Abstrakt
Nest predation is a common cause of breeding failure with direct consequences for the regulation of bird populations. Recently concerns have been raised about increased nest predation in populations of shorebirds.
At the same time some large gaps in geographic coverage of studies on nest predation have been identifed. To extend our knowledge on nest predation rates for previously unexplored areas, we investigated shorebird colonies at steppe lakes near Astrakhan (Russia) during 10 days in May 2017.
We also studied solitary nesting Kentish Plover Charadrius alexandrinus during 2006-2009 and 2016-2018 at Elton Lake in the Volgograd region, 300 km north of Astrakhan. The pilot data in Astrakhan indicate exceptionally high daily nest predation rates (0.106) in 59 nests of seven shorebird species at fve localities.
Focussing on the three most abundant species, 96% of Black-winged Pratincole Glareola nordmanni, 92% of Black-winged Stilt Himantopus himantopus and 98% of Pied Avocet Recurvirostra avosetta nests were predated. For Kentish Plover at Elton Lake, similarly high daily (0.131) and total (98%) nest predation rates (28 nests) were found.
Our results suggest that shorebirds breeding in natural steppe lakes could experience exceptionally high nest predation rates, but our sample sizes were low. Further studies from this region are needed to fnd out whether the high nest predation rates we found were seasonally or locally restricted anomalies, or whether it is a widespread phenomenon with possible consequences for the population dynamics of shorebirds in this region