Population dynamics, intervention and survival in African wild dogs (Lycaon pictus).
The demography of Serengeti wild dog study packs and their extinction in 1991 was documented by Burrows et al. (1994). One explanation for pack loss compatible with demographic evidence was viral disease induced by stress caused by intervention (vaccination, immobilization and radio-collaring). Several studies claim to reject this hypothesis. However, cortisol levels measured in immobilized Lycaon, whose pathogen exposure is unknown, do not demonstrate that interventions in the Serengeti were benign. The analysis of survivorship in Lycaon in other ecosystems minimized the chance of demonstrating any effect of intervention and failed to consider vaccinations as intervention. There is now evidence that intervention significantly decreased survivorship of Masai Mara Lycaon. Further simulations of the likelihood of population extinction in Serengeti Lycaon, evidence of limited population variability and a small scaling factor in Serengeti Lycaon strengthen Burrows et al.'s conclusion that the extinction was unlikely to be due to chance alone. Although some studies claim that Lycaon conservation is doomed without intervention, to date vaccinations, blood sampling and radio-telemetry have contributed little to Lycaon conservation. All studies fail to disprove the Burrows hypothesis or provide convincing alternatives.
Department of Continuing and Adult Education, University of Exeter, Cotley, Streatham Rise, UK.
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D000818:Animals; D000835:Animals, Wild / Q000502:physiology* / Q000523:psychology; D004285:Dogs; D006234:Handling, Psychological; D011157:Population Dynamics; D013315:Stress, Psychological