Breeding prerequisites for Ortolan Bunting Emberiza hortulana in Swedish farmland with special focus on foraging

Ortolan Buntings Emberiza hortulana are rapidly decreasing in Sweden. Changes in agricultural practices are the main reason. Landscape simplification due to the removal of semi-natural elements leads to a lack of breeding habitats. Furthermore, due to intensive artificial fertiliser applications and advanced agricultural equipment and technology, crops grow both taller and denser than 50 years ago. In Kvismaren, south central Sweden, Ortolan Buntings have been studied since 2009. Here, we focus on one question: what defines a good foraging microhabitat? In 2017, nesting areas for five females and four males were identified and we did 271 feeding observations. Average foraging distance at different nests varied between 47 and 114 meters. About 70% of the foraging activities took place within crop fields. Ortolans utilized mainly unsown rows, later to be used by tractors for spraying etc. and patchy parts of standing crops. Invertebrates extracted from those areas looked dark, suggestive of ground-dwelling species. Our key management recommendation to create better microhabitats for feeding can be easily achieved by most farmers: to leave two unsown sowing rows (amounting to 0.38 m in width) for each tractor wheel to follow.

Unravelling migration connectivity reveals unsustainable hunting of the declining ortolan bunting

In France, illegal hunting of the endangered ortolan bunting Emberiza hortulana has been defended for the sake of tradition and gastronomy. Hunters argued that ortolan buntings trapped in southwest France originate from large and stable populations across the whole of Europe. Yet, the European Commission referred France to the Court of Justice of the European Union (EU) in December 2016 for infringements to legislation (IP/16/4213). To better assess the impact of hunting in France, we combined Pan-European data from archival light loggers, stable isotopes, and genetics to determine the migration strategy of the species across continents. Ortolan buntings migrating through France come from northern and western populations, which are small, fragmented and declining. Population viability modeling further revealed that harvesting in southwest France is far from sustainable and increases extinction risk. These results provide the sufficient scientific evidence for justifying the ban on ortolan harvesting in France.

Den andra kända observationen av polygyni hos ortolansparv Emberiza hortulana

During field work on foraging of the Ortolan Bunting Emberiza hortulana in a small and isolated population at Kvismaren in the county of Örebro in south Sweden, two females, nesting 1,250 m apart were observed to be mate-guarded by the same colour-ringed male. Although the male commuted between the nests, none of the females seemed to obtain any substantial help from him when feeding the young. Polygyni has been reported only once before in this species, namely seventy-five years ago, also in a small population in Sweden, when a male behaved in a similar manner to that that we observed at Kvismaren.

Habitat selection of an endangered European farmland bird, the Ortolan Bunting Emberiza hortulana, in two contrasting landscapes: implications for management

SummaryEffective conservation measures for any bird species across their distribution ranges require detailed knowledge of landscape-specific differences in habitat associations. The Ortolan Bunting Emberiza hortulana is a farmland bird species, which experienced massive population declines during the recent decades and has become a conservation priority in many European countries. Thus, identification of the key habitat features is an important prerequisite for the conservation of the species. Here we investigate habitat associations of the Ortolan Bunting for the remaining breeding population of the species in the Czech Republic. This population is remarkable by its distribution in two markedly different environments – farmland and post-mining landscapes. The main objectives of this study were to identify habitat features associated with Ortolan Bunting occurrence within the two contrasting landscapes and at two spatial scales. Our results reveal a high degree of habitat plasticity by Ortolan Buntings in the Czech Republic which was revealed by the landscape- and scale- specific habitat associations. Habitat heterogeneity, in terms of compositional and configurational diversity, and the cover of bare ground were the most important predictors of Ortolan Bunting occurrence in both landscape types. In farmland, the species occurrence was positively associated with shrub and woody vegetation, poppy fields and set-asides, and negatively associated with grasslands, gardens/orchards, seedlings and urban habitats. In the post-mining landscape, the cover of herb vegetation and greater slope steepness and terrain ruggedness were most important habitat features. Ortolan Buntings in the post-mining landscape appear to avoid patches with a higher cover of shrub and woody vegetation, forests, seedlings and urban areas. We propose that conservation measures for Ortolan Buntings should focus on enhancing farmland habitat heterogeneity, but also on regulating the rate of succession in disturbed environments, such as post-mining landscapes.