Geographical variation in temporal and spatial vocalization patterns of male harbour seals in the mating season

In the aquatically mating harbour seal, Phoca vitulina, oestrous females show marked differences in spatial and temporal distribution between geographical areas. This suggests that the males' display behaviour may also vary between areas. We recorded male vocalizations in two areas, the Moray Firth and Orkney, U.K. In the Moray Firth, females haul out on a few intertidal sandbars and travel along predictable routes to forage at sea. In Orkney, female haul out sites are much less influenced by tidal availability and females are much more dispersed. In the Moray Firth, males vocalized only during a short mating season, from 1 July to 12 August. Vocalizations varied significantly with the tide, the peak at high tide clearly coinciding with the period when most females were in the water. In contrast, vocalizations in Orkney were significantly related to both tidal and diel patterns. We suggest that the timing of male vocalizations reflects differences in female availability between sites. In the inner Moray Firth, vocalizations were heard throughout the females' range, whereas vocalizations in Orkney were heard only in two discrete areas. However, at both sites the density of vocalizing males was highest in narrow channels and/or along predictable female travel routes. Therefore, males clearly adapt their temporal and spatial behaviour patterns to variations in female distribution and density. These results suggest that male mating strategies in aquatically mating pinnipeds are more variable than was previously envisaged. Copyright 1999 The Association for the Study of Animal Behaviour.

[1]  M. Bigg.  Clines in the Pupping Season of the Harbour Seal, Phoca vitulina , 1969 .

[2]  G. Bartholomew.  A MODEL FOR THE EVOLUTION OF PINNIPED POLYGYNY , 1970, Evolution; international journal of organic evolution.

[3]  R. M. Sullivan.  Aquatic Displays and Interactions in Harbor Seals, Phoca vitulina, with Comments on Mating Systems , 1981 .

[4]  J. Buchwald,et al.  Individual differences in threat calls of northern elephant seal bulls , 1981, Animal Behaviour.

[5]  B. Stewart.  Diurnal hauling patterns of harbor seals at San Miguel Island, California , 1984 .

[6]  S. Allen.  MATING BEHAVIOR IN THE HARBOR SEAL , 1985 .

[7]  D. Demaster,et al.  DIEL HAUL-OUT PATTERNS AND SITE FIDELITY OF HARBOR SEALS (PHOCA VITULINA RZCHARDSI) ON SAN MIGUEL ISLAND, , 1987 .

[8]  Paul M. Thompson.  Timing of mating in the Common Seal (Phoca vitulina) , 1988 .

[9]  B. McConnell,et al.  SEASONAL AND SEX-RELATED VARIATION IN THE ACTIVITY PATTERNS OF COMMON SEALS (PHOCA VITULINA) , 1989 .

[10]  P. M. Thompson,et al.  Methods for estimating the population size of common seals, Phoca vitulina , 1990 .

[11]  D. Boness.  Determinants of mating systems in the Otariidae (Pinnipedia) , 1991 .

[12]  Ø. Wiig,et al.  Clines revisited: The timing of pupping in the harbour seal (Phoca vitulina) , 1991 .

[13]  D. Costa.  Reproductive and foraging energetics of pinnipeds: Implications for life history patterns , 1991 .

[14]  B. J. Boeuf,et al.  Pinniped mating systems on land, ice and in the water: Emphasis on the Phocidae , 1991 .

[15]  I. Boyd.  Environmental and physiological factors controlling the reproductive cycles of pinnipeds , 1991 .

[16]  W. Bowen,et al.  Mass and Energy Transfer during Lactation in a Small Phocid, the Harbor Seal (Phoca vitulina) , 1992, Physiological Zoology.

[17]  D. Siniff,et al.  Territorial behavior and breeding frequency of male Weddell seals (Leptonychotes weddelli) in relation to age, size, and concentrations of serum testosterone and cortisol , 1992 .

[18]  J. Temte.  Photoperiod control of birth timing in the harbour seal (Phoca vitulina) , 1994 .

[19]  R. Schusterman,et al.  Underwater acoustic displays and individual variation in male harbour seals, Phoca vitulina , 1994, Animal Behaviour.

[20]  B. L. Boeuf,et al.  Size, dominance and copulatory success in male northern elephant seals, Mirounga angustirostris , 1994, Animal Behaviour.

[21]  Paul M. Thompson,et al.  Changes in the distribution and activity of female harbour seals during the breeding season: implications for their lactation strategy and mating patterns , 1994 .

[22]  M. Fedak,et al.  Habitat use and diving behaviour of harbour seals in a coastal archipelago in Norway , 1995 .

[23]  W. Bowen,et al.  The Evolution of Maternal Care in Pinnipeds , 1996 .

[24]  M. Tasker,et al.  Aquatic predators and their prey , 1996 .

[25]  The diet and foraging ecology of harbour seals (Phoca vitulina) in the Moray Firth, Scotland , 1996 .

[26]  P. Thompson,et al.  Estimating harbour seal abundance and status in an estuarine habitat in north-east Scotland , 1997 .

[27]  P. Thompson,et al.  Distribution and activity of male harbour seals during the mating season , 1997, Animal Behaviour.

[28]  D. Coltman,et al.  Balancing foraging and reproduction in the male harbour seal, an aquatically mating pinniped , 1997, Animal Behaviour.

[29]  P. Thompson,et al.  MODIFICATION AND DEPLOYMENT OF A SONOBUOY FOR RECORDING UNDERWATER VOCALIZATIONS FROM MARINE MAMMALS , 1998 .

[30]  Reproductive strategies of male harbour seals (Phoca vitulina) , 1998 .

[31]  D. Coltman,et al.  Male mating success in an aquatically mating pinniped, the harbour seal (Phoca vitulina), assessed by microsatellite DNA markers , 1998, Molecular ecology.

[32]  D. Coltman,et al.  A multivariate analysis of phenotype and paternity in male harbor seals, Phoca vitulina, at Sable Island, Nova Scotia , 1999 .