Selection of breeding territory by little bustard (Tetrax tetrax) males in Central Spain: the role of arthropod availability

Abstract

The influence of arthropod availability on the formation of male little bustard breeding territories in central Spain was studied in two consecutive years. Arthropods (68,217 individuals) were sampled using pitfall trapping and male territories estimated by means of kernel functions. Hymenopterans (ants), beetles, mites and spiders were the main taxa found in the samples, while the highest contributions in terms of biomass came from hymenopterans, beetles and orthopterans. The only group that exhibited significant biomass differences between territory and non-territory locations was that of the beetles; this pattern was consistent between years. Carabidae was the main beetle family in terms of biomass, followed by other large beetles such as Tenebrionidae, Cleridae, Scarabeidae and Elateridae. The biomass of Carabidae that were larger than 15 mm was significantly higher within territories than outside them. The biomass of Cleridae was greater in fallows, while Elateridae were more abundant in arable fields. The total biomass of beetles that were larger than 15 mm was higher in arable fields than in fallows. Family richness differed between years, while diversity showed differences between agricultural fields (it was highest in fallows), although these variables did not differ between territory and non-territory locations. Results indicate that large beetles (particularly carabids) seem to be a valuable food resource that is defended by little bustard males during the highly energy-demanding breeding season, which is discussed here in relation to habitat selection, the mating system and its implications for the conservation of the species.

Fallow management increases habitat suitability for endangered steppe bird species through changes in vegetation structure

“…Little Bustard males benefited from the restrictions in vegetation height but not in vegetation cover provided by Shredding, probably due to their conflicting needs of visibility for displaying and courtship, and significant cover of short green plants for feeding (Morales et al, ). Agricultural practices did not affect LB male occurrence through food availability despite its known preferences for food‐rich territories to afford the costs of mating activities (Faria, Rabaça, & Morales, ; Traba, Morales, García dela Morena, Delgado, & Krištín, ). This finding may be reasonable for this species, because unploughed FFs and moderate management (e.g.…”

The role of fallow in habitat use by the Lesser Kestrel during the post-fledging period: inferring potential conservation implications from the abolition of obligatory set-aside

“…Arthropod species, mainly Orthoptera, are known to be the main part of Lesser Kestrel's diet during the post-fledging period (Franco and Andrada 1977;Tejero et al 1982;authors unpublished data). Many studies have shown that higher diversity and abundance of arthropods are associated with these habitats in the farmed landscape not only during summer (e.g., Tellería 1988;Henderson et al 2000a) but also during other seasons (e.g., breeding season, Rodríguez et al 2006;Traba et al 2008). Moreover, these habitats presumably are suitable for foraging because they have short vegetation (Henderson et al 2000b;Rodríguez et al 2006, authors, unpublished data) providing good prey accessibility (García et al 2006;Rodríguez et al 2006, authors, unpublished data), and hunting areas (unpublished data).…”

“…Fallow has been proved to be a preferred habitat for foraging in other farmland birds during summer (Henderson et al 2000a;Henderson et al 2000b), including many endangered species [e.g., Great Bustard Otis tarda (Moreira et al 2004), Little Bustard Tetrax tetrax, and Black-bellied Sandgrouse Pterocles orientalis (Delgado and Moreira 2000)]. Fallow is a particularly important habitat for farmland birds and, according to other studies, for other taxonomic groups (e.g., weed seeds, plants and invertebrates; see Henderson et al 2000a;Henderson et al 2000b;Van Buskirk and Willi 2004;Traba et al 2008), acting like reservoirs of farmland biodiversity.…”

The importance of grazing regime in the provision of breeding habitat for grassland birds: The case of the endangered little bustard (Tetrax tetrax)

“…Verdú et al (2000) pointed out that controlled traditional grazing in Mediterranean pseudo-steppes is an important measure to favour vegetation and arthropod diversity. The selection of lightly grazed areas may suggest an access to high-quality habitats where vegetation structure and diversity support a diverse arthropod community including favourite and profitable arthropods for the species (see Jiguet 2002;Traba et al 2008).…”