Dr. Sharon Gursky
Assisant Professor of Anthropology, Texas A&M University
Title:
Predator Mobbing in the Spectral Tarsier
Abstract:
Numerous species are known for their tendency to approach and confront their
predators as a group. This behavior is known as mobbing. This paper will explore
individual differences (sex and age) in the mobbing behavior of the spectral
tarsier toward live and model snakes. During this research, 11 natural mobbing
events and 31 artificially induced mobbing events were observed. The mean number
of individuals at a mobbing was 5.7. The duration of mobbing events was strongly
correlated with the number of assembled mobbers. Adults were more likely than
other age classes to participate in mobbings.
Males were more likely than females to participate in mobbings.
Mobbing groups often contained more than one adult male despite the fact that no
spectral tarsier group contains more than one adult male. No difference in body
size between extra group males and resident males was observed refuting the
Attract the Mightier hypothesis. The number of mobbers did not affect whether
the tarsier
or the snake retreated first countering the Move-On hypothesis. The
Perception Advertisement hypothesis was tentatively supported in that the live
snakes were rarely seen in the area following mobbing calls in comparison to
when the tarsiers either ignore the snake or alarm call.