First records of predation of grey long-eared bats (Plecotus austriacus) by the barn owl (Tyto alba) in the Netherlands

The Dutch National Ecological Monitoring scheme (NEM) is analysing owl pellets, predominantly from barn owl (Tyto alba) in order to monitor small mammals (rodents and shrews). Barn owls and bats, most frequently long-eared bats (brown long-eared bat (Plecotus auritus) and grey long-eared bat (Plecotus austriacus) both roost in the lofts of churches, monasteries, old farmhouses etc., and it is known that these bats are occasionally predated by barn owls (Bekker & Mostert 1991, Swift 1998). In the Netherlands grey long-eared bats are only found in the south of the country (in the provinces of Limburg, Noord-Brabant and Zeeland), which are the north-western limits of the species’ range. Before now grey longeared bats have never been recorded in owl pellets in the Netherlands. This short paper reports on the first known occurrence of barn owl predation of a grey long-eared bat in the Netherlands. In 1997 skulls of three grey long-eared bats were found in barn owl pellets from a church in Diepenbeek (in Belgium, 25 kilometres west of the city of Maastricht). This batch, of more than 2700 prey items also contained two serotines (Eptesicus serotinus) and high percentages of birds (around 120) and amphibians (more than 100) (Wout Willems, Natuurpunt, personal correspondence). There are records from other European countries of the skulls of grey long-eared bats being found in the pellets of barn owls: in Poland in the 1970s, 1980s and 1986 (Ruprecht 1979, Lesinski 1989 and Kowalski & Lesinski 1988 respectively) and Spain in the 1980s and in 2003 (the latter in Ibiza) (Perez Barberia 1991 and Sommer et al. 2005 respectively). In the Netherlands barn owls are known to predate on the brown longeared bat and other bat species, mainly roosting in buildings (Bekker & Mostert 1991, Huizenga et al. 2010).