Monitoring coyote population dynamics by genotyping faeces

Abstract

Reliable population estimates are necessary for effective conservation and management, and faecal genotyping has been used successfully to estimate the population size of several elusive mammalian species. Information such as changes in population size over time and survival rates, however, are often more useful for conservation biology than single population estimates. We evaluated the use of faecal genotyping as a tool for monitoring long-term population dynamics, using coyotes (Canis latrans) in the Alaska Range as a case study. We obtained 544 genotypes from 56 coyotes over 3 years (2000-2002). Tissue samples from all 15 radio-collared coyotes in our study area had > or = 1 matching faecal genotypes. We used flexible maximum-likelihood models to study coyote population dynamics, and we tested model performance against radio telemetry data. The staple prey of coyotes, snowshoe hares (Lepus americanus), dramatically declined during this study, and the coyote population declined nearly two-fold with a 1(1/2)-year time lag. Survival rates declined the year after hares crashed but recovered the following year. We conclude that long-term monitoring of elusive species using faecal genotyping is feasible and can provide data that are useful for wildlife conservation and management. We highlight some drawbacks of standard open-population models, such as low precision and the requirement of discrete sampling intervals, and we suggest that the development of open models designed for continuously collected data would enhance the utility of faecal genotyping as a monitoring tool.

Genetic monitoring as a promising tool for conservation and management

“…Traditionally, survival has been difficult to estimate, much less monitor, for rare and elusive species. The ability to use molecular data to track known individuals can either replace or augment traditional efforts to monitor survival [16]. For instance, naturally shed feathers of Eastern imperial eagles Aquila heliaca have been used in a microsatellite analysis to identify individuals, monitor population turnover and estimate annual survivorship over a four-year period [17].…”

Amplifiability of mitochondrial, microsatellite and amelogenin DNA loci from fecal samples of red brocket deer Mazama americana (Cetartiodactyla, Cervidae)

“…Oliveira and J.M.B. Duarte samples to study wildlife populations involved sample collections conducted in cold climate regions (-20° to 10°C) (e.g., Frantz et al, 2003;Creel et al, 2003;Prugh et al, 2005) and/or the animal was observed at a distance until defecation, when the samples were collected in a fresh state, or the samples were collected from nests (e.g., Morin et al, 2001;Nsubuga et al, 2004). Weather and sample collection conditions such as those described are not realistic for many Neotropical species, such as deer of the genus Mazama.…”

Identification of pumas (Puma concolor (Linnaeus, 1771)) through faeces: a comparison between morphological and molecular methods

“…Often, the presence of these animals may be confirmed through the identification of their faeces, avoiding the elevated costs of capture and its possible damages (Wayne and Morin, 2004). Faecal analysis allows the monitoring of populations, their movements (Kohn and Wayne, 1997;Taberlet et al, 1997;Prugh et al, 2005), and provides diet-related information (Farrel et al, 2000).…”

“…In the last decade, a large number of population studies have been based on faecal DNA analysis (Taberlet et al, 1997;Wasser et al, 1997;Palomares et al, 2002;Riddle et al, 2003;Deagle et al, 2005;Prugh et al, 2005).…”