UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory
Deer Abundance and Sex Ratio

Contact

Ben Sacks, Director
Mammalian Ecology and Conservation Unit, Veterinary Genetics Laboratory
Contact by Email is preferred.

Background

Estimates or indexes of abundance and sex ratio are essential to ungulate management and monitoring programs, yet can be difficult to obtain through traditional approaches in certain circumstances (e.g., forested habitats that impede visibility for aerial surveys).  Therefore, use of noninvasive capture-mark-recapture (CMR) approaches that utilize individual genetic “fingerprints” gathered from fecal pellets have been gaining popularity as an alternative.  This approach has both advantages and disadvantages to traditional approaches.  For example, fecal CMR approaches have potential to provide precise, unbiased estimates of abundance, density, and (if sex markers are included in genotyping) sex ratio that are comparable across study sites and regions, regardless of visibility, enabling more reliable data with which to monitor population trends, especially when conducted in a regional framework.  The main disadvantages are costs associated with intensive field collection activities and laboratory analysis. Thus, fecal CMR approaches are likely to be most useful when strategically integrated with traditional monitoring approaches.

Our Services

We provide a range of services based on fecal pellets from deer or other ruminants provided to us (see below for sample preservation protocols), including individual genotyping with 10 microsatellite markers and an SRY marker to determine sex as well as species-typing based on mitochondrial sequencing (i.e., only necessary when species or origin is ambiguous).  Analysis of genotypic data to produce abundance estimates also can be arranged.

Pilot Studies

Genotyping success can vary substantially based on the study area and time of year, due to any number of factors, such as climate, precipitation, herbivore diet, etc.  Therefore, we recommend conducting pilot studies using ~100 pellet samples prior to finalizing plans for a project, as success can range from 30 to 80%, which makes a significant difference with respect to numbers of samples required to meet study objectives.

 
Veterinary Genetics Laboratory, Tel 530-752-2211, Email VGL