Pref

Certain fish have a special mating preference

A biologist at Washington University in St. Louis has shown that for some fish species, females prefer males with larger sexual organs, and actually choose them for mating. That does not exclude males with an average-sized sex organ, called a gonopodium. These fish out-compete the larger-endowed males in a predator-laden environment because they have a faster burst speed than the males with large...

Older female fish prefer imperfect male mates, study finds

There's hope for the less-than-perfect male ?if you're a swordtail fish, that is. As the size and age of female swordtail fish increase, so does the preference for males with asymmetrical markings, according to a new Ohio University study. Molly Morris, associate professor of biological sciences, and colleagues found that older female swordtails spent more time with asymmetrically striped...

Have a taste for fat? Yes! A sensor in the mouth promotes preference for fatty foods

The sense of taste informs the organism about the quality of ingested food. It comprises five sub-modalities that perceive sweet, salt, sour, bitter, and umami stimuli. The possibility for an additional taste modality directed to lipid has often been suggested because many animals exhibit a spontaneous attraction for fats, but the existence of an actual sensor remained a matter of debate. <...

Both alcoholism and chronic smoking can damage the brain's prefrontal cortex

University of Utah researchers will receive up to $10.3 million to help develop a new prosthetic arm that would work, feel and look like a real arm. The Utah work is a key part of a U.S. Department of Defense contract worth up to $55 million to develop the new device for soldiers and potentially others whose arms were amputated. "Imagine an artificial arm that moves naturally in response t...

Man's best friend: Study shows lonely seniors prefer playtime with pooch over human interaction

A new Saint Louis University study shows there is some truth in the old cliché that describes a dog as "man's best friend." Nursing...

Predators prefer to hunt small-brained prey

They avoid more intelligent prey such as monkeys which have exceptionally large brains and are more capable of escaping attacks. The study, carried out by Dr Susanne Shultz, from the School of Biological Sciences, focused on predators from Africa and South America such as the jaguar, chimpanzee, leopard and puma. Dr Shultz found that prey with a small brain such as small antelope, mongoos...

Zebra finch males prefer females with exaggerated maternal traits

Researchers have demonstrated that learning about the appearance of their parents may give birds a preference for mates with exaggerated parental traits, rather than traits that more exactly match those of their parents. Such learned mate preferences may help drive the evolution of exaggerated traits and strong morphological differences between sexes ?phenomena seen frequently in birds and other...

Male chimpanzees prefer mating with old females

Researchers studying chimpanzee mating preferences have found that although male chimpanzees prefer some females over others, they prefer older, not younger, females as mates. The findings uncover a stark contrast between chimpanzee behavior and that of humans, their primate cousins. The basis for this difference may lie in the fact that whereas chimpanzees participate in a relatively promiscuous...

Human preference for other species could determine whether they survive

As humans exert ever-greater influence on the Earth, their preferences will play a substantial role in determining which other species survive. New research shows that, in some cases, those preferences could be governed by factors as subtle as small color highlights a creature displays. In the case of penguins, mostly black-and-white flightless birds that live predominantly in the Southern...