Dynamics of direct inter-pack encounters in endangered African wild dogs

作者:Jordan Neil R; Buse Christopher; Wilson Alan M; Golabek Krystyna A; Apps Peter J; Lowe John C; Van der Weyde Leanne K; McNutt J Weldon
来源:Behavioral Ecology and Sociobiology, 2017, 71(8): UNSP 115.
DOI:10.1007/s00265-017-2338-9

摘要

Aggressive encounters may have important life history consequences due to the potential for injury and death, disease transmission, dispersal opportunities or exclusion from key areas of the home range. Despite this, little is known of their detailed dynamics, mainly due to the difficulties of directly observing encounters in detail. Here, we describe detailed spatial dynamics of inter-pack encounters in African wild dogs (Lycaon pictus), using data from custom-built high-resolution GPS collars in 11 freeranging packs. On average, each pack encountered another pack approximately every 7 weeks and met each neighbour twice each year. Surprisingly, intruders were more likely to win encounters (winning 78.6% of encounters by remaining closer to the site in the short term). However, intruders did tend to move farther than residents toward their own range core in the short-term (1 h) postencounter, and if this were used to indicate losing an encounter, then the majority (73.3%) of encounters were won by residents. Surprisingly, relative pack size had little effect on encounter outcome, and injuries were rare (< 15% of encounters). These results highlight the difficulty of remotely scoring encounters involving mobile participants away from static defendable food resources. Although inter-pack range overlap was reduced following an encounter, encounter outcome did not seem to drive this, as both packs shifted their ranges post-encounter. Our results indicate that inter-pack encounters may be lower risk than previously suggested and do not appear to influence long-term movement and ranging. Significance statement Direct aggressive encounters between competitors are an important and potentially dangerous aspect of territoriality. In spite of this, detailed data on movements in response to encounters are lacking, especially for large mammals. Collecting observational data on competitors leaving an encounter site in different directions is logistically challenging, and radiocollar technology has previously been ineffective in this regard due to low temporal resolution. We overcame these issues by using custom-built high-resolution GPS collars, showing that intruding African wild dog packs were more likely to win inter-pack encounters (residents initially moved further away from the encounter). Inter-pack encounters appeared to have only short-term impacts on movement, with their outcome having no discernible impact on the long-term ranging patterns of African wild dog packs.

  • 出版日期2017-8