Living in seasonally dynamic farmland: The role of natural and semi-natural habitats in the movements and habitat selection of a declining bird

Abstract

Understanding spatiotemporal variations of movements and habitat selection by animals living in changing, heterogeneous environments under increasing human pressure is crucial for biodiversity conservation. We report here on shifts in habitat selection and movements during the breeding and non-breeding periods in a vulnerable and specialist bird, the pin-tailed sandgrouse Pterocles alchata, to understand the importance of remnant natural or semi-natural habitats. We used a 7-year dataset from 91 radio-tracked birds living under two contrasting landscapes: a farmland-dominated area (agricultural landscape) in central Spain and a low-intensive farmland area with natural steppe-like vegetation (mixed landscape) in northern Spain. We found that sandgrouse selected sites of natural vegetation (short shrubs and sparse annual plants) across all periods in the mixed landscape. Birds performed long movements in the agricultural landscape to exploit patchy resources and expanded their distribution during the breeding period, possibly because of an increased scarcity of non-cropped habitats in farmland. During the non-breeding period, sandgrouse used dry arable lands in both landscapes, with birds in the mixed landscape displaying a highly mobile pattern to visit dry arable regions. Dry arable lands become structurally more suitable during winter for seed-eating birds such as sandgrouse that can use ploughed fields and exploit seeds during cereal sowing. Effective conservation measures for specialist birds of farmland should promote a greater availability of non-cropped habitats of natural and semi-natural vegetation to enhance their space use and reproductive opportunities.