Breeding Biology of SkylarksAlauda arvensisin Maize and Other Crop Fields

Abstract

Abstract. The Skylark populations are declining in most European agricultural landscapes. Changing crop compositions and seasonal vegetation dynamics have been suggested to influence the breeding success of Skylarks in arable fields. We quantified the breeding performance of Skylarks by means of continuous video surveillance in maize fields (n = 83 nests) and in a pooled sample of other crops, mostly sugar beet, opium poppy and cereals (n = 89 nests), in the Czech Republic, from 2009 to 2011. Skylarks colonized the bare ground of maize fields immediately after sowing and continued to breed there until the end of the breeding season in late July. The vegetation height at the time of laying did not exceed 100 cm, but late broods left nests under maize reaching up to 210 cm. In spite of similar clutch sizes, a lower number of chicks fledged per successful nest in maize fields compared to other crops, as a consequence of the lower hatchability and higher partial nestling mortality. Nest success (based on dail...