Analysis of environmental correlates of sexual segregation in northern elephant seals using species distribution models

• Published in: Marine biology Vol. 161; no. 2; pp. 481 - 487
• Main Authors: Gomez, Jonatan J, Cassini, Marcelo H
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-02-2014; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: adults; Animal and plant ecology; Animal, plant and microbial ecology; Aquatic mammals; Bathymetry; Biogeography; Biological and medical sciences; Biomedical and Life Sciences; Climate change; cold; dimorphism; Distribution; Elephant seals; entropy; environmental assessment; Factor analysis; females; Foraging; Foraging behavior; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; Habitats; insulating materials; Internet; latitude; Life Sciences; Low temperature; males; Mammalia; Marine & Freshwater Sciences; Marine biology; Marine mammals; Maximum entropy; Microbiology; Mirounga angustirostris; Oceanography; Oceans; Physiological aspects; Sea water ecosystems; Seals; Short Note; Spatial behavior in animals; Synecology; temperature; Thermal insulation; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Zoology; California; Climatic Envelope; Sexual Segregation; Elephant Seal; Northern Elephant Seal; Spatial Segregation; Carnivora; Vertebrata; Mammalia; Spatial distribution; Geographic distribution; Analysis; Mirounga angustirostris; Sexual segregation; Models; Pinnipedia; Distribution range
• ISSN: 0025-3162; 1432-1793
• DOI: 10.1007/s00227-013-2337-y

Elephant seals are among the most sexually dimorphic and polygynous species of all mammals. Their foraging grounds occupy a wide area of the world oceans, where they show spatial segregation between males and females. The objective of this paper was to correlate female and male foraging distributions of Mirounga angustirostris with main climatic variables at a biogeographical scale. We used website and bibliographical sources to obtain information on adult elephant seal distribution and environmental predictors (surface and bottom sea temperatures, productivity and bathymetry) and three species distribution models [maximum entropy model, environmental niche factor analysis and based on climatic envelopes (BIOCLIM)] to predict the habitat suitability of ocean regions. BIOCLIM provided the best fit. Sea surface and bottom temperatures were the variables with the highest explanatory power for females, while bathymetry was for males. Predictive maps suggest that low temperatures constrain female, but not male, distribution at high latitudes. We suggest that large size increases foraging efficiency of males because, among other benefits, it augments thermal insulation, improving the use of cold, rich sectors of the ocean. Different thermoregulatory abilities between sexes due to size dimorphism should be a complementary explanation of sexual segregation in elephant seals.