mammals
laelaps | September 10, 2009
Why did this male pronghorn (Antilocapra americana) cross the road?
To chase away some other males on the other side! (Though he had no beef with the bison.) Photographed at Antelope Island.
laelaps | September 9, 2009
A Smilodon fends off vultures at what would later be called the Rancho La Brea tar pits, situated in Los Angeles, California. Painting by Charles R. Knight.
The feeding habits of saber-toothed cats have long perplexed scientists. How in the world did these cats kill prey with their almost comically-oversized teeth? Did Smilodon and its kin use their teeth like daggers to stab prey to death, or did they simply rip out a huge chunk of flesh from the side of a victim, leaving their prey to hemorrhage to death?
While the stabbing hypothesis has generally been abandoned it is still a mystery…
edyong | September 9, 2009When food is precious, animals can resort to strange behaviours in order to satisfy their hunger. Take the great tit. Its usual diet of insects and creepy-crawlies is harder to come by in winter. But in one Hungarian cave, great tits, ever the opportunists, have learned to exploit a rich and unusual source of food. They kill sleeping bats.
Great tits are only about 5 inches long, but their prey - the pipistrelle bat - is smaller still, just an inch or two in size. The bats spend the winter months hibernating in rock crevices. They're well hidden, but when they wake up, they start making…
laelaps | September 8, 2009
A young bison (Bison bison) walking along the road during a bison jam in Yellowstone.
edyong | September 7, 2009The natural world is rife with leftovers. Over the course of evolution, body parts that no longer benefit their owners eventually waste, away leaving behind shrivelled and useless anatomical remnants. The human tailbone is one such example. Others include the sightless eyes of cavefish that live in total darkness, the tiny spurs on boas and pythons that hint at the legs of their ancestors, and the withered wings of the Galapagos cormorant, an animal that dispensed with flight on an island bereft of land predators.
Animal genomes contain similar remains. Just like organs, genes also waste…
grrlscientist | September 7, 2009tags: nature, mammals, Antarctica, humpback whale, Megaptera novaeangliae, David Attenborough, streaming video
Faint disturbances in the heart of Antarctic waters gives way to breathtaking images of Humpback Whales, Megaptera novaeangliae, hunting Krill in this fantastic video clip from BBC's natural history television masterpiece, Planet Earth. Narrated by the incomparable David Attenborough.
laelaps | September 6, 2009
A male elk (Cervus canadensis) grazing among a group of fallen trees. Photographed near the West Thumb Geyser Basin in Yellowstone.
laelaps | September 5, 2009
A family of North American river otters (Lontra canadensis) playing together, photographed at a pond in Yellowstone's Lamar Valley.
edyong | September 4, 2009Domestic dogs are very different from their wolf ancestors in their bodies and their behaviour. They're more docile for a start. But man's best friend has also evolved a curious sensitivity to our communication signals - a mental ability that sets them apart from wolves and that parallels the behaviour of human infants. Dogs and infants are even prone to making the same mistakes of perception.
Like infants less than a year old, dogs fail at a seemingly easy exercise called the "object permanence task". It goes like this: if you hide an object somewhere(say a ball under a cup) and let the…
laelaps | September 4, 2009
A sign warning visitors about elk at Mammoth Hot Springs in Yellowstone (with a female elk in the background). The well-groomed lawns there provided a 24/7 buffet for the herbivores.
Some people ignored the signs.
laelaps | September 3, 2009
A black bear (Ursus americanus) walking along the trail near Leigh Lake in Grand Teton National Park. It was one of two black bears I saw along the trail that afternoon.
laelaps | September 2, 2009
A female mule deer (Odocoileus hemionus) photographed by the road in Grand Teton National Park.
laelaps | September 1, 2009
A lone female elk in the morning fog near Grizzly Lookout. I had heard one of the Hayden Valley wolf packs in this area just a few minutes before taking this photo.
While traveling through Yellowstone National Park I was struck by the way in which the park's wilderness is being reshaped and redefined every day. Yellowstone workers and administrators have engaged in a herculean effort to restore the wildness of the nation's first national park, from the celebrated reestablishment of the bison herds to the cessation of bear feeding at park garbage dumps, but there still are tensions between…
laelaps | September 1, 2009
A group of bison (Bison bison) walking down the road in Yellowstone National Park, not far from Uncle Tom's Trail. The roads are frequently used by the bison and have been important to the population's recovery within the park.
laelaps | August 31, 2009
The larger of the two dogs in the campground in Wyoming's Wind River Range mountains.
After more than an hour of navigating the pothole-pocked dirt road leading up to the park Tracey and I finally made it to our campsite in the Big Sandy Opening in Wyoming's Wind River Range. It was cold despite the sunshine, especially considering that we had spent the previous day (the 17th) splitting Eocene-age shale in a heat-baked rock quarry. It wasn't long after we began to unpack that the dog appeared.
We thought she belonged to someone else. She was an adult Pyrenean Mountain Dog, and was happily…
laelaps | August 31, 2009
A male pronghorn (Antilocapra americana), photographed yesterday morning at Antelope Island State Park, Utah.
laelaps | August 31, 2009
A black bear, photographed at Grand Teton National Park.
I'm back! I have a lot of cleaning up to do (both around the apartment and on this blog, especially the latter because of all the spam that has accumulated during my absence), but I thought I would post something to let you all know that I made it home safely. It was a wonderful trip. I have lots of photos and stories to share, so watch this blog and Dinosaur Tracking during the next few weeks for all the details.
laelaps | August 17, 2009
Osborn's view of the progressive evolution of the brontotheres. Notice the references to the "geneplasm" at left, which Osborn interpreted as spontaneously giving rise to new adaptations. From Osborn (1935).
Every now and then I like taking a break from the latest technical papers and conference volumes to read some vintage scientific work. Oftentimes this is an enjoyable experience, I love the history of science, but the evolutionary work of H.F. Osborn is frustratingly opaque. While Osborn certainly was one of the most prominent figures in early 20th century paleontology he cultivated…
laelaps | August 16, 2009
An eastern cottontail rabbit (Sylvilagus floridanus), photographed in Cape May, NJ.