Global Ecology and Conservation (Aug 2023)
Facets of the nesting ecology of a ground-nesting bird, the Spotted Thick-knee, in an urban mosaic landscape
Abstract
Ground-nesting bird species are typically threatened when their natural habitats are removed or altered through urbanisation. Despite this, some species, like the Spotted Thick-knee (Burhinus capensis), persist in urban mosaic landscapes. Our study was undertaken to collect novel information on Spotted Thick-knee persistence in an urban mosaic landscape by investigating facets of its nesting ecology in Pietermaritzburg, South Africa. We collected Spotted Thick-knee nesting and nest site data between July 2019 and December 2020. We conducted direct observations at 33 nest sites, and additional remote monitoring with camera traps at eight nest sites. Spotted Thick-knee breeding pairs showed select habitat and nest-site preferences (greater use of shrub-like species for nest-site placement, more grass cover, shorter grass, and flatter slopes at nest sites) compared with random sites. Successful nesting outcomes were significantly greater than failed nesting outcomes. Incubation activity was significantly longer during the day, and incubation activity had a significant adverse relationship with disturbance in human-modified habitats. Land use and human activity influenced nest-site selection and survival of nests. Spotted Thick-knee used residential gardens and recreational areas as nest sites in the urban mosaic, although nests were more successful in residential gardens. They used shrub-like vegetation as nest-cover structures, possibly because of added protection from extreme weather or less visual detection. Risks associated with nesting in human-modified habitats included increased threats from domestic animals and incubation activity costs because of disturbance around nest sites. There are relatively few studies on ground-nesting birds in urban areas, so further research is needed to determine how our results compare with other species.
