Ecology & Zoology

For lemurs, genetic diversity and scent complexity go hand in hand during the breeding season, say researchers from Duke University and the Centre d'écologie fonctionnelle et évolutive (CNRS / Universités Montpellier 1, 2 and 3 / ENSA Montpellier / CIRAD / École pratique des hautes études de Paris). Male lemurs are able to signal their genetic quality through an olfactory cue. The perfume attracts females and provides the basis for their choice of reproductive partner. Olfaction, little studied in primates until now (1), is a significant means of communication in certain monkeys, and…

Biologists at Harvard University have determined that some African frogs puncture their own skin with sharp bones in their toes when threatened, using the bones as claws capable of wounding predators. It's not quite the X-Men's Wolverine (they can't cut through Magneto) but it's a nifty defensive mechanism. "Most vertebrates do a much better job of keeping their skeletons inside," said David C. Blackburn, a doctoral student in Harvard's Department of Organismic and Evolutionary Biology. "It's surprising enough to find a frog with claws. The fact that those claws work by cutting through the…

Researchers have shown that the pre-hatching calls of baby Nile crocodiles actually mean something to their mothers - and even to their siblings. To us, they sound like "umph! umph! umph!" but to the others in the nest it's a signal that it's time to hatch, according to the report in Current Biology. When the mother hears those cries, she also knows it's time to start digging up the nest. The new findings, made from a series of "playback" experiments, confirm what had only been suspected on the basis of prior anecdotal observation, according to the researchers Amélie Vergne and Nicolas…

Like several other insect orders, the Lepidoptera is staggeringly diverse -- there are about 180,000 described species in the order and an untold number that remain unknown to biologists. (For comparison, there are about 5,000 mammal species). Most people know the Lepidoptera ("leps" to entomologists) as moths and butterflies. The incompleteness of their taxonomic descriptions reflects their sheer diversity rather than academic neglect -- leps have been collected and studied for centuries. As it turns out, the distinction between moths and butterflies probably is not phylogenetically…

Researchers have found that female red squirrels showed high levels of multimale mating and would even mate with males that had similar genetic relatedness, basically mating with their relatives. Researchers from the University of Alberta, in Edmonton, Alberta, Canada and the University of Sheffield in Sheffield, England, United Kingdom studied a population of red squirrels over a period of three years near Kluane National Park in southwest Yukon. While males mating with multiple females is quite common in the animal kingdom, females that multi-mate is much harder to explain. Through their…

Nitrogen is essential to all life on Earth, and determines how much carbon dioxide ecosystems can absorb from the atmosphere, says UC Davis assistant professor Benjamin Houlton. There are puzzling aspects of the nitrogen cycle in temperate and tropical forests. Defying laws of supply and demand, trees capable of extracting nitrogen directly from the atmosphere, nitrogen fixation, often thrive where it is readily available in the soil, but not where it is in short supply. Houlton tackled the problem with colleagues including top international ecologist Peter Vitousek, the Clifford G. Morrison…

The Nazca booby, a Galápagos Island seabird, emerges from its shell ready to kill its brother or sister. Wake Forest University biologists and their colleagues have linked the murderous behavior to high levels of testosterone and other male hormones found in the hatchlings. The research is part of a long-term study by Anderson that has included monitoring more than 16,000 Nazca booby nests at Punta Cevallos, Isla Espanola, in the Galápagos Islands since 1984. The elevated levels of male hormones, called androgens, increase aggression in both male and female chicks and prepare the birds to…

The temperature inside a healthy, photosynthesizing tree leaf is affected less by outside environmental temperature than originally believed, according to new research from biologists at the University of Pennsylvania. Surveying 39 tree species ranging in location from subtropical to boreal climates, researchers found a nearly constant temperature in tree leaves. These findings provide new understanding of how tree branches and leaves maintain a homeostatic temperature considered ideal for photosynthesis and suggests that plant physiology and ecology are important factors to consider as…

Scientists, reporting in the current issue of the online journal Marine Drugs, state that an increase of epileptic seizures and behavioral abnormalities in California sea lions can result from low-dose exposure to domoic acid as a fetus. The findings follow an analysis earlier this year led by Frances Gulland of the California Marine Mammal Center that showed this brain disturbance to be a newly recognized chronic disease. John Ramsdell of NOAA's Center for Environmental Health and Biomolecular Research in Charleston, SC, in partnership with Tanja Zabka, a veterinary pathologist at the…

The contentious debate about why insects evolved to put the interests of the colony over the individual has been reignited by new research from the University of Leeds, showing that they do so to increase the chances that their genes will be passed on. A team led by Dr Bill Hughes of the University’s Faculty of Biological Sciences studied 'kin selection' – the theory that an animal may pass on its genes by helping relatives to reproduce, because they share common genes, rather than by reproducing itself. The concept of ‘kin selection’ was developed in 1964 by the evolutionary biologist Bill…