Reduced Representation and Whole-Genome Sequencing Approaches Highlight Beluga Whale Populations Associated to Eastern Canada Summer Aggregations.

Effective conservation strategies inherently depend on preserving populations, which in turn requires accurate tools for their detection. Beluga whales () inhabit the circumpolar Arctic and form discrete summer aggregations. Previous genetic studies using mitochondrial and microsatellite loci have delineated distinct populations associated to summer aggregations but the extent of dispersal and interbreeding among these populations remains largely unknown.

Assessing the Impacts of Adaptation to Native-Range Habitats and Contemporary Founder Effects on Genetic Diversity in an Invasive Fish.

Species invading non-native habitats can cause irreversible environmental damage and economic harm. Yet, how introduced species become widespread invaders remains poorly understood. Adaptation within native-range habitats and rapid adaptation to new environments may both influence invasion success.

Individual timing consistency across long-distance songbird migrations.

Migration timing in long-distance migratory birds plays an essential role in individual survival and fitness and is thought to be driven by circannual routines cued by photoperiod with some plasticity to environmental conditions. We examined the individual order of migration timing in purple martins (), a neotropical migratory songbird that travels between breeding sites throughout eastern North America and nonbreeding sites in Brazil. Migration timing data were collected for 295 different individual purple martins over 9 years using light-level geolocators deployed at breeding sites across the range.

Comparison of metabolic rate between two genetically distinct populations of lake sturgeon.

Environmental temperatures differ across latitudes in the temperate zone, with relatively lower summer and fall temperatures in the north leading to a shorter growing season prior to winter. As an adaptive response, during early life stages, fish in northern latitudes may grow faster than their conspecifics in southern latitudes, which potentially manifests as different allometric relationships between body mass and metabolic rate. In the present study, we examined if population or year class had an effect on the variation of metabolic rate and metabolic scaling of age-0 lake sturgeon () by examining these traits in both a northern (Nelson River) and a southern (Winnipeg River) population.

Feast to famine: Sympatric predators respond differently to seasonal prey scarcity on the low Arctic tundra.

Resource fluctuation is a major driver of animal movement, influencing strategic choices such as residency vs nomadism, or social dynamics. The Arctic tundra is characterized by strong seasonality: Resources are abundant during the short summers but scarce in winters. Therefore, expansion of boreal-forest species onto the tundra raises questions on how they cope with winter-resource scarcity.

Genetic diversity and structure of a recent fish invasion: Tench () in eastern North America.

Introduced and geographically expanding populations experience similar eco-evolutionary challenges, including founder events, genetic bottlenecks, and novel environments. Theory predicts that reduced genetic diversity resulting from such phenomena limits the success of introduced populations. Using 1900 SNPs obtained from restriction-site-associated DNA sequencing, we evaluated hypotheses related to the invasion history and connectivity of an invasive population of Tench (), a Eurasian freshwater fish that has been expanding geographically in eastern North America for three decades.

A simple, low-cost method to age mammals? An alternative to cementum annuli analysis.

One of the most common and ubiquitous methods to age mammals is by counting the cementum annuli in molars, premolars, incisors, or canines. Despite the ubiquity and perceived simplicity of the method, cementum annuli analysis can be time-consuming, expensive, inaccurate, and imprecise, and require specialized equipment. Using beavers () as a test species, we developed a straightforward method to age mammals that requires little specialized equipment.

Intraspecific variation in male mating strategies in an African ground squirrel ().

Male mating strategies respond to female availability such that variation in resources that affect spatial distribution can also alter cost-benefit tradeoffs within a population. In arid-adapted species, rainfall alters reproduction, behavior, morphology, and population density such that populations differing in resource availability may also differ in successful reproductive strategies. Here, we compare two populations of Cape ground squirrels (), a sub-Saharan species with year-round breeding and intense mating competition.

A chromosomal inversion may facilitate adaptation despite periodic gene flow in a freshwater fish.

Differences in genomic architecture between populations, such as chromosomal inversions, may play an important role in facilitating adaptation despite opportunities for gene flow. One system where chromosomal inversions may be important for eco-evolutionary dynamics is in freshwater fishes, which often live in heterogenous environments characterized by varying levels of connectivity and varying opportunities for gene flow. In the present study, reduced representation sequencing was used to study possible adaptation in = 345 walleye () from three North American waterbodies: Cedar Bluff Reservoir (Kansas, USA), Lake Manitoba (Manitoba, Canada), and Lake Winnipeg (Manitoba, Canada).

Using microcontrollers and sensors to build an inexpensive CO control system for growth chambers.

Premise: A CO control system is important for investigating how elevated CO affects plant growth. Our automatic CO monitoring and control system offers an inexpensive and flexible way to make CO-enriched environments.

Method And Results: Using microcontrollers paired with non-dispersive infrared CO sensors, relays, and valves, we developed a low-cost system for monitoring and controlling CO levels in growth chambers.

Divergent transcriptomic signatures in response to salinity exposure in two populations of an estuarine fish.

In estuary and coastal systems, human demand for freshwater, climate change-driven precipitation variability, and extreme weather impact salinity levels, reducing connectivity between mesohaline coastal fish populations and potentially contributing to genomic divergence. We examined gill transcriptome responses to salinity in wild-caught juveniles from two populations of Sacramento splittail (), a species of conservation concern that is endemic to the San Francisco Estuary, USA, and the lower reaches of its tributaries. Recent extreme droughts have led to salinities above the tolerance limits for this species, creating a migration barrier between these populations, which potentially contributed to population divergence.

Field testing a novel high residence positioning system for monitoring the fine-scale movements of aquatic organisms.

Acoustic telemetry is an important tool for studying the behaviour of aquatic organisms in the wild.VEMCO high residence (HR) tags and receivers are a recent introduction in the field of acoustic telemetry and can be paired with existing algorithms (e.g.

Demographic differences in diet breadth of Canada lynx during a fluctuation in prey availability.

Population dynamics of specialist carnivores are closely linked to prey availability, but the extent of variability in diet breadth of individual carnivores relative to natural variability in the abundance of their primary prey is not well understood. Canada lynx (Lynx canadensis) specialize on snowshoe hares (Lepus americanus) and exhibit cyclic fluctuations in abundance that lag 1-2 years behind those of snowshoe hares. Declining hare densities spur demographic changes in lynx, but it is unclear whether a corresponding increase in diet breadth occurs: (1) broadly across a lynx population; (2) only among individuals who are able to effectively switch to alternative prey; or (3) only among individuals who cannot capture sufficient primary prey.