Does habituation to humans influence predator discrimination in Gunther's dik-diks (Madoqua guentheri)?

Animals living around humans may habituate to us, but little is known about the consequences of this habituation. Some wildlife managers assume that habituation to humans makes individuals less likely to respond to natural predators, which is something to be avoided in captive breeding programmes where animals are destined for release. We conducted a playback experiment where we broadcast the sounds of a terrestrial predator and the song from a non-threatening bird to Gunther's dik-diks (Madoqua guentheri), a small ungulate that is vulnerable to many predators, in areas where dik-diks were and were not habituated to humans. Contrary to our expectation, habituated dik-diks discriminated the predator sounds from the birdsong, while unhabituated dik-diks failed to make this discrimination. Our results demonstrate that humans may influence predation hazard assessment, but we should not generally assume that human-habituated animals will be especially vulnerable to predators.