杏吧原创

Bigfoot’s likely haunts ‘revealed’

A tongue-in-cheek study based on sightings of the mythical Sasquatch is a warning to ecologists that they shouldn't make too many assumptions about species habitats
Bigfoot habitat seems to match that of the brown bear. More than a coincidence?
Bigfoot habitat seems to match that of the brown bear. More than a coincidence?
(Image: AMBLIN/UNIVERSAL/THE KOBAL COLLECTION)

Sasquatch, the mythical 鈥淏igfoot鈥 of western North America, makes its home deep within the fertile imaginations of gullible people. If you insist on looking for one in the real world, though, you should search in the home of the black bear 鈥 at least according to a tongue-in-cheek study of the ape-like creature鈥檚 habitat preferences.

The study has a more serious message too: it鈥檚 easy to be fooled into believing a plausible-looking habitat analysis, even when the data is totally erroneous.

Conservation biologists often need to predict where rare species are capable of living 鈥 for selecting the best site for a national park, for example, or forecasting how badly a species鈥 range will suffer as the climate changes in the future.

The latest technique for making these predictions is so-called , in which researchers log the locations of known species sightings, then gather environmental data for those places to define the ecological limits of the species鈥 range.

, an entomologist at the University of Illinois at Urbana-Champaign, was worried that some people may have been too uncritical in applying the technique. 鈥淲henever you have these new, shiny, easy-to-use approaches, there鈥檚 a temptation to use them even before you know what the kinks are,鈥 he says.

Bear facts?

So Lozier and his colleagues decided to apply ecological niche modelling to an obviously false data set 鈥 Sasquatch sightings. They gathered all reported sightings in the US states of Washington, Oregon and California and used the environmental data to predict Sasquatch distribution.

They found that the model yielded a perfectly plausible prediction about Bigfoot habitats 鈥 a warning to modellers that spurious results will not necessarily announce themselves through obvious warning signs

鈥淭he point of the paper is really well taken,鈥 says , an evolutionary ecologist at the University of California at Davis who is an expert in ecological niche models. 鈥淚 think the literature is rife with people who are over-interpreting what comes out of these models.鈥

The researchers also compared the niche model for Sasquatch to one they developed for black bear. The two were statistically indistinguishable, they found. This suggests that many supposed Sasquatch sightings may simply be misidentified bears 鈥 a mistake that has been made on at least one occasion, Lozier notes.

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Topics: Ecology