Bank Swallows are widespread breeders throughout Alaska and also breed across the old-world. Thus it is not surprising that they are the most numerous Hirundine in the Pribilofs. Every year a few individuals appear in late May and the first week of June. In fall, starting in early August through mid September Bank Swallows typically arrive with every strong Easterly wind. Fall flocks over Webster Lake can often number more than a dozen individuals. No other brown-backed Swallow is likely in the Pribilofs, although the possibility of a juvenile Violet-green Swallow should always be kept in mind when sifting through flocks of Bank Swallows. Young Violet-greens are a grayer brown above, lack the dark breast collar of Bank Swallows and have white flank patches. Bank Swallows (and other swallow species) are most often seen flying above freshwater lakes (especially Webster Lake), or soaring along the cliff edges on the west side of the island.