Assessment of drivers of spatial genetic variation of a ground‐dwelling bird species and its implications for conservation

Abstract

In modern wildlife ecology, spatial population genetic methods are becoming increasingly applied. Especially for animal species in fragmented landscapes, preservation of gene flow becomes a high priority target in order to restore genetic diversity and prevent local extinction. Within Central Europe, the Alps represent the core distribution area of the black grouse, Lyrurus tetrix. At its easternmost Alpine range, events of subpopulation extinction have already been documented in the past decades. Molecular data combined with spatial analyses can help to assess landscape effects on genetic variation and therefore can be informative for conservation management. Here, we addressed whether the genetic pattern of the easternmost Alpine black grouse metapopulation system is driven by isolation by distance or isolation by resistance. Correlative ecological niche modeling was used to assess geographic distances and landscape resistances. We then applied regression‐based approaches combined with population genetic analyses based on microsatellite data to disentangle effects of isolation by distance and isolation by resistance among individuals and subpopulations. Although population genetic analyses revealed overall low levels of genetic differentiation, the ecological niche modeling showed subpopulations to be clearly delimited by habitat structures. Spatial genetic variation could be attributed to effects of isolation by distance among individuals and isolation by resistance among subpopulations, yet unknown effects might factor in. The easternmost subpopulation was the most differentiated, and at the same time, immigration was not detected; hence, its long‐term survival might be threatened. Our study provides valuable insights into the spatial genetic variation of this small‐scale metapopulation system of Alpine black grouse.

Landscape features influencing gene flow and connectivity of an endangered passerine

“…This pattern agrees with the genetic structure observed in Spain, where some genetic clusters are not entirely isolated . Similar patterns have been identified for other bird species mainly because of their high dispersal capacities (Kleinhans & Willows-Munro, 2019;Koopman et al, 2007;Kunz et al, 2022).…”

“…This pattern agrees with the genetic structure observed in Spain, where some genetic clusters are not entirely isolated (Méndez, Tella, & Godoy, 2011 ). Similar patterns have been identified for other bird species mainly because of their high dispersal capacities (Kleinhans & Willows‐Munro, 2019 ; Koopman et al., 2007 ; Kunz et al., 2022 ). To directly evaluate the landscape influence on the stepping‐stone connectivity, future studies should consider a sampling design that specifically accounts for the habitat features of patches potentially serving as stepping stones (Duforet‐Frebourg & Slatkin, 2016 ).…”

An evaluation of isolation by distance and isolation by resistance on genetic structure of the Persian squirrel (Sciurus anomalus) in the Zagros forests of Iran

“…For example, Seaborn et al ( 2019 ) found that although individual‐based sampling was helpful for increasing sampling extent and density, it may lack power for model comparisons compared with population‐based sampling. Kunz et al ( 2022 ) also found differing support for IBD versus IBR among individuals compared to among subpopulations. In our case, given the lack of clear subpopulations or distinct sampling areas within our sample, an individual‐based approach was both necessary and justified.…”

“…The IBR framework can improve understanding of how a broad range of landscape features and characteristics simultaneously influence gene flow and movement, ultimately allowing researchers to predict both ecological and evolutionary consequences of landscape change. By investigating the roles of isolation by distance (IBD) and isolation by resistance (IBR) in determining genetic structure, we can gain a more complete understanding of the effects of spatial distance and habitat heterogeneity on species distribution, abundance, and movement (Kunz et al, 2022 ; McRae, 2006 ).…”

Local ecological divergence of two closely related stag beetles based on genetic, morphological, and environmental analyses

“…Meanwhile, dispersal ability could influence range limits and gene flow among populations, which may be associated with niche differentiation. In addition, previous studies showed that morphological adaptation to local ecology can also have resulted from phenotypic plasticity or from genetic differences among populations (Borokini et al, 2021 ; Ghalambor et al, 2007 ; Kunz et al, 2022 ; Price et al, 2003 ; Schmid & Guillaume, 2017 ). Although phenotypic plasticity has been documented in response to variations in multiple environmental variables (Chevin & Lande, 2015 ; Gratani, 2014 ; Lande, 2009 ; Wang et al, 2021 ), we found morphological distance was not correlated with environmental distance after controlling for geographic distance (Table 6 ).…”