Hello MARMAM community, On behalf of my co-authors, I am excited to announce our new publication regarding the isotopic niches of gray seals in the Canadian Journal of Zoology. The abstract is provided below.
Although it is often assumed that individuals in generalist populations are equivalent, recent research indicates that individual dietary specialization can be common in marine predators. Gray seals (*Halichoerus grypus* (Fabricius, 1791)) were considered locally extinct in United States waters by 1958 but have since recolonized the region. Although considered generalists, less is known about gray seal foraging ecology in the United States. To address this, we used carbon and nitrogen stable isotope analyses to investigate the foraging niches of adult gray seals in Massachusetts, USA. We examined skin, fur, and blood components to investigate seasonal variability and individual consistency in foraging niches, and serially sampled vibrissae to quantify the degree of individual foraging specialization in this population. Our results suggest that seals shift from coastal foraging habitats before molt to offshore habitats after molt, with a coincident shift from higher to lower trophic-level prey. Adult gray seals also exhibited individual consistency in foraging niches independent of population-level shifts and reflect a generalist population composed of individual foraging specialists. These findings serve as a baseline for subsequent research on gray seals in United States waters that could help to determine the mechanisms which promote individual specialization in this population. The paper can be found at this URL: https://doi.org/10.1139/cjz-2019-0032 . If you cannot access the paper, please feel free to email me at keith.hernandez2...@gmail.com. Best, Keith -- Keith M. Hernandez, MS PhD Candidate, Marine & Coastal Trophic Ecology Lab 1243 Energy, Coast & Environment Building Louisiana State University Baton Rouge, LA 70803
_______________________________________________ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
