Once a haven for breeding shorebirds worldwide, nest predation in the Arctic has been on the rapid rise, putting global populations at increased risk, according to a new report. The results suggest that disruptions in historic patterns of predator and prey are driven by global climate change. The survival of baby birds is critically important in maintaining wild populations. Extreme rates of nest predation can lead to serious population declines and an increased risk for extinction. Historically, predation rates for birds that breed nearer to the equator are higher than those for birds who breed nearer to the poles. As a result, many birds have adapted strategies to ensure the survival of their offspring, including migrating thousands of miles, away from the tropics, to rookeries in Arctic areas. However, previous research has suggested that climate change is likely to impact individual animals in a variety of ways, including species interactions, such as those between predator and prey. These interspecies effects are not well-understood, however, and have not been assessed on a global scale. Here, Vojt?ch Kubelka and colleagues explore the global impacts of climate change on patterns of nest predation by assembling a database of over 38,000 individual shorebird nests from 237 populations. They report that overall rates of nest predation have been on the rise for the last 70 years. Furthermore, Kubelka et al. discovered that in recent years, shorebird nest predation rates in the Arctic have significantly eclipsed those in the tropics - increasing two-fold in northern temperate zones and three-fold in the Arctic - reversing the long-standing historic latitudinal gradient of predation. Further analysis suggests that the higher rates of predation are likely associated with increases in ambient temperatures and temperature variations, which could be the cause of observed declines in shorebird populations overall, according to the authors.
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Journal
Science