The Return to the Mainland of Some Nocturnal Passerine Migrants over the Sea

The vegetation at the banding station is generally less than 10 feet high, which facilitates the capture of large numbers of birds in mist nets.Nets were placed east-west along fishermen's paths on the bay side, across the path of northward-flying migrants, and were in operation 24 hours a day from 30 August to 26 September 1959 and from 26 August to 11 September and from 14 September to 1 October 1960.Nets were checked for birds between about 0700 and 2000 hours because pre-dawn and post-sunset net checks were unproductive.The number of nets varied from day to day, 31 to 103 in 1959 and 13 to 67 in 1960.The varying number of nets affects fluctuations between days but not fluctuations during the day.Of the information recorded when a bird was captured, only the times of release (in 1959) and capture (in 1960) are considered in this paper.The time of release was usually within one hour of capture.Five families accounted for about 85 percent of all passerines captured (Table 1).Of these the Turdidae, Vireonidae, and Parulidae are considered in this paper because Gray Catbirds (Dumetella caroli•ensis), Rufous-sided Towhees (Pipilo erythrophthalm•s), and Song Sparrows (Melospiza melodia), which are common breeding species at Island Beach, make up a large porportion of the other two families.Casual examination of the data on the other migrant species suggests that the conclusions derived from analysis of data on the thrushes, vireos, and warblers are probably applicable to all nocturnal passerinc migrant species captured at Island Beach.