An inter‐regional approach to intraspecific variation in habitat association: Rock Buntings Emberiza cia as a case study

Abstract

The habitat association approach has been increasingly used in ecology to resolve problems in wildlife conservation and management. One problem related to habitat association studies is that they are restricted to small geographical areas within a species’ range, and thus they are applicable to only a limited set of environmental conditions utilized by the species. In addition, very few studies address why the preference for specific habitat components may be adaptive for the species in question. The objective of this study was to examine how consideration of populations of a species from two dramatically different environments affects the results of habitat association modelling for a ground‐nesting passerine, the Rock Bunting Emberiza cia. At a regional scale, a trend to defending breeding habitat patches with relatively higher stone cover was confined to birds from a temperate region in Slovakia. In contrast, in a semi‐arid region in southeastern Spain, Rock Buntings preferred to use breeding habitat patches that had relatively higher grass cover. Combining data from both regions, breeding Rock Buntings showed a general pattern of using habitat patches close to hedges, with low bush cover, high ditch density and a steep slope. Whereas regional habitat association models appear to be sensitive to the particularities of the breeding environment, our study suggests that Rock Bunting breeding habitat association is constrained by the adults’ tactics to protect themselves against predators. Although the birds prefer to nest in patches of low vegetation, the better to see nearby predators, these patches are ideally close to taller vegetation that can be used to provide cover when evading predators, and they are also of a rugged profile that helps the birds to approach and leave the nest stealthily.

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

“…Moreover, the patches with steeper slopes and soil heaps also are more prone to soil erosion which may in turn increase the surface of bare ground and thus provide suitable foraging habitats for Ortolan Buntings (Brambilla et al 2016; and see below). Alternatively, the elevated posts may facilitate predator detection from longer distances (Sánchez et al 2009).…”

“…This approach is a standard methodological procedure in determining species habitat associations (e.g. Šálek et al 2014, 2016a) and was successfully applied earlier in studies on Ortolan Buntings (Berg 2008, De Groot et al 2010, Morelli 2012) and other bunting species (Whittingham et al 2005, Sánchez et al 2009) in various European landscapes. We determined the centre of the occupied site as the exact male singing post or where any signs of the breeding behaviour (e.g.…”

“…We determined the centre of the occupied site as the exact male singing post or where any signs of the breeding behaviour (e.g. alarm calls, birds carrying nesting material) were recorded (see also Berg 2008, Sánchez et al 2009). If singing posts of singing males were less than 100 m apart during subsequent field visits, we treated this as one individual/pair and chose the middle point for the territory (Dale and Olsen 2002, Sánchez et al 2009).…”

“…alarm calls, birds carrying nesting material) were recorded (see also Berg 2008, Sánchez et al 2009). If singing posts of singing males were less than 100 m apart during subsequent field visits, we treated this as one individual/pair and chose the middle point for the territory (Dale and Olsen 2002, Sánchez et al 2009). Two individual territories that were closer than 100 m were only considered if individual males were heard singing simultaneously.…”

Effect of Transhumant Livestock Grazing on Pseudo-Alpine Grassland Bird Communities

“…Bird community in NGG showed a great separation from those in both grazed grasslands with two species, the Rock and the Corn Bunting, highly confined to those areas. The Rock Bunting was observed only in NGG and was probably favored by the presence of shrubs and the rock cover, which are important territory components of the species [74]. Moreover, the Corn Bunting seemed to benefit from the presence of shrubs [75,76] in grasslands with absence of grazing.…”