Landscape effects on the contemporary genetic structure of Ruffed Grouse (Bonasa umbellus) populations

Abstract

The amount of dispersal that occurs among populations can be limited by landscape heterogeneity, which is often due to both natural processes and anthropogenic activity leading to habitat loss or fragmentation. Understanding how populations are structured and mapping existing dispersal corridors among populations is imperative to both determining contemporary forces mediating population connectivity, and informing proper management of species with fragmented populations. Furthermore, the contemporary processes mediating gene flow across heterogeneous landscapes on a large scale are understudied, particularly with respect to widespread species. This study focuses on a widespread game bird, the Ruffed Grouse (Bonasa umbellus), for which we analyzed samples from the western extent of the range. Using three types of genetic markers, we uncovered multiple factors acting in concert that are responsible for mediating contemporary population connectivity in this species. Multiple genetically distinct groups were detected; microsatellite markers revealed six groups, and a mitochondrial marker revealed four. Many populations of Ruffed Grouse are genetically isolated, likely by macrogeographic barriers. Furthermore, the addition of landscape genetic methods not only corroborated genetic structure results, but also uncovered compelling evidence that dispersal resistance created by areas of unsuitable habitat is the most important factor mediating population connectivity among the sampled populations. This research has important implications for both our study species and other inhabitants of the early successional forest habitat preferred by Ruffed Grouse. Moreover, it adds to a growing body of evidence that isolation by resistance is more prevalent in shaping population structure of widespread species than previously thought.

Mitochondrial DNA variation of the ruffed grouse (Bonasa umbellus)

“…Although not completely congruent with currently designated subspecies of ruffed grouse, observed patterns of genetic variation confirm that ruffed grouse show evidence of population subdivision, and some of this variation coincides with portions of the range of recognized subspecies. For instance, a recent study [10] based on microsatellite and mtDNA markers revealed high levels of population differentiation of populations from Alaska and Washington, with evidence of subdivision for populations from western Canada. Our data indicate that populations containing individuals from Washington, Idaho, and Montana (Group 1) represent one of the most distinct and divergent groups of ruffed grouse.…”

“…Although previous studies clearly document morphological and ecological differences across the ruffed grouse’s range, morphology-based taxonomy is not always congruent with geographic patterns of genetic variation [8], thus making it difficult to identify units of conservation [9]. To the best of our knowledge, the only genetic study of ruffed grouse assesses the landscape genetics of populations from the extreme western range of the species [10].…”

Courtship display speed varies daily and with body size in the Ruffed Grouse (Bonasa umbellus)

“…This site is along the eastern slope of the Rocky Mountains, but the lower elevations contains a comparable forest type to Buck Lake with trembling aspen and white birch ( Betula papyrifera ) stands mixed with assorted conifer species, shrubs, and a few small muskeg patches. We used this second site in April‐May 2016 to sample individuals for a population genetics study (Jensen, O'Neil, Iwaniuk, & Burg, ).…”

“…Once caught, each male bird was placed into a dark‐colored pillowcase, weighed with a spring scale (±5 g) and linear measurements taken of the tarsus with plastic calipers (±0.5 mm) and the wing chord with a wing rule (±1 mm). Finally, blood samples were taken using brachial venipuncture for a population genetics study (Jensen et al, ), after which the grouse was released. All procedures adhered to the Canada Council for Animal Care regulations were approved by the University of Lethbridge Animal Welfare Committee and collected under research permits issued by Alberta Environment and Parks.…”

Climate change models predict decreases in the range of a microendemic freshwater fish in Honduras

“…These SDMs can be a robust source of information in the absence of empirical ecological data 5 – 7 . In addition to contemporary distributions 8 , 9 , models can be projected onto paleo- and future landscapes to test hypotheses related to temporal range shifts based on changing conditions (e.g. glaciation cycles, future climate predictions 10 , 11 ).…”