Geographic variation in ringed seal growth rate and body size

• Main Authors: Ferguson, Steven H., Zhu, Xinhua, Young, Brent G., Yurkowski, David J., Thiemann, Gregory W., Fisk, Aaron T., Muir, Derek C.G.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2017
• Subjects: Arctic; Hudson; Hudson Bay; inuit; Pusa hispida; ringed seal; Sea ice
• Online Access: http://hdl.handle.net/1807/88443; http://www.nrcresearchpress.com/doi/abs/10.1139/cjz-2017-0213

We summarize geographical patterns in ringed seal (Pusa hispida Schreber, 1775) body length and girth growth using 3012 samples collected by Inuit hunters in the eastern Canadian Arctic, 1990-2016. Spatial structure was detected using cluster analysis of environmental variables separating a northern region in the eastern Canadian High Arctic and a southern region in Hudson Bay. The north was characterized by more fast ice, multi-year ice, greater snow depth, colder temperatures, and greater sea ice concentration in the spring seal breeding season. Hierarchical Bayesian models described length and axillary girth growth of northern seals as slower than in the south, reaching asymptotic size 5-7 years later. Northern females were larger than males (asymptotic length of 149 versus 140 cm, respectively) and both were larger than southern seals (males and females 126 cm). We conclude that environmental variation was best represented by regions rather than latitude, regional body size differences were driven by differential growth rates, and northern ringed seals may be characterized by reverse sexual size dimorphism. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.