Ontogeny of movement patterns in naïve grey seal pups inhabiting a complex continental shelf ecosystem.

Autor: Nowak BVR; Biology Department, Life Science Centre Dalhousie University, Halifax, Nova Scotia, Canada.; Population Ecology Division, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada., Bowen WD; Biology Department, Life Science Centre Dalhousie University, Halifax, Nova Scotia, Canada.; Population Ecology Division, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada., den Heyer CE; Population Ecology Division, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada., Lang SLC; Population Ecology Division, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada.; Northwest Atlantic Fisheries Centre, St. John's, Newfoundland, Canada., Lidgard DC; Biology Department, Life Science Centre Dalhousie University, Halifax, Nova Scotia, Canada.; Population Ecology Division, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2023 Sep 27; Vol. 18 (9), pp. e0290707. Date of Electronic Publication: 2023 Sep 27 (Print Publication: 2023).
DOI: 10.1371/journal.pone.0290707
Abstrakt: Most vertebrate offspring must transition from the relative security of parental care (nutrition and protection) to independent foraging. Offspring face many challenges during this critical period, particularly in species where parental care ends at weaning, such as the grey seal (Halichoerus grypus). We studied the development of movement behaviour in naïve grey seal pups from their first trips to sea to about five months of age. Twenty-five (12 males and 13 females) newly-weaned pups were fitted with satellite-linked GPS tags on Sable Island, Nova Scotia, Canada in January 2016. The influence of fixed effects (pup size, sex, week) and the random effect of pup identity on trip characteristics were examined. Movement behaviour was analyzed using a move persistence mixed-effects model. Habitat use was highly variable among individuals and covered much of the geographic distribution of the population. Unlike older juveniles, subadults, and adults in this population, most naïve pups used multiple haulout sites to begin and end trips. There was little evidence of area-restricted search behaviour during trips, suggesting that naïve pups were using an opportunistic foraging tactic that may result in more variable foraging success than that of older, experienced animals. Naïve pups made longer trips with longer haulout durations between them than observed for older greys seals. Males and females differed in some trip characteristics, but sex effects were small over the first few months of life. Offspring size at weaning was not a useful predictor of trip characteristics. Move persistence of grey seal pups was initially high and then decreased over time as individuals gained experience. Both intrinsic and extrinsic factors were influential on the movements of grey seal pups. Greater body length at weaning, longer duration spent on shore after weaning, shallower water column depth, and farther distance from shore were all associated with lower move persistence. Female grey seal pups had lower move persistence than males. Overall, the movements of naïve grey seal pups during the first few months of life were characterized by extensive exploration, but move persistence decreased over time suggesting they may be using an exploration-refinement foraging tactic.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2023 Nowak et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
Databáze: MEDLINE
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