American Beaver - Castor canadensis

The American beaver (Castor canadensis) is one of two living species of beavers that belong to the Family Castoridae—the other species of beaver is the Eurasian beaver (Castor fiber). The American beaver can reach weights in excess of 30 kg, making it the world's second largest rodent. Only the capybara of South America is larger.

American beavers are stocky and have a compact body and short legs. Beavers are aquatic rodents and have a number of adaptations that make them adept swimmers including webbed feet and a broad, flat tail covered with scales. Beavers have a pair of glands located at the base of their tail. These glands, called castor glands, secrete an oil that has a distinct musk odor and the beaver uses the oil to mark its territory and to waterproof its fur.

Beavers have very large teeth in proportion to their skull. Their teeth and are coated with a tough enamel that is orange to chestnut brown in color. Beavers' teeth grow continuously and are warn away and sharped as the beaver chews through trees and bark. Beavers have strong chewing muscles and singificant biting strength.

Bar-headed Goose - Anser indicus

The bar-headed goose (Anser indicus) gets its common named from the two bars of brownish-black colored feathers that wrap around the back of its head. This goose has a light grey body, white on its face and neck, orange legs, and bill. Its feet are webbed and it has broad wings. Adults, on average, grow to lengths of 30in and weights of 4lb-6.5lb.

Female bar-headed geese lay 4-6 white eggs per clutch, the eggs require about 27 days to incubate. In the wild, bar-headed geese breed in Central Asia (southeast Russia, northern India and western China) and migrates over the Himalayas to over-winter in India and northern Burma.

Scientists Re-evaluate 500-Million-Year-Old Fossils

Sometimes when you stare at something long enough—a cloud formation or a Rorschach ink blot, for example—it can suddenly take on an entirely different appearance. Such a visual shift can take place even for those with well-trained eyes, such as scientists who spend significant amounts of time staring at fossils. And when fossils are viewed differently, the resulting re-interpretted may have implications that are both fascinating and far-reaching.

It was just such a visual awakening that took place for a team of researchers from Uppsala University who were studying fossils collected from the Burgess Shale. The team, led by Allison Daley and Graham Budd, was particularly interested in a creature known as Hurdia victoria. Hurdia victoria was first described in 1912, but for many years, scientists lacked a clear picture of what Hurdia victoria may have looked like.

Fossil Carnivore Sheds Light on Pinneped Evolution

A small fossil carnivore discovered on Devon Island, in Nunavut, Canada has shed light on an obscure stage in pinneped evolution. Pinnepeds belong to a group of marine carnivores that includes seals, sea lions, and the walrus. Pinnepeds are semi-aquatic mammals with limbs that have been modified into flippers. Pinnepeds are believed to be close cousins to two other groups of carnivores, the Ursidae (bears) and the Mustleoidae (skunks, otters, badgers, and relatives). Although scientists understand a considerable amount about the relationship pinnepeds have to other groups of carnivores, little is know about the terrestrial ancestors of today's pinnepeds.

ew Program Protects Mountain Gorillas' Health

The University of California, Davis and the Mountain Gorilla Veterinary Project have together launched an ambitious and comprehensive program to protect mountain gorillas (Gorilla geringei beringei). The program, called 'One Health', aims to protect the remaining 740 mountain gorillas that inhabit the Virunga Mountains, a crest of mountains that straddles the borders of Uganda, Rwanda, and the Democratic Republic of the Congo in Central Africa.

The One Health program will bring together wildlife veterinarians from UC Davis and experts from the Mountain Gorilla Veterinary Project, a project started in 1986 at the request of the late primatologist Dian Fossey. The two organizations will work together to improve not only the health of mountain gorillas, but also the health of nearby human and livestock populations.

"The collaboration with UC Davis will help improve the health and welfare of the humans and animals living around the gorillas. This in turn acts as a buffer to help prevent disease—the gorillas' leading cause of death—from entering the park and affecting gorilla families." ~Mike Cranfield, UC Davis.

Apart from four young orphans soon to be released into the wild, no mountain gorillas live in captivity. So protecting the wild population from disease is of critical importance. Fortunately, the One Health program has a good head start. During the past decade, conservation efforts have helped to increase mountain gorilla numbers by 17 percent. Anti-poaching measures, habitat protection, and medical programs have all contributed to this success.

Larger Crests Signal Lower Stress in Male Crested Auklets

During the breeding season, male and female crested auklets (Aethia cristatella) grow a distinct group of bristle feathers on the top of their head. Scientists have for some time known that both sexes show a preference for selecting mates with larger crests. Now, a team of researchers from the University of Alaska Fairbanks have discovered that the larger feathers a male crested auklet has, the lower its stress hormones. This suggests that males with larger crests may be better able to cope with the demands of reproduction, foraging, and competition. As a result, they could be better mates than males with smaller crests and higher stress hormones.

Crested auklets are small seabirds that gather to breed in colonies along the coastlines and islands of the Bearing Sea, North Pacific, and Okhotsk Sea. They nest on cliffs, in boulder fields, and on sea-facing talus slopes. Crested auklets are socially monogomous but Hector Douglas, one of the study's lead authors, noted that females will abandon their current mate in favor of a male with a larger crest:

Canaries Sing Well Despite Poor Tutors

The way birds learn to sing is of interest to scientists because it offers clues to understanding how humans learn to talk. Young birds, like children, must hear their parents' vocalizations if they are to develop normal song patterns. Juvenile birds that grow up in the absense of birdsong develop abnormal songs. The same is true of children, if a child grows up in the absense of speech, they develop only the most basic verbal skills.

Researchers Sandra Belzner and Stefan Leitner of the Max Planck Institute for Ornithology recently conducted an experiment to determine just what it is about hearing birdsong that young birds benefit from. They started out by establishing a group of birds that had poor singing skills. The birds in this group were isolated from adult male canaries as they grew up. These canaries developed abnormal vocalizations. When the group had their own young, Belzner and Leitner investigated how the vocalizations of their young developped.

Coastal Sand Dunes

Coastal sand dunes are dynamic but fragile buffer zones of sand and vegetation that form where the following three characteristics can be found:

• large quantities of sand
• persistent wind capable of moving the sand
• suitable locations for sand to accumulate

The process of dune formation begins with a steady on-shore wind capable of moving sand. The wind moves the sand into piles. Eventually the sand pile becomes so steep that the leeward side of the sand pile collapses under its own weight and spills down at an angle that serves to stabilize the dune. Over time, the dune migrates in the direction of the wind, as the wind moves sand up the dune's slope and over the edge.

Komodo Dragons Pack a Venomous Bite

Research reported this week in the Proceedings of the National Academy of Sciences has revealed that Komodo dragons (Varanus komodoensis) deliver a venomous bite to their victims, a fact that makes this already fearsome giant reptile even more formidable.

Komodo dragons are the world's largest species of lizard. Adults can grow to lengths of 3m and weigh as much as 165 kg. Previously, scientists thought the Komodo dragon's saliva was non-venomous and was instead laden with pathogenic bacteria which infected and immobilized their prey. But now a team of scientists led by Bryan Fry of the Australian Venom Research Unit at the University of Melbourne have discovered that Komodo dragons possess a venom gland with ducts that feed into the lizard's teeth. When the Komodo dragon bites its victim, the venom drains through these ducts in their teeth and into the animals wounds.

Humans and Spider Monkeys Exhibit Similar Food Habits

Scientists have discovered that wild spider monkeys have similar eating habits to humans. Now that doesn't mean they dine at fast food restaurants or frequent juice bars, but it turns out that these primates don't try to maximize their daily protein intake when surplus food is available, but they instead regulate their diet so that it remains about the same throughout the seasons and when different foods are available.

It has previously been thought by scientists that human eating habits originated sometime during the Palaeolithic era (between 2.4 MYA – 10,000 YA). But if spider monkeys also share this eating behavior, it could mean that the habit of maintaining a regulated daily protein intake is older than originally thought.

Sea Cliff Habitats

Sea cliffs are high, rocky coasts that plunge down to the sea's edge. These harsh environments are subject to the battering of waves, wind, and salt-laden sea spray. Conditions on a sea cliff vary as you move up the cliff, with waves and sea spray playing larger parts in shaping the communities at the base of a sea cliff while wind, weather, and sun exposure are the driving forces that shape the communities towards the top of a sea cliff.

Sea cliffs provide ideal nesting habitat for many species of sea birds such as gannets, cormorants, kittiwakes, and guillemots. Some cliff-nesting species form large, dense nesting colonies that stretch across the face of the cliff, taking advantage of every inch of available rock.

At the base of the cliff, the pommeling by the surf prohibits all but the most tenacious of animals from surviving there. Mollusks and other invertebrates such as crabs and echinoderms occasionally find shelter behind rocky outcrops or tucked within tiny crevices. The top of the sea cliff is often more forgiving than its base and can be frequented by wildlife from surrounding terrain. Often, the craggy edges at the top of a cliff provide ideal habitat for small mammals, reptiles, and birds.

Dugong - Dugong dugon

Dugongs (Dugong dugon) are marine mammals that grow to lengths of up to three meters and weigh as much as 400 kilograms. Dugongs are also known as 'sea cows' because they feed on sea grass and the roots of aquatic plants in sheltered coastal waters. Dugongs have a fluked tail that enables them to swim. They have front flippers that they use to steer as they swim slowly through the water.

Their head is round and they have small eyes and nostrils at the top of their broad snout. Bristles located on their upper lip help them locate food. Their eyesight is limited but they have keen hearing. Dugongs can live as long as seventy years. They have a low breeding rate and on average females bear a single calf at intervals of 3 to 7 years during their reproductive years.

Dugongs usually feed at night in coastal waters, rarely venturing out into open sea or into estuaries and rivers.