Quantifying the impact of sea ice coverage on the welfare of grey seal pups

Grantee: Daire Carroll

Institutions: University of Gothenburg, Sweden

Grant amount: $151,000

Grant type: Fellowship

Focal species: Grey seal (Halichoerus grypus)

Conservation status: Least concern

Research location: Sweden

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Project summary

This project will use historic necropsy assessment, including body condition indicators (size and blubber layer), cause of death, age, and parasite load, coupled with drone-based photogrammetry, to establish and validate welfare proxies. The project will subsequently establish and validate remote behavioral and body conditions in grey seals as a remote welfare assessment tool. The project will further seek to understand density-dependent welfare in relation to differences in environmental conditions by comparing cortisol levels from feces, behavior, and body condition of juvenile seals in land and ice breeding colonies at different seal densities. The combined information will be used to develop predictive models that can identify welfare risk factors and opportunities to mitigate them. Finally, the project will identify and propose opportunities to alleviate stress for juveniles during land breeding years to improve welfare. The project will demonstrate proof-of-concept for a combined population modeling and behavioral/health assessment approach that can be transferred to other species to understand risk factors for poor welfare and identify opportunities for correcting them.

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WellSeal: Non-invasive quantification of welfare in lactating harbour seals

Grantee: Jess Harvey-Carroll

Institution: University of Gothenburg, Sweden

Grant amount: $30,000

Grant type: Small grants

Focal species: Harbour seal (Phoca vitulina)

Conservation status: Least concern

Disciplines: Population ecology, animal behavior, animal welfare science

Research location: Sweden

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Project summary

Harbor seals require locations protected from adverse weather and other disturbances during the birthing season, when vulnerable pups are left on land while mothers forage. The limited availability of such sites leads to high intraspecific competition, in which larger seals are likely to dominate more desirable locations due both to their physical strength and their lower need to forage. Mothers must choose when and for how long to forage, leading to trade-offs between maternal and offspring welfare which may lay the foundation for the welfare of younger generations. Currently, little information is available on time spent foraging during the lactation period. As harbor seals are facing unprecedented stress from overfishing, seals are swimming increasingly large distances to obtain food. It is not known how this change affects the trade-off between maternal foraging and offspring care, and the resulting welfare of the pups. This project will use camera trap footage and state-of-the-art 3D modeling to non-invasively assess the influence of maternal welfare on the time spent away from the pups. Pup welfare during periods of maternal absence will also be assessed. Welfare will be assessed in terms of the Five Domains framework, based on individual body condition (health), an index of the optimality of their haul-out position (environment), and a record of positive and negative interactions (behavior). Such welfare assessment will be aggregated at a colony level to compare welfare between colonies with more and less access to food.

Why we funded this project

We funded this project because it seeks to evaluate welfare impacts of population density — likely a common cause of welfare issues — in a relatively abundant species, using a robust approach that is only possible thanks to the species-specific knowledge of the PI and her collaborators. For example, we value their use of image analyses to identify haul-out site suitability and welfare impacts on a fine spatial scale that takes into account both environmental and social factors. We also valued the focus on juvenile welfare and the conflict of interest that may arise between parent and offspring. Improving our understanding of the fundamental relationships between population density, parental care, and juvenile welfare will allow the results of this project to extend to other contexts.

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