Species‐specific responses to landscape features shaped genomic structure within Alaska galliformes

Abstract

Aim: Connectivity is vital to the resiliency of populations to environmental change and stochastic events, especially for cold-adapted species as Arctic and alpine tundra habitats retract as the climate warms. We examined the influence of past and current landscapes on genomic connectivity in cold-adapted galliformes as a critical first step to assess the vulnerability of Alaska ptarmigan and grouse to environmental change.We hypothesize that the mosaic of physical features and habitat within Alaska promoted the formation of genetic structure across species.Location: Alaska, United States of America.Taxa: Ptarmigan and Grouse (Galliformes: Tetraoninae). Methods:We collected double digest restriction-site-associated DNA sequence data from six ptarmigan and grouse species (N = 13-145/species) sampled across multiple ecosystems up to ~10 degrees of latitude. Spatial genomic structure was analysed using methods that reflect different temporal scales: (1) principal components analysis to identify major trends in the distribution of genomic variation; (2) maximum likelihood clustering analyses to test for the presence of multiple genomic groupings; (3) shared co-ancestry analyses to assess contemporary relationships and (4) effective migration surfaces to identify regions that deviate from a null model of isolation by distance.Results: Levels of genomic structure varied across species (Φ ST =0.009-0.042). Three general patterns of structure emerged: (1) east-west partition located near the Yukon-Tanana uplands; (2) north-south split coinciding with the Alaska Range and (3) northern group near the Brooks Range. Species-specific patterns were observed; not all landscape features were barriers to gene flow for all ptarmigan and grouse and temporal contrasts were detected at the Brooks Range.Main conclusions: Within Alaska galliformes, patterns of genomic structure coincide with physiographic features and highlight the importance of physical and ecological barriers in shaping how genomic diversity is arrayed across the landscape. Lack of concordance in spatial patterns indicates that species behaviour and habitat affinities play key roles in driving the contrasting patterns of genomic structure.

Diversity, distribution, and methodological considerations of haemosporidian infections among Galliformes in Alaska

“…Blood smears were collected but were of insufficient quality for thorough analysis for this study. Samples were collected either during fall or winter from shot hunter-harvested birds, or spring and summer as part of a large galliform population genetic assessment project ( Sonsthagen et al, 2022 ) with date, age, and location point data collected for each individual (see Sonsthagen and Wilson, 2020 for detailed sample information). All hunter-harvested samples were collected following local and state hunting regulations and all other samples hunter-harvested outside of those regulations were collected under scientific collecting permit though Alaska, Department of Fish and Game (Scientific Permits 15–108, 16–109 and 17–109) and U.S. Geological Survey Alaska Science Center ACUC (assurance plan code 2015–03).…”

“…Most of the individuals (N = 317/419) were sampled in the field: muscle samples were taken within 3 h and blood samples were taken within 30 min, with the remaining 102 samples processed off-site. Muscle samples taken in the field were initially stored in liquid nitrogen and then transferred to a −80C freezer until extraction, and tissues processed in the lab were stored in −80C freezer ( Sonsthagen et al, 2022 ). Blood was extracted before dissection, stored in blood preservation buffer ( Longmire et al, 1988 ) and collected from 227 individuals: willow ptarmigan (N = 106), rock ptarmigan (N = 99), spruce grouse (N = 15), and ruffed grouse (N = 7).…”