Do sheep affect distribution and habitat of Asian Houbara Chlamydotis macqueenii?

摘要

We examined whether pastoralism affected the distribution of Asian Houbara Bustard Chlamydotis macqueenii (IUCN Vulnerable) or modified its habitat across 14,500 km~2 of the Kyzylkum Desert, Uzbekistan. In this landscape, sheep grazing is constrained by access to water, allowing effects to be examined independent of topography and vegetation community. Across a gradient of sheep density (0-10 to 30-80 individuals km~(-2)) we achieved n = 140 10-km driven transects (total driven 3500 km). On all transects Houbara and sheep were surveyed at least once, and 96 were driven three times with vegetation sampled on four 50 m-long transects along each of these (measuring 7493 shrubs). Houbara distribution and abundance was also recorded at 147 point counts. In Generalised Linear Models that controlled for plant community, neither interpolated sheep density (within 1 km buffers) nor topographic variation affected houbara incidence on transects, or incidence and abundance at point counts. Although subtle effects were found for some palatable shrubs, sheep did not strongly modify shrub composition or structure at landscape scales. At landscape-scales, livestock browsing has not widely degraded these rangelands, which appear sustainably managed or even under-utilised. Pastoralism and houbara conservation may therefore be compatible, although impacts on nesting females require investigation.