Bucks make call judgement
Researchers have found that fallow deer bucks make judgements about the possible threat from competitors from the sound of their calls during mating season.
During the deer’s breeding season researchers, from UK’s Queen Mary University of London and Switzerland’s ETH Zürich, played a variety of different calls that had been digitally manipulated to change the pitch and length and analysed their responses to male fallow deer in a park in West Sussex, southern England. The experts found that the bucks treated lower pitched and longer calls as more threatening by looking towards the source of the call sooner and for longer than others.
Whilst males are silent for most of the year, they call intensely for the brief period of the mating season. Larger and more dominant fallow bucks tend to make lower frequency calls. As animals become tired from competing for mates, their calls become shorter and higher frequency. The researchers found that the bucks are able to hear subtle differences and make judgements about the level of competition they might face from the caller.
Commenting, QMUL’s Dr Ben Pitcher, said: “Deep calls help to beat other males in the quest for mates, and over generations competition between males for mates has driven the evolution of deeper, lower pitched and longer calls. Just like humans, fallow bucks can listen to the sounds of a rival’s voice and assess if they are dominant or pose a threat.”
Adding his thoughts, Dr Alan McElligott, also of QMUL and co-author of the study, said: “Bucks get into a lot of confrontations during the annual rut and being able to tell from a distance how big and how fresh another buck is might help them avoid being on the end of an unnecessary beating.”
The full results are published in the journal BMC Evolutionary Biology.
