Environmental and social constraints on breeding site selection. Does the exploded‐lek and hotspot model apply to the Houbara bustardChlamydotis undulata undulata?

Abstract

Habitat selection is a hierarchical process where the distribution of individuals is constrained by environmental factors acting from the landscape scale to specific microhabitats such as breeding sites. However, interactions between conspecifics might greatly influence bird distribution and habitat use, especially in lekking birds. In the lekking Houbara bustard Chlamydotis undulata undulata, we investigated the respective role of environmental and social constraints on the distribution of nests and display sites. We measured environmental variables around 69 nests and 70 display sites at different spatial scales: the landscape, the breeding range, and the display and nest site scale. The variables were compared to those measured at 50 random plots to determine whether environmental features are actively selected. Social variables were included by studying spatial relationships between displaying male density, nests and female movements throughout the year. At the landscape scale, human presence acted as a limiting factor for the establishment of nest and display sites. At the breeding range scale, habitat requirements differed between sexes. Breeding females used a heterogeneous complex of habitats provided by the network of wadis (water courses) crossing the reg (gravel plain) covered by tall perennial plants. In contrast, display males looked for conspicuousness and courtship ability by selecting the reg with short perennials, and used temporarily flooded areas for feeding. Males aggregated on traditional display site where they experienced the greatest female density. This result supported the hotspot model in the evolution of leks in the Houbara bustard. It underlies an overriding effect of female attraction on male settlement in the individual habitat selection process.

Effects of habitat and land use on breeding season density of male Asian Houbara Chlamydotis macqueenii

“…However, this is the first study to show how vertical vegetation structure can influence houbara numbers at a landscape scale. With the exception of Carrascal et al (2008), other studies have not considered shrub height, possibly due to the huge effort needed to robustly collect such data (van Heezik and Seddon 1999;Yang et al 2002a;Hingrat et al 2008;Chammem et al 2012). A study by Carrascal et al (2008) did not find an influence of shrub height; however, this compared mean shrub height at presence versus absence sites across a range of suitable and unsuitable habitats, dominated by short vegetation and, therefore, other features, such as sandy substrate, were more influential at this scale of analysis.…”

“…Several studies have related land use factors to density and distribution of resident African Houbara C. undulata across its range, and indicated that breeding birds are negatively affected by direct and indirect human disturbance, avoiding settlements, major roads, wells, shepherds' camps and agricultural fields (Carrascal et al 2006(Carrascal et al , 2008Hingrat et al 2008;Chammem et al 2012). In contrast, a study in Iran showed wintering Asian Houbara were associated with croplands (Aghainajafi-Zadeh et al 2010), while breeding season distribution of male Asian Houbara was not found to be influenced by pastoralism in Uzbekistan (Koshkin et al 2014).…”

Consistent nest-site selection across habitats increases fitness in Asian Houbara

“…have also reported selection for more screened sites, with African Houbara (C. undulata) laying their eggs closer to a shrub than random sites (Hingrat et al 2008) and anecdotal evidence from Pakistan similarly indicating that Asian Houbara frequently place nests near a taller shrub (Mian 1998). Despite this clear female preference, placing the scrape in a well-concealed position had no effect on nest survival.…”

“…Previous studies addressing fine-scale habitat selection of nesting houbara species (Chlamydotis spp.) have highlighted the importance of vegetation structure for nest-site selection, generally involving low, sparse vegetation (Yang et al 2003, Hingrat et al 2008, Aghanajafizadeh et al 2012. However, drawing comparisons between these studies is problematic because they…”

Effects of habitat and livestock on nest productivity of the Asian houbara Chlamydotis macqueenii in Bukhara Province, Uzbekistan

“…In Israel, expert opinion has suggested that livestock grazing negatively impacts nest success through disturbance (Lavee 1988), and in Morocco, livestock concentrations may restrict African houbara access to suitable areas (Le Cuziat et al 2005b). In Morocco and Fuerteventura, breeding African houbaras avoid major roads, human settlements and sheep camps (Carrascal et al 2008;Hingrat et al 2008;Le Cuziat et al 2005a), but whether productivity is influenced by these anthropogenic factors has not been examined. Although the numbers and distribution of male houbara showed no response to low and moderate sheep densities in the southern Kyzylkum, Uzbekistan (Koshkin et al 2014(Koshkin et al , 2016, livestock impacts on nesting are unknown.…”