Animal cognition



Crows using two tools to get food

By Rebecca Morelle Science reporter, BBC News

A University of Auckland study has revealed that New Caledonian crows can use separate tools in quick succession to retrieve an out-of-reach snack. (Current Biology) New Caledonian crows are renowned for their tool-making ability. The birds (Corvus moneduloides), which are found on the South Pacific island of New Caledonia, use their bills to whittle twigs into hooks and cut and tear leaves into barbed probes that can extract bugs and grubs from crevices. To further test the crows' tool-using talents, scientists set seven wild birds a tricky task. The crows were presented with: A scrap of meat, which was tucked away, out of reach, in a box; A small twig, which was too short to reach the food; And another longer twig, which was long enough to reach the food, but was locked away well out of bill-grabbing range in another box. Alex Taylor, lead author of the paper, said: "The creative thing the crows did was to use the short stick to get the long tool out of the box so that they could then use the long stick to get the meat."

Mouse brain simulated on computer

US researchers have simulated half a virtual mouse brain on a supercomputer. The scientists ran a "cortical simulator" that was as big and as complex as half of a mouse brain on the BlueGene L supercomputer. 2007.04

For First Time, Chimps Seen Making Weapons for Hunting

Washington Post Friday, February 23, 2007; Page A01

Chimpanzees living in the West African savannah have been observed fashioning deadly spears from sticks and using the tools to hunt small mammals -- the first routine production of deadly weapons ever observed in animals other than humans. The multistep spearmaking practice, documented by researchers in Senegal who spent years gaining the chimpanzees' trust, adds credence to the idea that human forebears fashioned similar tools millions of years ago. ... Using their hands and teeth, the chimpanzees were repeatedly seen tearing the side branches off long, straight sticks, peeling back the bark and sharpening one end. Then, grasping the weapons in a "power grip," they jabbed them into tree-branch hollows where bush babies -- small, monkeylike mammals -- sleep during the day. In one case, after repeated stabs, a chimpanzee removed the injured or dead animal and ate it, the researchers reported in yesterday's online issue of the journal Current Biology.

BBC - Ancient chimps 'used stone tools'

Chimpanzees in West Africa used stone tools to crack nuts 4,300 years ago. The discovery represents the oldest evidence of tool use by our closest evolutionary relative. The skill could have been inherited from a common ancestor of chimps and humans, the authors say, or learnt from humans by imitation. Alternatively, humans and chimps may have developed tool use independently, the Proceedings of the National Academy of Sciences journal reports. Chimpanzees were first observed using stone tools in the 19th century. Julio Mercader and colleagues found stone tools at the Noulo site in Ivory Coast, the only known prehistoric chimpanzee settlement. The excavated stones showed the hallmarks of use as tools for smashing nuts when compared with ancient human or modern chimpanzee stone tools.

Fish can infer transitive social rank by observation alone

Nature 445, 429-432 (25 January 2007) doi:10.1038/nature05511

Logan Grosenick, Clement and Fernald

Transitive inference (TI) involves using known relationships to deduce unknown ones (for example, using A > B and B > C to infer A > C), and is thus essential to logical reasoning. First described as a developmental milestone in children1, TI has since been reported in nonhuman primates2, 3, 4, rats5, 6 and birds7, 8, 9, 10. Still, how animals acquire and represent transitive relationships and why such abilities might have evolved remain open problems. Here we show that male fish (Astatotilapia burtoni) can successfully make inferences on a hierarchy implied by pairwise fights between rival males. These fish learned the implied hierarchy vicariously (as 'bystanders'), by watching fights between rivals arranged around them in separate tank units.

Language evolution: Semantic combinations in primate calls

Putty-nosed monkeys rely on two basic calling sounds to construct a message of utmost urgency.


Cultural transmission in Dolphins

Tue Jun 7, 4:24 PM ET

Dolphin mothers in Western Australia teach their daughters how to use a sponge to forage for food, yet another example of how animals learn to use tools.

The animals that used the sponges all seemed to be related, but the researchers could not find any genes associated with the behavior, they report in this week's issue of the Proceedings of the National Academy of Sciences.

Michael Kruetzen of the Anthropological Institute and Museum at the University of Zurich in Switzerland and colleagues watched the dolphins at work in Shark Bay in Western Australia.

For years researchers have seen the dolphins pick up sponges with their beaks and then use them as they poked along the sea beds, evidently to protect their delicate snouts from spiny fish.

Kruetzen's team analyzed DNA from 13 "spongers" and 172 dolphins that did not display this behavior. While the sponging animals all seemed related along the female line, there was no genetic link.

Word Learning in a Domestic Dog: Evidence for "Fast Mapping"

Science, Vol 304, Issue 5677, 1682-1683 , 11 June 2004 doi:10.1126/science.1097859

Juliane Kaminski, Josep Call, Julia Fischer*

During speech acquisition, children form quick and rough hypotheses about the meaning of a new word after only a single exposure—a process dubbed "fast mapping." Here we provide evidence that a border collie, Rico, is able to fast map. Rico knew the labels of over 200 different items. He inferred the names of novel items by exclusion learning and correctly retrieved those items right away as well as 4 weeks after the initial exposure. Fast mapping thus appears to be mediated by general learning and memory mechanisms also found in other animals and not by a language acquisition device that is special to humans.

Animal behaviour: Geomagnetic map used in sea-turtle navigation

Nature 428, 909 - 910 (29 April 2004); doi:10.1038/428909a

These migratory animals have their own equivalent of a global positioning system.

Migratory animals capable of navigating to a specific destination, and of compensating for an artificial displacement into unfamiliar territory, are thought to have a compass for maintaining their direction of travel and a map sense that enables them to know their location relative to their destination1. Compasses are based on environmental cues such as the stars, the Sun, skylight polarization and magnetism2, but little is known about the sensory mechanism responsible for the map sense3, 4. Here we show that the green sea-turtle (Chelonia mydas) has a map that is at least partly based on geomagnetic cues.