The argument that humans are evolutionarily maladapted to urban lifestyles and fast food finds support in a report that black bears are becoming fat and lazy from eating junk food from dumpsters.
NEW YORK (Nov. 24) -- Black bears living in and around urban areas are up to a third less active and weigh up to thirty percent more than bears living in wild areas, according to a recent study by scientists from the Bronx Zoo-based Wildlife Conservation Society (WCS).
The study, published in the latest issue of the Journal of Zoology says that black bears are spending less time hunting for natural food, which can consist of everything from berries up to adult deer. Instead, they are choosing to forage in dumpsters behind fast-food restaurants, shopping centers, and suburban homes, often eating their fill in far less time than it would take to forage or hunt prey.
"Black bears in urban areas are putting on weight and doing less strenuous activities," said WCS biologist Dr. Jon Beckmann, the lead author of the study. "They're hitting the local dumpster for dinner, then calling it a day."
In addition, the authors say that urban black bears are becoming more nocturnal due to increased human activities, which bears tend to avoid. Bears are also spending less time denning than those populations living in wild areas, which the authors say is linked to garbage as a readily available food source.
The authors suggest that as humans continue to expand into wild areas, and as bears colonize urbanized regions, people must be educated to reduce potential conflicts. Local ordinances should be passed mandating bear-proof garbage containers for homes and businesses. "Black bears and people can live side-by-side, as long as bears don't become dependent on hand-outs and garbage for food," Beckmann said. "Lawmakers should take a proactive stance to ensure that these important wild animals remain part of the landscape."
This change in environment is a selective pressure. While is it not clear what traits are being selected for in bears by urban environments it seems very likely that different traits are being selected for among urban bears than among bears that live out in the wild.
Update: I know what you are all thinking: In the face of the rising obesity of our inner city black bear population no government agencies or health professionals are taking steps to encourage the urban black bears to come to cholesterol screening clinics to see if their junk food diets are putting them at risk for heart disease. Even if they come to the clinics they have no medical insurance that includes a prescription drug benefit to pay for Lipitor. Something must be done. Also, are any black bears getting screening for type II diabetes? And who, if anyone, is giving them dietary advice? They need nutritional counseling and they should be on a diet high in fiberous nuts and berries. Shouldn't the junk food industry be taxed for making cheap high calorie meals so easily available in dumpsters?
|Share |||Randall Parker, 2003 November 25 02:30 AM Evolutionary History|