Demographic Status and Genetic Tagging of Endangered Capercaillie in NW Spain

Abstract

Counting rare and elusive animals and evaluating their demographic status, are fundamental yet challenging aspects of population ecology and conservation biology. We set out to estimate population size (Nc), genetic effective population size (Ne gen), sex ratio, and movements based on genetic tagging for the threatened Cantabrian capercaillie. We used 9 microsatellite loci to genotype 134 droppings collected at 34 display areas during the breeding season. Using genetic capture-mark-recapture, we estimated 93 individuals (Nc, 95% CI: 70–116) in an area of about 500 km2, with sex ratio biased towards males (1∶1.6). Estimated Ne gen (35.5) was 38% of Nc, notably higher than the published average in wild populations. This capercaillie population is small and well within concern in terms of population viability. By genetic tagging, we detected mostly short movements; just a few males were recaptured between contiguous display areas. Non-invasive surveys of endangered populations have a great potential, yet adequate sample size and location are key to obtain reliable information on conservation status.

Tetrao urogallus: BirdLife International

“…The genetic diversity of the population from the Tatra National Park, estimated based on samples from 2016, was slightly lower than the values reported previously for -2014(Rutkowski et al 2015, 2017, either in terms of the number of alleles or the level of heterozygosity. This could indicate that genetic diversity has been decreasing in the investigated population.…”

“…These indicate that our genotyping procedure performs well in estimating the abundance of the capercaillie in the investigated population. Indeed, genetic analysis of non-invasively collected samples provided insight into the demography and ecology of different caprecaillie populations (Jacob et al 2010, Morán-Luis et al 2014, Mollet et al 2015.…”

Importance and effectiveness of correction methods for spatial sampling bias in species with sex‐specific habitat preference

“…However, the number of observations available for the systematic design was very low (29), thus more data are needed to confirm this pattern. Nevertheless, the ratio of males observed with systematic sampling (0.59) was slightly lower than the one reported by previous studies (0.63 and 0.625) that used subjective sampling (Mollet et al, ; Morán‐Luis et al, ). Only the targeted correction methods in the case of subjective sampling had the expected effect on the estimated sex ratio, whereas the other cases showed lower value than observed from the number of observations.…”

“…Indeed, assuming that the true sex ratio is 0.5, in that study the estimated sex ratio was biased toward males, reflecting the low proportion of female signs found by this sampling protocol. A second study found the same results (Morán‐Luis et al, ) for the Cantabrian Capercaillie ( Tetrao urogallus cantabricus ) subspecies.…”

The edge also matters: human threats in a rare Mediterranean habitat for Cantabrian Capercaillie

“…We studied the Cantabrian Capercaillie Tetrao urogallus cantabricus , a subspecies of the Western Capercaillie T. urogallus, inhabiting montane forests of the Cantabrian range (north-west Spain). The population has been declining dramatically in the last decades and is currently restricted to an area of less than 1,700 km 2 with a very low population size, of great concern in terms of population viability (Storch et al 2006, Moran-Luis et al 2014). Hence, further habitat destruction or landscape fragmentation will likely be very detrimental to this population (Quevedo et al 2006a,b).…”