Ecology & Zoology
BOSTON, MA—“The trees are certainly shorter out here,” said Luke.
The East Coaster in me bristled instantly. “Well, sure, nothing’s going to measure up to a Redwood,” I said, “but these guys along the road are hardly the best that Massachusetts has to offer.”
As Luke mused out loud over the tall trees that could be found in his home state of Oregon, I thought about what the forests of the Northeastern United States would have looked like centuries before the highway we now cruised was constructed.
The fossilized fangs of saber-toothed cats, a leopard-sized Promegantereon ogygia and a much larger, lion-sized Machairodus aphanistus, hold clues to how large, extinct mammals once shared space and food with other large predators 9 million years ago.
Paleontologists have analyzed the tooth enamel of two species of saber-toothed cats and a bear dog unearthed in geological pits near Madrid. Bear dogs, also extinct, had dog-like teeth and a bear-like body and gait.
Squid typically die after spawning. Their orphaned eggs are left alone in the cold brine to develop and hatch, never knowing a mother's tender caress.
But as in all of biology
, there are exceptions.
It's strangely appropriate that the second of these exceptions has entered, stage left, just as I am preparing to exit, stage right, in order to engage in the intensive parental care typical of humans. I'll be spawning within the next few weeks, and taking a hiatus from the blogosphere to focus on my in-home developmental biology experiment.
Researchers estimate that artificial lighting is increasing at a rate of 6% each year around the world. This could dramatically reduce the amount of "naturally unlit habitat" available to wildlife, and have significant impacts on organisms that have evolved to deal with specific characteristics and regimes of light. By altering how much light is present in a habitat, where it occurs, how bright it is, what wavelengths it contains, and when it illuminates the environment, we might inadvertently impact a variety of wildlife traits, including behaviors (such as foraging, navigation, and communication), physiology (including cyclical release of hormones and other important chemicals), and interactions with other species.
1.8 million years ago, giant German hippopotamuses wallowed on the banks of the Elbe.
Hippos were all over Europe then, along with other megafauna like woolly mammoths and giant cave bears. What went wrong? Palaeontologists blame global cooling during the Pleistocene Era, which may have forced Europe’s hippos to shrink to pygmy sizes before finally driving them to warmer climes.
In the African savannah can reach 149° Fahrenheit in the middle of the day, which leads to burning sand and an obvious problem for anything that lives there, including small insects that spend their lives on the surface of the sand. Some insects seek protection in the shade or climb up blades of grass to escape the worst of the heat.
But South African dung beetles have come up with a unique strategy to escape the heat of the sun; they climb on top of their rolled-up meal, which happens to be a ball of dung. These dung balls are a kind of air conditioning unit because the ball is made from the moist dung of a large(ish) mammal. When the moisture in the dung ball evaporates in the heat, the ball is cooled down.
Although individuals of a particular species frequently differ in a variety of characteristics, the implications of those differences are often not well understood. One exception to this general rule is the known positive impacts of size and condition, but what about the effects of certain preferences and choices--the tendency, for example, to utilize one type of habitat rather than another? A recent study on woodland caribou (Rangifer tarandus caribou) suggests that individual variations can literally be a matter of life and death--in this case not for the animals themselves, but for their offspring.
Dogs are susceptible to contagious yawning just like people, says an article in Animal Cognition, but only after they get older. Dogs, like humans, show a gradual development of susceptibility to contagious yawning and the new paper says dogs catch yawns from humans. But Only dogs above seven months of age catch these human yawns - younger dogs are immune to the contagion.
Contagious yawning has been researched in humans, adult chimpanzees, baboons and dogs, some speculate it can be used as a measure of empathy. Empathy, mimicking the emotional responses of others, is difficult to measure directly, but contagious yawning allows assessment of a behavioral empathetic response, the Swedish researchers say.
The best reasons to allow hunting in animal-heavy states are that they get hit by cars a lot and they starve. When it comes to cars, some areas are going to be a lot more dangerous than others and it is not a question of how many animals are there but simply where the road is. They have done things their way for 6,000 years and don't want to change, regardless of what automobiles might like.
But the animals will go over. Case in point: The Wildlife Conservation Society (WCS) has announced the successful use of newly constructed overpasses that provide safe passage for thousands of migrating pronghorn over U.S. Highway 191 in Trapper’s Point, Wyoming, and surrounding areas.
Body hair in mammals is typically thought to have evolved to keep us warm in colder prehistoric periods but in elephants it may do the opposite. A new study contends epidermal hair may have evolved to help the animals keep cool in the hot regions they live in.
Low surface densities of hair can help dissipate heat but the biological and evolutionary significance of sparse skin hair is not well known. The authors of the new paper studied the effects of skin hair densities in Asian and African elephants on thermoregulation in these animals, and concluded that elephant skin hair significantly enhances their capacity to keep cool under different scenarios like higher daytime temperatures or less windy days.