Human food sources tempt migratory bears to stay put

An international team of researchers studying brown bears in Sarıkamış Forest Allahuekber Mountains National Park (SANMP) in northeast Turkey have uncovered some surprising behaviors. Most notably, the ready availability of human food waste has caused some Turkish bears to give up migration in favor of a life of dumpster diving.

The fact that these brown bears were migrating in the first place is unusual in and of itself. Other bear species, particularly polar bears, migrate. But that behavior has never been observed in brown bears. According to the authors, the bears shouldn’t need to migrate in an undisturbed ecosystem. However, in this heavily used Scots pine forest that lacks nuts and fruits in the understory, they may need to travel further afield for food. Indeed, when the researchers captured and collared 16 bears and tracked them between 2012 and 2014, they found that six bears made long-distance migratory trips of up to 166 kilometers roundtrip, lasting up to 72 days.

The other 10 bears, however, opted out of migration. Instead, they led a more sedentary lifestyle, making short nighttime jaunts to feed on food scraps at an unfenced dump on the outskirts of the nearby city of Sarıkamış, population 18,000.

What’s more, that dump is slated to be closed, putting both the bears and city residents in a tight spot. While the dump bears could starve, or begin migrating like their counterparts, the researchers suspect that they’ll instead attempt to exploit other anthropogenic food sources by moving deeper into the city, at least in the short term. That, in turn, is likely to increase conflicts with people, which too often result in the killing of so-called problem animals. In anticipation of the dump’s closing, the researchers recommend that locals begin habitually using bear-proof trash bins and removing leftovers and table scraps from households daily. In the longer term, the viability of this bear population depends on having enough connected forested habitat to protect their migration pathways.

The story of the Sarıkamış bears is hardly unique. Hyenas in Ethiopia rarely come into conflict with humans because instead of hunting livestock (or small children), they feast upon discarded hunks of meat and dissected carcasses from veterinary schools. Some white storks in Spain and Portugal have given up migrating to Africa each year because they can find everything they need in local landfills. And some researchers think that wolves began their long evolutionary road towards becoming domesticated dogs by spending time gobbling up our leftovers. As humans share more habitat with animals, we may increasingly find that they’re becoming less and less wild. – Jason G. Goldman | 29 June 2016

Source: Cozzi, G., Chynoweth, M., Kusak, J., Çoban, E., Çoban, A., Ozgul, A., & Şekercioğlu, Ç. H. (2016). Anthropogenic food resources foster the coexistence of distinct life history strategies: year-round sedentary and migratory brown bears. Journal of Zoology. DOI: 10.1111/jzo.12365.

Header image: A mother bear with her three cubs at the Sarikamis garbage dump. Via Karla Garcia, used with permission.