Ecology of Aleutian Canada Geese at Buldir Island, Alaska 
by 
G. Vernon Byrd! and Dennis W. Woolington® 
U.S. Fish and Wildlife Service 
Adak, Alaska 98791 
Abstract 
The only known breeding population of the endangered Aleutian Canada goose (Branta canadensis 
leucopareia) was studied from 1974 to 1977 at Buldir Island, Alaska. Geese began arriving at Buldir 
in early May; laying peaked during the last week of May or early June. Most eggs hatched in late June 
or early July and goslings fledged by 21 August. Most geese left Buldir during September. Unlike many 
other populations of Canada geese, the Aleutian birds did not nest near water. Nest sites were on steep, 
densely vegetated slopes of the volcanic island, generally below 300 m elevation in two plant communi- 
ties dominated by tall grasses and forbs. Over 90% of the nests were successful and about 80% of the 
eggs hatched. Successful pairs raised an average of four goslings each to flight stage. The nesting population 
of geese at Buldir was estimated to be about 170 pairs. This goose population was increasing rapidly 
during 1976-77 as a result of hunting closures in California and the age composition was about 20% 
breeders and 80% immature birds. 
The endangered Aleutian Canada goose (Branta cana- 
densis leucopareia; Fig. 1) once nested on most of the Aleu- 
tian Islands as far east as the Islands of Four Mountains 
Group (Turner 1886; Clark 1910; Bent 1912; Jochelson 
1933: Murie 1959), in the Commander Islands (Stejneger 
1885), and in the Kuril Islands (Snow 1897; Fig. 2). As a 
result of predation by introduced arctic foxes (Alopex 
lagopus) in the Aleutian and Kuril islands and dogs in the 
Commander Islands, this subspecies was extirpated every- 
where except Buldir Island where foxes were never intro- 
duced (Murie 1959; Jones 1963; Jones and Byrd 1979). 
In 1974 a multifaceted program was initiated to restore 
the Aleutian Canada goose population to a non-endangered 
level (Byrd and Springer 1976; Springer et al. 1978). Be- 
cause of the lack of knowledge about this subspecies, the 
first requirements of the program were to determine the 
breeding biology, habitat requirements, and size and struc- 
ture of the remnant wild breeding population on Buldir. 
This paper summarizes the results of that study. 
Study Area 
Location 
Buldir (52°21'N, 175°56'E) is in the western Aleutian 
Islands, Alaska (Fig. 2). The 2,000-ha island, the most iso- 
lated of the Aleutians, is about 115 km from the nearest 
Present address: Aladdin Route, Box 160E, Colville, WA 99114. 
2Present address: 88115 Highway 101 N., Florence, OR 97439. 
neighboring island. Local place names used in the text are 
shown in Fig. 3. 
Physiography 
Buldir is the westernmost Aleutian volcano (Fig. 4) 
that was active in the late Quarternary or Recent time 
(Coats 1953). Characteristic physiographic features of the 
island are boulder-strewn beaches, talus slides, and volcanic 
peaks. The tallest peak, Buldir Eccentric, rises 655 m above 
sea level. A relatively flat alluvial deposit, Camp Valley, 
occurs near Northwest Point; otherwise the island’s interior 
is composed primarily of steep slopes and plateaus. Nearly 
vertical sea cliffs form over half the island’s 20-km-long 
coastline. The remainder of the coast consists of rockslides, 
earth slides, or steep vegetated slopes. Buldir has only one 
relatively large body of fresh water, Kittiwake Pond, with 
a 1.2-ha surface area. Other surface water includes five 
ponds less than 15 m in diameter and four small streams 
that flow all summer. Buldir is about 6.4 km long and 
3.2 km wide. 
Weather 
Weather near sea level at Buldir during the summers is 
typically cool, humid, cloudy, and windy. During the 
study, average monthly summer temperatures at the U.S. 
Weather Service station nearest to Buldir (Shemya Island, 
115 km distant) ranged from 3.2° C in May to 9.5° C in 
August. Our field records at Buldir indicated similar 
temperatures: average daily maximums and minimums 
