antelope

The addax is a species of antelope that is native to the Sahara desert. Sometimes referred to as the screwhorn antelope, they are critically endangered in the wild due to unregulated hunting.
Addaxes are around three feet tall at the shoulder and weigh 130 to 260lbs. Their most distinctive identifying features are the long, spiraling horns that occur on both sexes. These horns can reach nearly four feet long on males. The coloring of their coats varies by season; grey in the winter and nearly completely white in the summer.

Addaxes are ideally suited to living in a harsh desert environment. They are able to satisfy all of their hydration requirements with just the native grasses they eat and do not need to drink water to survive; however they will certainly drink from any water sources that are available.
Addaxes live in herds of two to fifty animals, usually led by a dominant older male. They are nomadic animals and will wander wherever food is available. They can be predated by lions, leopards and hyenas. It is estimated that there are fewer than 200 addaxes left in the wild, with an additional 800 living in captive herds.

Wednesday, October 12, 2011

Scorpions - Glowing Predators

There’s no doubt about it, scorpions are some of the most fearsome looking animals on the planet. They have giant stingers, powerful pinschers and even glow in the dark under U.V. light! 

There are over 1700 species of these sinister looking arachnids, and they live on every continent in the world except Antarctica. Though justifiably feared for their sting, fewer than 40 species have venom strong enough to be fatal to humans.
Photo: Chris Huh
Though usually thought of as desert-dwellers, scorpions can be found in almost every habitat on earth. They prefer areas where soil or rock outcroppings allow them to burrow or hide from the sun but can also live in trees or even on high-altitude mountaintops permanently covered in snow. 

Scorpions are pure carnivores that subsist mainly on insects, spiders and other scorpions. However, some larger species feed on lizards, snakes and small rodents as well. Prey is usually caught with the scorpion’s pincers and then subdued with a venomous sting. One unique feature that allows scorpions to survive when food is scarce is their ability to slow their metabolism at will. By doing this, scorpions can survive on as little as one insect a year if necessary. However, unlike hibernating animals scorpions are still capable of quickly returning their metabolic rates to normal if a prey opportunity presents itself. 

Scorpions are usually quite solitary and only interact with each other to mate (or eat) one another. Unlike most arachnids, scorpions give birth to live young. Litters can range in size from two to one hundred young, called scorplings. When born, scorplings look like perfectly proportioned miniature versions of their parents. They will ride on their mother’s back until they have molted, as up to that time their exoskeletons are soft and unable to protect them from attack. Scorpions molt five to seven times before they reach maturity and depending on species can live anywhere from four to thirty years.

Tuesday, October 11, 2011

The Shoebill - Missing Link?

The shoebill is a large, prehistoric-looking bird native to the swamps of tropical east Africa. Though originally thought to be more closely related to storks, scientists have now placed the shoebill in the same order as pelicans and consider it one of the “missing links” that connects pelicans and storks. 

Shoebills are easily recognized by their massive, foot-long beaks with a sharp barb on the end. The bird’s name is derived from this beak resembling a shoe.
The shoebill is a very large bird. Adults can stand five feet tall, weigh over 15lbs and have wingspans of ten feet. Although they do have strong wings, shoebills require a lot of open space to take off, something their swampy habitat does not provide. Because of this they can be reluctant fliers, even occasionally nesting on the ground.

Shoebills feed on a variety of fish, baby crocodiles and small mammals. They hunt by waiting motionless then ambushing their prey from the water with their powerful beaks.

The current estimated population of shoebills is between five and eight thousand individuals, with the bulk living in Sudan. Habitat loss and hunting have led to the shoebill being classified as vulnerable.

Monday, October 10, 2011

The Columbian Exchange

Christopher Columbus first arrived in the Americas on October 12th, 1492. Columbus Day is celebrated in the United States today in memory of that event and how it undoubtedly changed the world forever. One of the biggest impacts his arrival had was due to the number of animals and crops introduced to the New World; this is known as the Columbian Exchange.

From a biological perspective, both North and South America were very different places before European settlers arrived. With the exception of alpacas and llamas there were virtually no large animals in the Americas suitable for domestication. The Europeans introduced cattle, sheep, goats and of course, horses; all animals considered vital to both the history and modern economies of the Americas.
The new presence of these animals, all either nonnative or extinct in the Americas for thousands of years, changed life for native peoples significantly; large livestock animals allowed farming cultures to become ranching cultures, and the horse allowed native tribes the nomadic freedom to hunt large animals such as bison.
With trade between Europe and the Americas open for the first time, some New World animals were introduced to Europe as well. Turkeys, llamas, alpacas and guinea pigs were all introduced to Europe and Asia, where they are now common.
Though there is some debate over who actually “discovered” the New World, there is little doubt that the animals introduced during the Columbian Exchange affected it in a very profound way.

Thursday, October 6, 2011

Sand Cats - Desert-Dwelling Felines

The sand cat is one of the smallest members of Felis genus, which includes domestic cats and wildcats. Weighing between three and eight pounds, sand cats somewhat resemble small domestic cats but have wider heads and larger ears.
Sand cats can only be found in the Arabian Desert, the Sahara, and hot and dry areas of Iran and Pakistan. They spend their days in underground burrows, coming out after dusk to hunt small rodents, birds, lizards and insects. The sand cat gets all of the water it requires to survive from its prey and has no need to live close to a water source.

Unlike most felines, sand cats are not territorial and may even switch burrows with other sand cats on occasion. They live extremely solitary lives, only socializing with each other during the mating season. 
 Sand cats are known to be docile and unafraid of humans. Hunting of these cats is prohibited in many areas of their range, as their population is declining. However, they do still face threats from humans in unprotected areas as well as predation by wolves, snakes and large birds of prey. The sand cat’s average lifespan in the wild is unknown, but they can live up to 13 years in captivity. 

Wednesday, October 5, 2011

Meet the Kakapo

The kakapo may be one of the most unique birds in the world, and with only 131 living individuals left, it is certainly the rarest.
Kakapos are flightless parrots native to New Zealand. Mature adults can weigh over 9lbs, making them the heaviest parrots in the world. They are also extremely long-lived, with an average life span of 90-120 years.
Kakapos were common to New Zealand prior to colonization. Like the kiwi, it is believed that the kakapo lost its ability to fly due to the isolation of its habitat and lack of any native predators. When settlers began to arrive in New Zealand they brought along nonnative animals such as cats, dogs, weasels and rats. Kakapos, slow-moving and unequipped with any way of escaping these animals became easy prey, and were nearly wiped out by the beginning of the twentieth century.
In recent decades, all remaining kakapos have been transferred from mainland New Zealand to predator-free outlying islands as part of an intense recovery plan. Nearly all of the remaining 131 birds are well-known and individually named by researchers and zoologists.

For more information on this amazing bird you can visit the Kakapo Recovery website.

Tuesday, October 4, 2011

The Picassofish - Swimming Art

One of the most striking fish in the world is the Picassofish, also known as the lagoon triggerfish or the Jamal. Its striking splashes of color and high-set eyes are unmistakable and make this species a popular saltwater aquarium resident.

The range of the Picassofish consists of the many reefs near Hawaii, the Philippines and the coast of China. Picassofish are usually less than a foot long and feed on a variety of small fish and invertebrates. Like all triggerfish, the Picassofish has the ability to lock itself into crevices using the three spines on its dorsal fin. Once these spines are erected the fish cannot be dislodged without pressing the third “trigger” spine.
Picassofish can be quite aggressive towards anything that invades their territory, including divers attracted by their beautiful coloration. However, the small size of the Picassofish prevents it from being dangerous to humans.

Monday, October 3, 2011

Binturongs - Asian Bearcats

At first glance the binturong might be mistaken for a lot of other animals. Its head looks like it belongs on a cat or perhaps an otter, while its body looks like somewhat of a cross between a wolverine, a bear and a sloth.
The binturong, sometimes referred to as the Asian bearcat, is actually a member of the Viverridae family; home to animals such as civets and genets. The origins of the binturong’s name are no longer known, as the language spoken by the locals who originally coined it is now extinct.
Binturongs are native the rainforest canopy of Southeast Asia in countries such as Malaysia, the Philippines, Thailand and Vietnam. They are omnivorous and eat a variety of different fruits, leaves, lizards and carrion. Their strong claws and long prehensile tails allow them to easily traverse trees and even walk down tree trunks head first!

One interesting aspect of the binturong is its smell. Like many animals, it has scent glands that are used to mark territory. However, the binturong’s particular scent is similar to hot, buttered popcorn!

Habitat loss and the binturong’s popularity as a pet are current threats to its livelihood in the wild.