The cost and benefits of territorial tenure, and factors affecting mating success in male Antarctic fur seals

• Published in: Journal of Zoology
• Main Authors: Arnould, J. P. Y., Duck, C. D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1997
• Subjects: Antarc*; Antarctic; Antarctic Fur Seals; Arctocephalus gazella; Bird Island
• Online Access: http://dx.doi.org/10.1111/j.1469-7998.1997.tb05739.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1997.tb05739.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1997.tb05739.x; https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1997.tb05739.x

The timing, location and duration of territorial tenure, and the mating success and return rates of male Antarctic fur seals ( Arctocephalus gazella ) were measured over four consecutive breeding seasons (1984–87) on Bird Island (54°00'S, 38°02'W), South Georgia. Tenure duration (days) followed a heavily skewed, Poisson‐like distribution (median 13.08 days, maximum 75 days) and was positively related to the number of years of tenure (r s = 0.52, P < 0.0001). Mating success was also biased to a few individuals and was positively correlated to both duration of tenure (days) and the previous number of years in which tenure was achieved ( P < 0.0001 in both cases). The timing and location of territorial tenure had no measurable effect on mating success ( P > 0.05 in both cases). The probability of a male returning to hold a territory in the next year was not related to the number of years tenure that had been achieved ( P > 0.7) or to the level of mating success in the current year ( P > 0.15). It was, however, positively related to the duration of tenure in the current year ( P < 0.0001). The overall annual return rate was 43% which is not significantly different from the survival rate for the general male population and suggests that territorial tenure does not contribute to increased mortality in male Antarctic fur seals.