Remember a few years ago when a video of a bear stealing a dumpster from the back of a Colorado restaurant went viral? Most of us laughed: the idea that this short video represented a serious challenge surrounding disposal of our food waste never occurred to most of us. But a new post at Yale Environment 360 reviews recent science that shows wildlife becoming reliant on our leftovers is anything but funny or cute.
Richard Conniff rounds up several studies that show negative impacts of food waste on wildlife in a variety of ecosystems. Not only does the introduction of vast amounts of cast-off food alter the relationship between predators and prey in various environments, but it also creates reliance on this waste. “Subsidizing” animal diets creates all sorts of unforeseen consequences, but removing that food source could be equally problematic. For instance:
- The massive reduction of steelhead trout in California’s Monterey Bay over the past century may be partially a result of trash and fishery discards, according to a new study from Biologial Conservation. As one might expect, all of this “extra” food increases the population of Western gulls in the area, who also feed on young trout.
- A “superabundance” of yellow-legged gulls in the Mediterranean may account for all sorts of ecosystem damage, including increased predation pressure on other birds. What brought this gulls to this location? In part, increased levels of available food waste.
- We generally think of ravens as scavengers, but “they are also capable hunters,” according to an older study in Ecology. In the Mojave Desert, where common ravens are subsidized by human trash, researchers found these birds present additional threats to young desert tortoises.
- And food waste has been linked to increases presence of bears in Europe, and leopards in urban India.
Conniff points out successful efforts to curtain access of wildlife to food waste and trash – bears in the U.S.’s Yellowstone Park, for instance – but also notes that the increased reliance of many species on human cast-offs means that we can’t just remove these food sources.
This is fascinating: I’m as guilt as anyone as thinking of waste a primarily a resource availability issue. Conniff’s round-up shows that our relatively wanton disposal of edible waste creates all sorts of issues beyond inefficient use of materials, and irresponsible handling of products at the end of their useful lives.
Conniff’s post is definitely worth a read, as are the abstracts of the studies mentioned. Got thoughts to share? Do so…
Photo credit: Shutterstock