Further: European magpies
(Pica pica) are traditionally viewed as the
thieves of the bird world.
In lore the these clever corvids cannot resist things that sparkle and will routinely steal small, bright objects for their nests including jewelry. NOT says a new study from the University of Exeter; the species is actually frightened by new and unfamiliar objects. All the recorded observations show both wild and rescued birds have a fear of new things be they
sparkly or no. Scientists attribute the folklore to a cultural generalization of anecdotes rather than objective observation. The study was carried out on the campus of Exeter U. where magpies are accustomed to human activity. They tested shinny metal screws, foil rings, and small retangles of aluminum foil. Half of the objects were painted with matte paint and the other half left in shiny condition. Food was placed near piles of the shiny and painted objects. In only 2 of 64 tests did the wild magpie subject choose a bright object--foil rings--which it immediately discarded. Captive birds ignored the non-food objects altogether. The authors of the study say the experiment again demonstrates the intelligence of corvids who have large brains and a complex social system. They are not compulsively drawn to a shiny object but are able to decide to keep a safe distance when confronted with novel or unexpected conditions.
{25.08.14} More: A new study shows that ravens are benefiting from man's disruption of the natural landscape. The study sponsored by the Wildlife Conservation Society, USGS and Idaho State University, looked at the nesting habits of a variety of bird predators living in Idaho sagebrush prairie over a three year period. Compared to red-tailed, Swainson's and ferruginous hawks, common ravens are adapting well to artificial structures such as mobile phone towers, transmission towers, billboards and buildings. Of the four species, ravens overwhelmingly prefer man's constructions as nest sites. The three hawks stay away from artificial structures. Classified as an uncommon breeder in 1986, ravens now predominate with 46% of the nests in the study site. These corvids have a long history of symbiotic relationship with man. Anecdotes of ravens leading human hunters to prey abound; consequently the bird has achieved totemic status in North American tribal culture. Ravens have also adapted well to modern urban environments, aided by their opportunistic foraging and high intelligence. Hawks tend to be strongly territorial, intolerant of humans, and prefer live prey that occupy similar habitats.
US Person has often seen ravens mobbing red tail hawks and driving them away with repeated dives against the larger bird of prey. Another piece of bad news for hawks and the sage grouse on which they prey is that ravens young birds and eggs without regard to species.
{18.08.14} US Person is always intrigued by ravens that inhabit his suburban neighborhood. Observing them one can see their intelligence as they nonchalantly dodge traffic while picking up scraps of road kill, or notice their strong bonds as they forage on the ground in family groups of two, three or four. Their vociferous squabbles with
neighbors are equally apparent, yet family members often communicate with each other in a small voice. Humans are greeted with raised head feathers, an alarm display. The family of corvids (Corvidae) includes ravens, crows, and jays and magpies. Biologists are beginning to understand just how intelligent this bird family is. European magpies have exhibited self-awarness in experiments, and crows (especially a New Caledonia species) are observed using tools. Their brain-to-body mass is equal to great apes and whales, only slightly less than humans.
But can corvids think about thinking? Humans do this all the time as they constantly plan their next move and anticipate the results. This higher level of cognition is called by scientists metacognition. Finding it in animals is tricky because such a complex process can often be explained by simpler behaviors. Studies of apes and birds have not been able to isolate metacognition until a recent study involving scrub jays, species of corvid. Western scrub jays
(Aphelocoma californica) are known to have complex memories because they store surplus food in scattered, hidden caches that they can accurately recover after long periods of time. They also steal from other birds' caches based on an accurate memory of observation. To reduce food pilferage, they sometimes store bright, but inedible objects that might attract a thief, and they look around for bird "
spies" before making a cache. Scrub jays seem to have a mischevious streak along with obvious intelligence.
So a scientist at Cambridge University naturally picked scrub jays as his experimental subject when testing for metacognition in birds. The question is: are scrub jays aware they are thinking? Arii Watanabe devised a clever plan to answer the inquiry. Five jays were allowed to watch researchers hide a wax worm. One research hid a worm in one of four open cups; another researcher also had four cups, three of which were covered. The second worm was put in the one open cup out of four. Both researchers hid their worms at the same time, thus allowing the jays to choose which human to watch. If scrub jays used metacognition, they could understand that watching the second researcher with only one open cup would allow them to easily find his worm; consequently, they could spend more time watching the first researcher hide her worm in one of four identical cups. Remembering in which cup that worm was placed could be useful in the future, just as memorized spatial information is useful to a wild jay retrieving a cache made weeks ago. Results came in and the jays passed! They spent more time watching the first researcher. Watanabe's results are published in the peer journal
Animal Cognition. His experiment does not prove scrub jays have consciousness in the human sense, but as Watanabe describes it, "some birds study for a test like humans do." But then not all humans do that much.
