Received wisdom assumes that most non-human animals are almost entirely instinctual in their behaviors (except, of course, when humans deliberately train them either through stimulus-response mechanisms). This assumption underlies the fantasy that should human culture result in the extinction of most mammal and avian species, all humans need do to restore them is find a way to use extant genetic materials to bring these species back to life-- presumably just as they were. (I.e., that DNA=the magic blueprint for replication.)
Lately, though, I've been noticing reports (particularly in Science
) suggesting that education plays a role in birds' and mammals' behaviors. Crows, of course, have come in for a lot of attention over the last decade (though I suspect that even before scientists began to study crows' intelligence most of us already knew from personal observation that crows share information about particular humans with other crows, sometimes, disconcertingly, over a period of years). In the August 30 issue of Science
, though, researchers are now reporting that whooping cranes bred in captivity have to be taught
migratory performance. Here is the abstract of the report:
Successful bird migration can depend on individual learning, social learning, and innate navigation programs. Using 8 years of data on migrating whooping cranes, we were able to partition genetic and socially learned aspects of migration. Specifically, we analyzed data from a reintroduced population wherein all birds were capitve bread and artificially trained by ultralight aircraft on their first lifemtime migrations. For subsequent migrations, in which birds fly individually or in groups but without ultralight escort, we found evidence of long-term social learning, but no effect of genetic relatedness on migratory performance. Social learning from older birds reduced deviations from a straight-line path, with 7 years of experience yielding a 38% improvement in migratory accuracy.
The authors note more generally that in some bird species, "innate programs alone are not sufficient, and experiential learning is critical to successful navigation, as adult animals often have markedly better navigational capabilities than juveniles. Information transfer from more experienced individuals to inexperienced ones can be essntial to navigational success, especially for species that travel in groups. Current hypotheses, richly supported by theoretical studies, posit that social learning, coupled with interindividual coordination of movements, is esential to successful migration and the maintenance of group structure."
Whooping cranes, of course, are being bred in captivity because they are an endangered species. There is much to learn, also, from other species whose social structure is being altered by human impacts. The September 20 issue of Science
, interestingly, has a focus on recent changes in the behavior of species subject to hunting. Some cougar behavior, for instance, has changed in Washington State because in the 1990s, the state, under pressure from livestock owners, extended the hunting season on cougars and increased the number of cougars a hunter was allowed to take while also decreasing the cost of a hunting license. Cougar deaths have skyrocketed in Washington state--along with "complaints about problem animals." What has now become clear is that cougar society and therefore behavior is changing as a result:
[Wildlife] managers hadn't considered what happens to cougar society with such a high mortality rate. "A stable cougar society has senior, adult males," who patrol large territories and protect the kittens of several females, [WSU wildlife ecologist Robert] Wielgus explains. When a male dies, incoming younger males will fight over his territory, and kill kittens in order to bring the females into estrus again, as his team will report in Biological Conservation in November.
When the researchers looked at the cougar population of the Selkirk Mountains in eastern Washington, where lion complaints had increased, they discovered that most of the older male cats had been replaced by adolescent males. Because of the threat from these infanticidal young males, many of the female lions there had also moved to higher elevations with their cubs, Wielgus's team discovered. "The females moved to areas they would normally never use, where they eat prey they normally wouldn't eat, including the highly endangered mountain caribou," Wielgus says. The younger males also attacked livestock. "They're the ones that haven't learned to avoid people and so get into trouble."
The article also discusses alterations in bear and wolf behavior. It's all fascinating and thought-provoking. Nurture and education is
nature, and not some artificial additive outside of it. When will it become common sense to see that nature vs. nurture is a false dichotomy? I'd love to see more sf writers getting that one right.