mammals

Lowland gorillas (Gorilla gorilla), photographed at the Bronx Zoo.
A domestic horse (Equus ferus caballus), photographed in suburban New Jersey.
Almost two decades ago vertebrate paleontologist Bruce MacFadden published his monograph Fossil Horses, an instant classic that was as much about new approaches in paleontology as the equids considered in the book. For over a century the family history of horses had been depicted as some of the best, most-accessible evidence for evolution the fossil record had to offer, and MacFadden's book provided an excellent synthesis of what had been discovered. Since the publication of Fossil Horses, however, no other books have appeared to follow-up on what MacFadden presented. Brief nods and short…
Zeff the Amur tiger (Panthera tigris altaica) yawns. Photographed at the Bronx Zoo.
These are rock hyraxes or dassies. They may look like guinea pigs, but they're in an entirely different order of mammals. It's sometimes said that they are the closest living relatives of elephants. However, some scientists would dispute that sirenians - the manatees and dugongs - are more closely related still, with the hyraxes as a more distant outgroup. They're nimble animals, scuttling comfortably across rocky terrain and even climbing trees with relative ease. They can often be spotted basking in the sun to raise their body temperature, not unlike a reptile would. We found this pair in…
A Mexican wolf (Canis lupus baileyi), photographed at the National Zoo.
A female lowland gorilla (Gorilla gorilla), photographed at the Bronx Zoo. A note about "Photo of the Day": I recognize that this daily feature has not been as exciting lately. I often visit zoos, museums, and other places rich in photo ops throughout the year, but during the past several months my opportunities to do so have been limited. I have therefore had to mine my stores for miscellaneous photos from previous trips which I have not posted before, but I am hoping to get back out to take some fresh shots sometime around my birthday at the end of the month. Thank you for your patience.
A pronghorn (Antilocapra americana), photographed on Antelope Island, Utah.
A grizzly bear (the black dot in the middle of the photo) walking near the treeline in Yellowstone's Hayden Valley. The quiet of my evening wildlife watching was suddenly broken by a thick Boston accent. "Oh my gawd! Look! It's a grizz! That's the last animal I needed to see! It's a grizz!" He was right. Lumbering across the valley was a big dark shape that could only be a bear. It was not very close, being little more than a dot moving along the distant treeline, but through the zoom lens of my camera it was just possible to make out the hump that distinguishes black bears from grizzly…
Rokan, the Sumatran tiger (Panthera tigris sumatrae), photographed at the National Zoo in Washington, DC.
A snow leopard (Panthera uncia), photographed at the Bronx Zoo.
The WCS-run Bronx Zoo welcomed four new additions this week; a trio of brown bear cubs from Alaska and an adolescent bear from Montana. All were rescued after their mothers had been killed for becoming too habituated to humans. According to the Bronx Zoo press release: The three brown bear cubs are siblings, born in early 2009 on Baranof Island in southeastern Alaska. The Alaska Department of Fish and Game rescued the orphaned trio and temporarily transferred them to Fortress of the Bear, an education and rescue center in Sitka, Alaska. The young grizzly bear, a male from Glacier National…
Part of a bison herd (Bison bison) walking down the road. Photographed in Yellowstone National Park.
A calf (Bos primigenius taurus), photographed in suburban New Jersey.
A pregnant female elk (Cervus canadensis), photographed in Yellowstone National Park.
Millions of years before humans invented sonar, bats and toothed whales had mastered the biological version of the same trick - echolocation. By timing the echoes of their calls, one group effortlessly flies through the darkest of skies and the other swims through the murkiest of waters. It's amazing enough that two such different groups of mammals should have evolved the same trick but that similarity isn't just skin deep. The echolocation abilities of bats and whales, though different in their details, rely on the same changes to the same gene - Prestin. These changes have produced such…
A polar bear (Ursus maritimus), playing with a plastic ring at the Bronx Zoo.
A ring-tailed lemur (Lemur catta), photographed at the Bronx Zoo. Who doesn't love lemurs? The strepsirrhine primates, or wet-nosed cousins of ours, are favorite documentary subjects and extremely popular zoo attractions. And, in one of those bits of zoological trivia that everyone knows, lemurs only live on the island of Madagascar off Africa's southeastern coast. The question is how they got there. Documenting the paths of animals during geological history is not an easy task. In the days before scientists understood plate tectonics, land bridges, now sunk beneath the ocean, were often…
A stuffed Virginia opossum (Didelphis virginiana), photographed at the North Carolina Museum of Natural Sciences.
The restored lower jaw of Arcanotherium (formerly Numidotherium savagei). (From Delmer, 2009) Unlike the folks at this past weekend's ScienceOnline 2010 meeting, fossils don't come with nametags. The identification of preserved bits of ancient life relies upon careful comparison with what is already known, a task made all the more difficult for vertebrate paleontologists by the fragmentary nature of many of their subjects. Scraps of bone given one name could turn out to be parts of another partial skeleton given another name, or other bits of bone attributed one name could turn out to be…