Conservation in the southern edge of Tetrao urogallus distribution: Gene flow despite fragmentation in the stronghold of the Cantabrian capercaillie

Abstract

The Cantabrian capercaillie (Tetrao urogallus cantabricus) is an endangered subspecies of the Western capercaillie, endemic of northern Spain, inhabiting the south-western limit of the species range. Assessing genetic variability and the factors that determine it is crucial in order to develop an effective conservation strategy. In this work, non-invasive samples were collected in some of the best preserved areas inhabited by Cantabrian capercaillie. Nine microsatellite loci and a sexspecific marker were analysed. We included five zones, separated by valleys with different levels of habitat modifications. No evidence of genetic clustering was found which suggests that fragmentation and development in the area do not act as barriers to gene flow. Nonetheless, significant differences among sampling zones were encountered in terms of their allelic frequencies (global F ST = 0.035, p = 0.001). Pairwise F ST comparisons showed differences between all sampling zones included, except between the two ones located in the South (Degaña and Alto Sil). These findings, along with the results of individual based genetic differences, indicate that gene flow among sampling zones might be at least slightly compromised, except between the two zones located in the South. Despite this, the sampling zones seem to exchange migrants at a rate that prevents genetic differentiation to the point of creating clusters. Our results show that the capercaillies in the study area constitute a single interbreeding group, which is an important piece of information that provides support to better understand the dynamics of this endangered subspecies.

Genetic structure and diversity of the capercaillie (Tetrao urogallus) population in Belarus in the context of de-lineation of two subspecies: major and pleskei

“…Strzała et al (2015) provides the following genetic diversity estimates for the capercaillie population of the Capercaillie Breeding Centre in Wisła Forest District: H e = 0.755, Ho = 0.772, N a = 6.3, as well as similar estimations for the capercaillie population of the Bory Dolnośląskie Forest: H e = 0.675, H o = 0.863, N a = 5.3 [Strzała et al 2015]. In general, the genetic diversity estimates for the studied capercaillie subpopulations in Belarus are similar to or slightly higher than the estimates for the Pol ish populations [Strzała et al 2015;Rutkowski et al 2017b], the boreal forests area [Segelbacher et al 2003b], or Southern Europe (the Balkans) [Klinga et al 2020], and higher than the estimates for the populations of Central (Germany, Austria, Italy, and Slovenia) [Segelbacher & Storch 2002;Segel bacher et al 2008] and Western (Cantabrian, Pyrenees, and Vosges mountains) Europe [Rodríguez Muñoz et al 2007;MoránLuis et al 2014;Fameli et al 2017;Cayuela et al 2021]. The obtained inbreeding coefficient estimates for the Belarusian subpopulations of capercaillie match those of the Polish populations (in both cases, the values are not statistically significant) [Strzała et al 2015;Rut kowski et al 2017b], but this estimate does not show high values across the capercaillie range in general [Segelbacher et al 2003a;RodríguezMuñoz et al 2007], with the exception of several popula tions that experienced known dramatic population declines in the past [Cayuela et al 2021].…”

“…A low level of errors associated with the quality of reading of fragment analysis data as well as with the amplification are noted for the used microsatellite loci [Strzała et al 2015;Rutkowski et al 2017b;Fameli et al 2017]. Microsatellite loci BG10 and BG12 were not used in the current work on the genotyping of capercaillie population due to the linkage with sex chromosomes [Strzała et al 2015].…”

“…The existing data on genetic diversity and structure of capercaillie populations indicate that the population of boreal forests area is in a generally good state [Segelbacher et al 2003]. While studies of populations from Central [Segelbacher & Storch 2002;Segelbacher et al 2003a;Segelbacher et al 2003b;Segelbacher et al 2008;Rutkowski et al 2017b], Western [Fameli et al 2017], and Southern Europe [Klinga et al 2015;Klinga et al 2020] show how necessary is the timely consideration of genetic characteristics for a conservation strategy under the conditions of continuously increasing anthropogenic pressure expressed in continuous transformation of the species' natural habitat. The consequential fragmentation of habitats presents a significant source of genetic diversity loss due to disruption of gene flow, decline of population groups, and shrinkage the population of leks [Cayuela et al 2021].…”

Fine‐scale genetic structure in an eastern Alpine black grouse Tetrao tetrix metapopulation

“…This was also suggested by Corrales and Höglund (2012) for a continuously distributed black grouse population in northern Sweden and for Alpine capercaillie (Segelbacher and Storch 2002). For the Cantabrian capercaillie, Fameli et al (2017) did not find distinct genetic structuring despite of anthropogenic fragmentation of the area as well, suggesting maintenance of connectivity. The spread of genes obviously exceeds the assumed dispersal capabilities of black grouse, spanning from 5 to 29 km for females, which is the farther dispersing sex in black grouse, and reaching up to 8.5 km for males Ellison 2002, Warren andBaines 2002).…”

Current trends in the application of non-invasive genetic sampling to study Neotropical birds: Uses, goals, and conservation potential

“…13,19 For example, studies based on NGS of the capercaillie ( Tetrao urogallus ), an Eurasian galliform, have pioneered the use of feces and feathers as sources of genetic material. 17,20–24…”