Estimating population size using single‐nucleotide polymorphism‐based pedigree data

Abstract

Reliable population estimates are an important aspect of sustainable wildlife management and conservation but can be difficult to obtain for rare and elusive species. Here, we test a new census method based on pedigree reconstruction recently developed by Creel and Rosenblatt (2013). Using a panel of 96 single‐nucleotide polymorphisms (SNPs), we genotyped fecal samples from two Swedish brown bear populations for pedigree reconstruction. Based on 433 genotypes from central Sweden (CS) and 265 from northern Sweden (NS), the population estimates (N = 630 for CS, N = 408 for NS) fell within the 95% CI of the official estimates. The precision and accuracy improved with increasing sampling intensity. Like genetic capture–mark–recapture methods, this method can be applied to data from a single sampling session. Pedigree reconstruction combined with noninvasive genetic sampling may thus augment population estimates, particularly for rare and elusive species for which sampling may be challenging.

Spatiotemporal relationship between adult census size and genetic population size across a wide population size gradient

“…; Spitzer et al . ). As a result, for practical reasons, there is substantial interest in determining whether especially the demographic ( N ) and genetic ( N b , N e ) parameters can be used to infer the other (Antao et al .…”

“…; Spitzer et al . ), identifying threatened or endangered populations (Vié et al . ) and forecasting changes in population dynamics (Grueber et al .…”

“…The estimation of adult census population size (N), effective number of breeders (N b ) and effective population size (N e ) are important for designing effective conservation strategies (Katzner et al 2011;Spitzer et al 2016), identifying threatened or endangered populations (Vi e et al 2008) and forecasting changes in population dynamics (Grueber et al 2012;Fordham et al 2014). While demographic events contribute to changes in N (recruitment failure, increased mortality, etc.…”

Genetic and genomic monitoring with minimally invasive sampling methods

“…This approach increased success rates by 20%-30% and decreased costs per sample by 40% compared to traditional capillary electrophoresis genotyping of microsatellite loci. Also, SNP loci have been identified for brown bears and successfully genotyped for faecal samples using the Fluidigm platform (Norman & Spong, 2015;Spitzer, Norman, Schneider, & Spong, 2016). These advancements using genomic methods provide much promise for the continued noninvasive genetic monitoring of brown bears across their range.…”

Can estimates of genetic effective population size contribute to fisheries stock assessments?

“…Genetic data can also be used to determine the extent of allele-sharing (Skaug, 2001) among individuals to estimate absolute abundance using an experimental design that is analogous to CMR. The close-kin (Bravington et al, 2016) and Creel-Rosenblatt pedigree reconstruction (Spitzer et al, 2016) methods are two examples of this approach.…”