Further notes on the natural history of the Ethiopian Bush-crow Zavattariornis stresemanni
The Ethiopian Bush-crow Zavattariornis stresemanni is a charismatic and Endangered endemic bird of southern Ethiopia, whose general biology remains under-studied. We present field notes and observations from 2008 to 2014, covering many aspects of the species’ behaviour and morphology. Bush-crows breed co-operatively in response to both of the local rainy seasons, but group size and fidelity of helpers appears to be variable. Bush-crow nests were found for the first time on man-made structures; a low power distribution pole and a tall electricity pylon. The display of one bush-crow to another is further described. Juveniles can be identified by darker coloration around the face, bright red gapes and distinctive begging calls. Adults possess lightweight, low-density body feathers and it appears that bush-crows have a moult phenology that overlaps extensively with breeding, a trait unusual in birds. Post-breeding dispersal is often limited, although anecdotal evidence and a handful of observations suggest that some individuals cover greater distances between breeding seasons. We report the first confirmed predation of a bush-crow, and supplement this with notes on other interspecific interactions. Finally, bush-crows were found for the first time north-west of Yabello (a small range extension), and we discuss the implications of local movements and range fluctuations in the context of the species’ apparent climatic range limitation.