mammals
laelaps | January 28, 2008
The skeleton of an Irish Elk (Megaloceros giganteus) at the AMNH.
Discussions of mass extinctions nearly always give rise to heated debates as to the mechanism(s) behind the disappearance of so many taxa in a short amount of time, and one of the most active debates still surrounds the extinction of Pleistocene megafauna. All over the world the extinction of large animals appears to be correlated with the movements of our own species, Homo sapiens, into new territories. Disease and climate change have their own parts to play, the "Overkill Hypothesis" is perhaps the most popular explanation…
laelaps | January 28, 2008
It may not be perfectly framed, but I still love the intensity of the stare of the Amur leopard (Panthera pardus orientalis) in this photo. In the wild this subspecies of leopard exists essentially as a remnant population, only about 40 being left in the wild. Conservation efforts to shore up those numbers are a bit stunted due to political concerns, the Amur leopard being less popular/charismatic than the Amur tiger, etc., and it seems very probable that this subspecies could be lost.
laelaps | January 27, 2008
One of the three Amur tiger (Panthera tigris altaica) cubs born last year at the Philadelphia Zoo (photo taken in September).
grrlscientist | January 25, 2008tags: jaguar, Panthera onca, photography, subway art, AMNH, NYC, NYCLife
Jaguar, Panthera onca,
as portrayed in tiles on the walls of the NYC uptown subway stop (A-B-C)
at 81st and Central Park West. (ISO, no zoom, no flash).
Image: GrrlScientist 2008 [wallpaper size].
Read more about the AMNH tile artworks and see the AMNH tile artworks photographic archives -- with all the animals identified.
laelaps | January 23, 2008
Josephoartigasia monesi may now be known as the largest rodent to have ever lived, but it still has a number of super-sized extant relatives. The fourth largest of living rodents is the mara (Dolichotis sp.), of which there are two species (the one pictured above is the Patagonian mara, Dolichotis patagonum). Although maras don't look quite like their relatives, perhaps seeming closer to rabbits than guinea pigs, they are true members of the Caviidae, and they are easily kept at zoos. Wild populations of maras are somewhat threatened by habitat loss and competition with introduced rodents,…
laelaps | January 19, 2008
These bottlenose dolphins (Tursiops truncatus) were from a group of about twelve that I saw last summer off Cape May, NJ. Recent molecular studies suggest that they may be another species, however; the Indo-Pacific bottlenose dolphin (Tursiops aduncus).
grrlscientist | January 17, 2008tags: researchblogging.org, Josephoartigasia monesi, Giant South American rodent, fossils, megamammals, Dinomyidae
The head of the newly-found Josephoartigasia monesi (A), in comparison to a South American rodent known as a pakarana, Dinomys branickii (B).
Image: G. Lecuona [larger size].
As a resident of NYC, you often hear stories of enormous rats that are aggressive enough to fight an alleycat -- and win. Even though I watch the rats run around in the subways and am impressed by their audacity, I've never seen any rats that had reached a particularly impressive size, although I have…
laelaps | January 16, 2008
Thanks to conservation efforts, gray wolves in various parts of the United States have made a comeback, enough to potentially be removed from the endangered species list, but not everyone is happy that the wolves are doing so well. Indeed, if plans move forward to remove the protected status of wolves in the Northern Rockies region of the U.S., at least three states (Idaho, Wyoming, and Montana) are planning on setting up public hunts with rock-bottom prices for permits, possibly reducing the population back down to 300. Some members of Congress have protested the potential removal of the…
laelaps | January 16, 2008
A capybara (Hydrochoerus hydrochaeris) at the Cape May Zoo. Josephoartigasia dwarfs this animal, the largest of the living rodents.
One of the most interesting evolutionary patterns is an increase in the disparity of sizes in a group, small representatives persisting and changing even as some lineages get larger (I'll address this issue a bit more in a separate piece of Cope's Rule, if such a thing even truly exists). A new Pleistocene fossil rodent from Uruguay called Josephoartigasia monesi further elucidates this trend, being the largest fossil rodent yet discovered with an estimated…
laelaps | January 16, 2008
The endangered Grevy's zebra (Equus grevyi) is the largest species of zebra, and while it hasn't undergone the same level of taxonomic reshuffling that its relative the plains zebra Equus quagga) has, it still has been difficult to place at times. According to the IUCN page for Grevy's zebra, this horse is largely suffering from competition with people, overgrazing by livestock being one of the primary reasons this species is in decline. As far as is currently known Grevy'z zebra do not appear to be increasing in number and populations will likely continue to shrink. The individual pictured…
laelaps | January 7, 2008 It may not be a new paper, but this afternoon I came across an article by Mark Hafner published in the Journal of Mammalogy called "Field Research in Mammalogy: An Enterprise in Peril" that definitely struck a chord with me. When I decided to enter into the ecology & evolution major at Rutgers, I assumed that I would eventually be introduced to some field work and be able to focus on vertebrate zoology, but much to my dismay no such program seemed to exist. Much of the learning involved taxonomy in the lab, which (don't get me wrong) is important, but field studies seemed to be entirely…
laelaps | January 5, 2008
Giant otter (Pteronura brasiliensis) are, as the name would suggest, the largest living otters and the largest representatives of the Mustelidae. As anyone who has seen these animals in captivity or the wild can attest, they are also among the most gregarious of all mustelids and emit ear-piercing squeaks, squeals, and barks as they move around together. Groups are typically centered around a dominant breeding pair, residents defending territories against transients, and average group size is between 3 to 8 individuals.
laelaps | January 4, 2008
Giant pandas might get most of the media attention, but red pandas (Ailurus fulgens) are in just as much trouble from a conservation standpoint. Habitat fragmentation is the greatest threat (as it is with many species), outside pressures from humans worsening the situation for these animals as they have a naturally occurring slow birth rate and high death rate. As with other animals from Asia, products made from various parts of the red panda are important to various ceremonies and the animals are still hunted and poached, especially for their hides. The individual above was photographed at…
laelaps | January 3, 2008
The brown bear (Ursus arctos) is the second largest living bear (the largest being the polar bear, Ursus maritimus), but depending on where you are in the world it can go by many names and vary in appearance. At present there seems to be a glut of possible brown bear subspecies that scream for proper revision, from the familiar grizzly bear (Ursus arctos horribilis) to the strange Tibetan blue bear (Ursus arctos pruinosus). Further adding to some of the confusion are rare hybrids produced from the mating of a polar bear and a brown bear, a wild example of this sort of pairing being…
laelaps | January 2, 2008 Throughout most of the world humans have exterminated carnivores in order to keep their places of habitation safe, and while large carnivores still exist in patches we have a sort of "You keep to your side, I'll keep to my side," sort of attitude towards them. The problem, however, is that we keep expanding our towns and villages out into areas where large carnivores live, some areas experiencing an increased level of conflict. Leopards eat stray dogs in the slums of Mumbai, wolves kill dogs left outside in Alaska, black bears raid trash cans in New Jersey suburbs, and even polar bears are…
jlynch | January 1, 2008
Daubenton’s Bat, Myotis daubentonii Kuhl 1817, hunting over water.
Named in honor of the French naturalist Louis-Jean-Marie Daubenton who died today in 1800. [source]
laelaps | January 1, 2008
If you visit zoos often enough, you'll probably eventually see at least one pair of animals mating with each other. While I didn't actually see the two gerenuk (Litocranius walleri) in flagrante delicto, the male chased the female around a bit with that intention. Much like a cat in heat, the female gerenuk (the one without horns) crouched down and lifted up her tail, and this put the male (the one with horns) in hot pursuit. If there was a successful mating and fertilization, then about seven months later there would have been a baby gerenuk born at the zoo. As I've said before when…
laelaps | December 28, 2007
Following up on yesterday's post on marsupials, here's a photo of two Gray Kangaroo (Macropus sp.) at the Turtleback Zoo in New Jersey. The largest macropod to have ever lived, though, was the extinct Procoptodon goliath, a short-faced giant that would have stood about 10 feet tall when upright.