Chapter I Intro & Objectives - SPREP

PHOENIX ISLANDS PROTECTED AREA MANAGEMENT PLAN
Chapter III. Background, 3. Terrestrial Resources
Draft 1 March 2007
Ashmole (1963) noted that Phoenix and Line Islands sooty terns, Sterna fuscata, had a very
different molt program than sooty terns elsewhere. Birds from the Line and Phoenix Islands
have two breeding periods each year. With a six month breeding cycle, some individuals
underwent a complete molt, but others only replaced some of its primaries and secondaries
from one breeding cycle to the next.
From 1963 to 1965, as part of the Pacific Ocean Biological Survey Programme of the
smithsonian Institution, periodic biological surveys of the Phoenix and Line Islands were
conducted (Clapp and Sibley 1967). These surveys included bird surveys.
Clapp (1968) noted that there were discrete differences in the fall migrations of the sharptailed
sandpiper, E. acuminata, and the pectoral sandpiper, E. melantos to the Phoenix
Islands. E. melantos was observed in September and E. acuminata observed in November.
Sibley and Clapp (1967) reported the lesser frigatebird, Fregata ariel, bred on many islands
of the Phoenix Islands. They estimated a population of 70,000 breeding birds in the Phoenix
Islands (including Howland) (see Table III-3.17 below). Almost all leave the Phoenix
Islands during the non-breeding period (December to April).
Table III-3.17. Breeding status and populations of lesser frigatebirds
(source: Sibley and Clapp 1967)
Breeding
Island Location Present status Nest site Population Population
In 1963 and 1964, 13,027 nestlings and 146 adult lesser frigatebirds were banded on
Howland, McKean, Rawaki (Phoenix), and Enderbury (Sibley and Clapp 1967). Band
recovery data indicated that 74 percent of young lesser frigatebirds were caught over 2,000
miles from their birth island. Thirty one percent were caught 6,437 to 8,047 km (4,000 to
5,000 miles) away. Figure III-3.3 illustrates the probable dispersal path of lesser frigatebirds
from the Phoenix Islands. Adult lesser frigatebirds may not disperse as widely and do the
young.
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