The genetic structure of the European breeding populations of a declining farmland bird, the ortolan bunting (Emberiza hortulana), reveals conservation priorities

• Published in: Conservation Genetics
• Main Authors: Moussy, Caroline, Arlettaz, Raphaël, Copete, José Luis, Dale, Svein, Dombrovski, Valery, Elts, Jaanus, Lorrillière, Romain, Marja, Riho, Pasquet, Eric, Piha, Markus, Seimola, Tuomas, Selstam, Gunnar, Jiguet, Frédéric
• Other Authors: Centre d'Ecologie et des Sciences de la COnservation (CESCO), Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Universität Bern / University of Bern (UNIBE), Institut de Systématique, Evolution, Biodiversité (ISYEB ), Muséum national d'Histoire naturelle (MNHN)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Umeå University, Sweden
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: Endangered species; Gene flow; Genetic diversity; Long-distance migrant; [SDV.GEN.GA]Life Sciences [q-bio]/Genetics/Animal genetics; [SDV.GEN.GPO]Life Sciences [q-bio]/Genetics/Populations and Evolution [q-bio.PE]; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Fennoscandia
• Online Access: https://hal.science/hal-03766836; https://hal.science/hal-03766836/document; https://hal.science/hal-03766836/file/HAL_Moussy%20et%20al.%20-%202018%20-%20Conservation%20Genetics%20-%20The%20genetic%20structure%20of%20the%20European%20breeding%20populations%20of%20a%20declining%20farmland%20bird,.pdf; https://doi.org/10.1007/s10592-018-1064-9

International audience Anthropogenic activities, such as agricultural intensification, caused large declines in biodiversity, including farmland birds. In addition to demographic consequences, anthropogenic activities can result in loss of genetic diversity, reduction of gene flow and altered genetic structure. We investigated the distribution of the genetic variation of a declining farmland and long-distance migratory bird, the ortolan bunting Emberiza hortulana, across its European breeding range to assess the impact of human-driven population declines on genetic diversity and structure in order to advise conservation priorities. The large population declines observed have not resulted in dramatic loss of genetic diversity, which is moderate to high and constant across all sampled breeding sites. Extensive gene flow occurs across the breeding range, even across a migratory divide, which contributes little to genetic structuring. However, gene flow is asymmetric, with the large eastern populations acting as source populations for the smaller western ones. Furthermore, breeding populations that underwent the largest declines, in Fennoscandia and Baltic countries, appear to be recently isolated, with no gene exchange occurring with the eastern or the western populations. These are signs for concern as declines in the eastern populations could affect the strength of gene flow and in turn affect the western populations. The genetic, and demographic, isolation of the northern populations make them particularly sensitive to loss of genetic diversity and to extinction as no immigration is occurring to counter-act the drastic declines. In such a situation, conservation efforts are needed across the whole breeding range: in particular, protecting the eastern populations due to their key role in maintaining gene flow across the range, and focussing on the northern populations due to their recent isolation and endangered status.