Jpy. Arnould et Cd. Duck, THE COST AND BENEFITS OF TERRITORIAL TENURE, AND FACTORS AFFECTING MATING SUCCESS IN MALE ANTARCTIC FUR SEALS, Journal of zoology, 241, 1997, pp. 649-664
The timing, location and duration of territorial tenure, and the matin
g success and return rates of male Antarctic fur seals (Arctocephalus
gazella) were measured over four consecutive breeding seasons (1984-87
) on Bird Island (54 degrees 00'S, 38 degrees 02'W), South Georgia. Te
nure duration (days) followed a heavily skewed, Poisson-like distribut
ion (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 succe
ss 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 l
ocation of territorial tenure had no measurable effect on mating succe
ss (P > 0.05 in both cases). The probability of a male returning to ho
ld 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 suc
cess in the current year (P > 0.15). It was, however, positively relat
ed to the duration of tenure in the current year (P < 0.0001). The ove
rall annual return rate was 43% which is not significantly different f
rom the survival rate for the general male population and suggests tha
t territorial tenure does not contribute to increased mortality in mal
e Antarctic fur seals.