Primates and Predator Interactions

[TheHyenid76]

Responses of Chimpanzees to a Python

Introduction

Chimpanzees in captivity have been known to show fear response to snakes, and wild chimpanzees in Gombe, Tanzania, showed not only fear and avoidance responses (e.g., leaping back, moving away) but also aggressive behavior (e.g., hitting the snake, chasing and stamping on the ground, shaking saplings) toward live snakes (Causus rhombeatus, Philothamnus spp, etc.). Wild chimpanzees have also been known to express a “waa” bark and a “huu” (“hoo”) call, when they saw snakes. However, few observations of the reactions of chimpanzees to snakes have been made in the wild.

African pythons (Python sabae) have been thought to be among the potential predators of juvenile and infant chimpanzees4. Only one case involving the reactions of wild chimpanzees to a half-dead python has been reported under experimental conditions in Gombe2. However, no reports on encounters between wild chimpanzees and wild pythons have been published. In this study, I will report on the response of wild chimpanzees to a live python.

Figure 1. A python sticking out of the bush.
Figure 2. PF watched the python intently from the woody vine.
Figure 3. PM grimaced tracking the python.
Figure 4. PM (left), AL, RB carrying her infant ventrally, and RC (right) tracked the python.

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

Discussion

Chimpanzees in Gombe showed fear and avoidance responses (rushing away, climbing trees) accompanied by loud “wraa” and soft “huu” calls when they detected a nearly dead python placed within the observation area. Chimpanzees in Mahale also expressed “wraa” and “huu” calls, but after watching the python, only “huu” calls, which express puzzlement, surprise, or slight anxiety directed toward such phenomena as small snakes, rustling noises made by unidentified creatures, and so on were heard. Chimpanzees in Mahale also showed fear and avoidance responses (leaping back, climbing on vines, grimacing) to a python, but they were thought to be more interested in the python because they spent more time waiting, watching, and tracking it. Even a mother with her infant held ventrally and a juvenile followed the python despite its status as a potential predator of juvenile and infant chimpanzees.

Many species of primates face a risk of predation from snakes. It has been hypothesized that the need to avoid snakes shaped the evolution of the primate visual system. This hypothesis has been supported by experiments on Japanese monkeys (Macaca fuscata) reared with no experience with snakes who rapidly detected a picture of a snake. Wild chimpanzees have been shown to detect and avoid pythons, but they also expressed interest in and approached these creatures. Although many researchers have studied chimpanzees in Mahale over the course 40 years, this is the only case of an encounter between chimpanzees and a python that has been reported. Because the chimpanzees of Mahale may not have been exactly sure about the nature of a python due to their lack of experience with this species, they may have been attracted to and puzzled by it.

Responses of Chimpanzees to a Python Reply