The eyes have it: Cats put sight over smell in finding food

Date:

February 26, 2015

Source:

University of Lincoln

Cats may prefer to use their eyes rather than follow their nose when it comes to finding the location of food, according to new research by leading animal behaviourists.

Felines have a tremendous sense of smell and vision, but the new study by researchers at the University of Lincoln, UK, has for the first time investigated which sense they prefer to use under test conditions -- and suggested sight may be more important than smell.

A group of six cats were placed in a maze which had 'decision' points -- and the cats had to choose which avenue they took based on their preference for using images or smell. They were simultaneously presented with two squares of paper, each containing a different visual and odour cue. One combination of stimuli indicated they would receive a food reward, whereas the other led to no reward.

Once the cats had learned the rules of the game and received food rewards for correctly choosing either the visual stimulus or the olfactory stimulus, the researchers separated the cues (visual versus olfactory) to investigate whether the cats were using their eyes or nose to solve the task.

Continued ...

Why do snakes flick their tongues?

31st July 2014

41 minutes ago by Andrew Durso

Many people think a snake's forked tongue is creepy. Every so often, the snake waves it around rapidly, then retracts it. Theories explaining the forked tongues of snakes have been around for thousands of years. Aristotle reasoned that it provided snakes with "a twofold pleasure from savours, their gustatory sensation being as it were doubled".

Italian astronomer Giovanni Hodierna thought snake tongues were for cleaning dirt out of their noses. Some 17th century writers claimed to have watched snakes catch flies or other animals between the forks of their tongues, using them like forceps. It is a common myth even today that snakes can sting you with their tongues. But none of those hypotheses is likely.

Most animals with tongues use them for tasting, to clean themselves or others, or to capture or manipulate their prey. A few, including humans, also use them to make sounds. Snakes do not use their tongues for any of these things. Over the past 20 years, Kurt Schwenk, an evolutionary biologist at the University of Connecticut, has been working on understanding the function of snake tongues, and "smelling" is the closest description of what snakes do with their tongues.

Read more at: http://phys.org/news/2014-07-snakes-flick-tongues.html#jCp

Pirate Perch Probably Use Chemical Camouflage to Fool Prey

Mar. 28, 2013 — It’s a nocturnal aquatic predator that will eat anything that fits in its large mouth.

Dark and sleek, it hides beneath the water waiting for prey. A Texas Tech University researcher says the target will never know what hit them because they probably can’t smell the voracious pirate perch.

After careful investigations, William Resetarits Jr., a professor of biology at Texas Tech, and Christopher A. Binckley, an assistant professor in the Department of Biology at Arcadia University, found that animals normally attuned to predators from their smell didn’t seem to detect the pirate perch. It could be the first animal discovered that is capable of generalized chemical camouflage that works against a wide variety of prey.

The team published their findings in the peer-reviewed journal The American Naturalist.

Thankfully, at five-and-a-half inches long, only insects, invertebrates, amphibians and other small fish need worry about the danger hiding near the bottom among the roots and plantlife, Resetarits said.

“We use the term ‘camouflage,’ because it is readily understandable,” he said. “What we really are dealing with is some form of ‘chemical deception.’ The actual mechanism may be camouflage that makes an organism difficult to detect, mimicry that makes an organism difficult to correctly identify, or cloaking where the organism simply does not produce a signal detectable to the receiver.”

Read on: http://www.sciencedaily.com/releases/2013/03/130329085941.htm

Storm petrel seabirds can smell their relatives

Seabirds are able to pick out their relatives from smell alone, according to scientists.

In a "recognition test", European storm petrels chose to avoid the scent of a relative in favour of approaching the smell of an unrelated bird.

The researchers think this behaviour prevents the birds from "accidentally inbreeding".

The study is the first evidence that birds are able to sniff out a suitable mate.

It is published in the journal Animal Behaviour.

Lead researcher Francesco Bonadonna, from the Centre of Functional and Evolutionary Ecology in Montpellier, France, told BBC Nature that the birds used smell to recognise and communicate their "genetic compatibility".

Sniffing out a genetically suitable mate is a well-known phenomenon in mammals. But until recently, scientists thought that birds relied on vision and sound when choosing a partner.

According to Dr Bonadonna, the fact that they use odours explains how these birds manage to return to their family colony to breed and avoid mating with a relative.

Continued:  http://www.bbc.co.uk/nature/18884757