Posts Tagged ‘Predators’

New Zealand Bird Outwits Alien Predators

June 8, 2008

New research led by Dr Melanie Massaro and Dr Jim Briskie at the University of Canterbury, which found that the New Zealand bellbird is capable of changing its nesting behaviour to protect itself from predators, could be good news for island birds around the world at risk of extinction.

The introduction of predatory mammals such as rats, cats and stoats to oceanic islands has led to the extinction of many endemic island birds, and exotic predators continue to threaten the survival of 25 percent of all endangered bird species worldwide

[…] But their study on the bellbird, an endemic New Zealand bird, has identified the ability of a previously naïve island bird to change its nesting behaviour in response to the introduction of a large suite of exotic mammalian predators by humans.

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Success By Learning: Smallest Predator Recognizes Prey By Its Shape

May 22, 2008

The Etruscan shrew (Suncus etruscus) is one of the world’s smallest mammals. It is about four centimetres long and weighs merely two grams. Being a nocturnal animal, it hunts predominantly with its sense of touch. Professor Michael Brecht (Bernstein Center for Computional Neuroscience, Berlin) now reported on the particularities of its hunting behaviour at the international conference “Development and function of somatosensation and pain” at the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch, Germany. “As quick as a flash, the Etruscan shrew scans its prey and adapts, when necessary, its hunting strategy,” explained Brecht in his talk. “Thus, no prey escapes.”

The smaller an animal is, the greater is its loss of warmth over its surface. To avoid starvation, the Etruscan shrew has to constantly compensate for this life-threatening energy loss. Thus, it consumes twice its weight every day and feeds on crickets, cockroaches, and spiders. Since the prey are nearly as big as their predator, the shrew has to attack fast and well directed.

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Birds Can Detect Predators Using Smell

May 6, 2008

Many animal species detect and avoid predators by smell, but this ability has largely been ignored in the study of birds, since it was traditionally thought that they did not make use of this sense. However, it has now been discovered that birds are not only capable of discerning their enemies through chemical signals, but that they also alter their behaviour depending on the perceived level of risk of predation.

The use of smell to detect chemical signals can be useful for birds in various situations, such as feeding and orientation. However, they can greatly increase their chances of survival if they can tell whether or not the smell they have detected is associated with a predator. Luisa Amo de Paz, the study’s lead author, explained that: “Birds can detect the presence of a predator” thanks to their sense of smell. Working as a biologist at the Spanish National Research Council’s (CSIC) Natural History Museum while the study was carried out, Ms. Amo de Paz is currently working for the Netherlands Institute of Ecology (NIOO-KNAW).

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Birds Announce Their Sentry Duty To Help Comrades Get A Good Meal

April 22, 2008

Soldiers on sentry duty in hostile territory keep in regular radio contact with their colleagues to assure them that all is well and that they are safe to carry on their manoeuvres. New research reveals that this is also a feature of the bird world and is very likely to be a rare example of truly cooperative behaviour.

Researchers from the University of Bristol, led by BBSRC David Phillips Fellow Dr Andy Radford, have demonstrated that by giving the distinctive ‘watchman’s song’, individuals scanning for danger as sentinels ensure that their group-mates can focus on foraging, and so capture more food. Dr Radford said: “These exciting results point to a great example of true cooperation. The unselfish behaviour of the sentry is probably rewarded down the line by the improved survival of group mates, which leads to a larger group size. This increases the sentinel’s chances of survival when the group is under attack from predators or having to repel rivals from their territory. It’s a win-win scenario!”

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Novel Living System Recreates Predator-prey Interaction

April 14, 2008

The hunter-versus-hunted phenomenon exemplified by a pack of lionesses chasing down a lonely gazelle has been recreated in a Petri dish with lowly bacteria.

Working with colleagues at Caltech, Stanford and the Howard Hughes Medical Institute, a Duke University bioengineer has developed a living system using genetically altered bacteria that he believes can provide new insights into how the population levels of prey influence the levels of predators, and vice-versa.

The Duke experiment is an example of a synthetic gene circuit, where researchers load new “programming” into bacteria to make them perform new functions. Such re-programmed bacteria could see a wide variety of applications in medicine, environmental cleanup and biocomputing. In this particular Duke study, researchers rewrote the software of the common bacteria Escherichia coli (E. coli.) to form a mutually dependent living circuit of predator and prey.

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