. Atoll research bulletin. Coral reefs and islands; Marine biology; Marine sciences. 228 The Bridled Tern (Sterna anaetheta) Bridled Terns were not present in winter but bred on both islands during summer (Fig. 8). Like Common Noddies, they were easy to see at night and generally stayed still when spotted by dim light. There were relatively few nests on either island but the large number of roosting birds on Frigate in summer (Table 1) suggests that they were preparing to nest there. In the absence of other shelter commonly used by this species for nesting elsewhere (, rock crevices, under
. Atoll research bulletin. Coral reefs and islands; Marine biology; Marine sciences. 228 The Bridled Tern (Sterna anaetheta) Bridled Terns were not present in winter but bred on both islands during summer (Fig. 8). Like Common Noddies, they were easy to see at night and generally stayed still when spotted by dim light. There were relatively few nests on either island but the large number of roosting birds on Frigate in summer (Table 1) suggests that they were preparing to nest there. In the absence of other shelter commonly used by this species for nesting elsewhere (, rock crevices, under dead turtles), Bridled Terns on the cays of the Swain Reefs create small blind tunnels under the dense vegetation and lay their eggs there. This habit could significantly reduce the chance of gulls finding the nests. The denser vegetation on Frigate provided more suitable nesting habitat than occurs on Price. Numbers on Frigate were lower during the day when birds were away foraging, but increased dramatically at night. Numbers on Price were low at all times and actually decreased at night. Perhaps birds use Price as a daytime roost while fishing but roost at night on Frigate where they are preparing to nest. However, with only one exception, there were always more birds present in the vegetated zone of both islands than there were on nests (Table 1). There was a distinct preference for roosting in the vegetated zone regardless of island or time of the diel cycle. PRICE, JANUARY 1987 FRIGATE. JANUARY 1988 GO lOOOn £ (2 800- o [14 s 600- 2 . oc u. 400" O cz w 200". 0 400 800 1200 1600 2000 2400 TIME (HRS) Figure 8. Numbers of Bridled Terns counted at different times of day in summer on Price Cay and Frigate Cay. Nonbreeding Species Counts of species that were present on these islands but did not nest there are presented in Table 2. Unlike other species, the Least Frigatebird {Fregata ariet) was found at night but not by day. In winter there were momentary influxes of
Size: 2268px × 1102px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauth, bookauthorsmithsonianinstitutionpress, bookcentury1900
