A new study reveals that shoreline development in northern Poland, long considered a destructive force, is actually helping shoreline-nesting birds by protecting them from an invasive species. The human development deters the invasive American mink, protecting the native shorebirds from otherwise-overwhelming predation.
“‘The Mazurian Lakeland, in northeastern Poland, has been recognized as an important region for many bird species,” a research team notes in Biological Conservation. And until the mid-1980s, waterfowl – including the great crested grebe, (Podiceps cristatus), and the coot (Fulica atra) – nested in droves. In 1984, however, “the first invasive American mink (Neovison vison) was observed in this region, and over the following years the feral mink population increased rapidly.” Soon, researchers began to see noticeable population declines and changes in nesting patterns among the waterfowl – not surprising, given the mink’s appetite for eggs. Coot alone declined by 20-fold in some places.
To better understand the shifts, the researchers carefully analyzed more than a decade’s worth of breeding bird surveys and mink abundance studies done at dozens of regional lakes. They found that mink densities varied from 1.0 to 14.6 individuals per 10 kilometers of shoreline. They were also able to figure out how big a threat the mink posed to eggs, by building artificial nests filled with chicken eggs. Overall, “mink were responsible for the losses of 17–58% of [the] experimental clutches.'”
Read the full article at Conservation Magazine.
