Clines revisited: The timing of pupping in the harbour seal (Phoca vitulina)

摘要: The regional variation in the pupping season of harbour seal (Phoca vitulina) was reviewed using birth periods reported for 65 colony sites distributed over a range from 30.4d to 78.5d North latitude. timing P. v. vitulina not related latitude, but birthing concolor along eastern America exhibited latitudinal cline. richardsi varied three distinct patterns: (1) significant unidirectional cline extending between Baja California and west coast Washington; (2) cluster comprised Puget Sound, Washington Vancouver Island, British Columbia colonies which occurred an average days later than on coast; (3) northern Alaska did demonstrate Insufficient data were available analysis mellonae or stejnegeri. We found great among all colonies, with mean dates occurring as early 15 March late 3 September. Little existed north 50d. To south 50d, however, most could be attributed correlation latitude affiliation Washington-Vancouver geographic area. Clinal result from: variations selective factor perhaps gene exchange contiguous populations playing role smoothing variation; Mexico Washington, non-selective environmental variable, such photoperiod.