Behavioural patterns of male South American fur seals (Arctocephalus australis) and their effects on mating success
Mating success of individual males in polygynous species varies extensively but the factors which affect it are not always clear. This study examined four behavioural parameters of individually recognisable, territorial, male South American fur seals, Arctocephalus australis, in Peru, and their consequences for mating success. The tenure patterns, territory characteristics, time budgets, aggression rates and mating success of up to 224 male fur seals were studied between 1992-1994. Mean day that territorial tenure began was 21st October, the number of tenures held ranged from 1-5, mean tenure duration was 9.7 days (CL=9-11 days) and mean total tenure duration was 13 days (CL=11-16 days). Significantly fewer males defended territories in 1993 than in 1992 or 1994 but timing, number and duration of tenures were similar. Males which held more than one tenure per season (multi-tenures) arrived earlier and remained ashore for longer but the duration of their individual tenures was similar to single tenure duration. Males arrived earlier and increased their total tenure duration in successive years. The number of tenures males held varied between years. Mean territory area was 35m2 (CL=28-44m2) and did not differ between years, single and multi-tenure males or seasonally. Seventy percent of territories provided access to water, varying between 0-92% of the territory. Territories classified as deep pool territories were significantly larger than all other types. High levels of site fidelity were shown both within and between years. Water habitats were favoured for copulations with selection being greatest for tide pools. Males spent 96% of their time resting, 37% of which was spent upright. Active time was spent interacting with females (3%). Interacting with males, locomotion in and out of water and other activities occupied 1% of their time. Time budgets did not vary seasonally or between single and multi-tenure males. Time spent active decreased significantly in subsequent years for males that returned in all 3 years. Increased time spent active was related to higher proportions of water in the territory and shorter total tenure durations.