Conducting assessments to understand the effects of changing environmental conditions on polar bear ( Ursus maritimus ) demography has become increasingly important to inform management and conservation. Here, we combined physical (2005–2007) and genetic (2017–2018) mark‐recapture with harvest recovery data (2005–2018) to estimate demographic rates of the Davis Strait polar bear subpopulation and examine the possible effects o...

The Arctic is a global warming ‘hot‐spot’ that is experiencing rapid increases in air and ocean temperatures and concomitant decreases in sea ice cover. These environmental changes are having major consequences on Arctic ecosystems. All Arctic endemic marine mammals are highly dependent on ice‐associated ecosystems for at least part of their life cycle and thus are sensitive to the changes occurring in their habitats. Understa...

Arctic food webs are being impacted by borealisation and environmental change. To quantify the impact of these multiple forcings, it is crucial to accurately determine the temporal change in key ecosystem metrics, such as trophic position of top predators. Here, we measured stable nitrogen isotopes (δ 15 N) in amino acids in harp seal teeth from across the North Atlantic spanning a period of 60 years to robustly assess multi‐d...

The harbour seal ( Phoca vitulina ) is the most widely distributed pinniped, occupying a wide variety of habitats and climatic zones across the Northern Hemisphere. Intriguingly, the harbour seal is also one of the most philopatric seals, raising questions as to how it colonized its current range. To shed light on the origin, remarkable range expansion, population structure and genetic diversity of this species, we used genoty...

The northwest Atlantic subspecies of gray seal ( Halicheorus grypus grypus ) has been increasing for more than a half century and has reestablished breeding colonies in Canadian and US waters. In 2016, visual, oblique, and vertical large‐format digital photographic surveys were conducted at all known breeding colonies in the northwest Atlantic. Total pup production in the northwest Atlantic was estimated to be 109,000 ( SE = 1...

Determining how marine predators partition resources is hindered by the difficulty in obtaining information on diet and distribution. Stable isotopes ( SI ) of carbon ( 13 C/ 12 C, δ 13 C) and nitrogen ( 15 N/ 14 N, δ 15 N) provide a two‐dimensional estimate of the dietary space of consumers; an animal's isotopic composition is directly influenced by what they consume and where they feed. Harp ( Pagophilus groenlandicus ) and...

A bstract Measurement of progesterone concentration in blubber was developed as a method to detect pregnancy in minke whales. Progesterone was extracted and quantified from blubber samples of minke whale carcasses by radioimmunoassay. Results showed a highly significant difference (almost 60‐fold) between blubber progesterone concentrations of anatomically determined pregnant females versus non‐pregnant female or male carcasse...