Seed depletion and landscape structure affect aggregative response in two wintering passerine birds

• Published in: Bird Study
• Main Authors: Powolny, Thibaut, Eraud, Cyril, Lerest, Kévin, Bretagnolle, Vincent
• Other Authors: Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté COMUE (UBFC)-Université Bourgogne Franche-Comté COMUE (UBFC), Avifaune Migratrice (CNERA), Office National de la Chasse et de la Faune Sauvage, Office Nationale de la chasse et faune sauvage (ONCFS), ONCFS, Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: [SDE]Environmental Sciences; Alauda arvensis
• Online Access: https://hal.science/hal-01849633; https://doi.org/10.1080/00063657.2017.1414144

International audience Capsule: Seed abundance but also seed depletion during winter modifies habitat use and aggregation behaviour of Eurasian Sky Lark Alauda arvensis and Meadow Pipit Anthus pratensis.Aims: To investigate the effect of seed abundance on the density of two passerine birds, the Eurasian Sky Larks and the Meadow Pipit, at an agricultural landscape scale during winter.Methods: Bird counts as well as seed density measurements were carried out in winter to quantify the aggregative response of farmland birds to seed abundance from November to March.Results: Seed resources varied by a factor of ten between crop types, but declined so sharply over the winter that seed abundance was low and similar among crop types by late winter. Sky Larks selected for higher seed density plots, but only at the end of winter when the resources were the lowest. Conversely, Meadow Pipits did not show any aggregative response to seed abundance.Conclusion: These results show that an uptake of seed-rich habitats in agricultural landscape would be very beneficial for wintering granivorous birds, by fulfilling the late winter ‘hungry gap’. The inclusion of seed mixtures in habitats that attract high densities of birds and retain seeds until late winter is of primary interest.