Northwest Pt. 



Fig. 11. Distribution of goose nests at Buldir Island, Alaska, 
1974-76. Black dots mark nest locations, stippled areas are un- 
vegetated slides, cross-hatching indicates the approximate extent 
of the Upland Short-plant association, in contrast to the Lowland 
Tall-plant association where no cross-hatching occurs. 
(average, 31.4 cm tall during late incubation). Additionally, 
over 60% of the nests had a depression of at least 0.5 m 
within 2 m of the front of the nest, which increased visibility. 
Visibility has been recognized by others as an important 
factor in nest site selection by Canada geese—e.g., B. c. 
occidentalis selected areas of above-average plant densities 
for nesting except in characteristically dense plant com- 
munities where they preferred sites with less than average 
density (Bromley 1976). 
Aspect. —Nesting success was lowest on north-facing 
slopes where the fewest nests were found (Table 4). The 
relatively high abandonment by birds nesting on northern 
exposures may have been related to weather. These areas 
were more often exposed to severe spring storms, and snow 
lingered longest there, resulting in less vegetative cover early 
in the season. 
The only significant difference revealed in a compari- 
son of the hatching success of nests on different aspects was 
lower (P < 0.05) success on eastern and southern slopes than 
on western slopes. This difference is inexplicable and may 
have been related to factors other than aspect. 
Elevation. — Nests ranged from 30 to 320 m in elevation, 
indicating a broad use of available habitats. The lowest 
available nesting habitat was usually over 25 m elevation, 
and areas above 300 m were usually unavailable for nesting 
because of persistent snow cover. 
Above 300 m elevation, a smaller percentage of nests 
seemed to be successful than at lower elevations, but the 
sample size of high nests was small (Table 4). No signifi- 
cant differences were found in hatching success in nests at 
different elevations. 
Nesting Density 
In 1975 all 45 goose nests we found were in the beach 
11 
Table 4. Nesting and hatching success of Aleutian Canada 
goose nests with different slopes, aspects, and elevations 
at Buldir Island, Alaska, 1974-76. 
Percent Percent 
Habitat Percent nesting hatching 
characteristic of nests success success 
Slope’ (n = 128) 
0-10 17 95 79.4 + 4.64 
11-20 09 73 70.8 + 8.4 
21-30 23 86 79.2 + 3.8 
31-40 42, 89 83.8 + 2.7 
41-50 09 100 92.8 + 3.38 
Aspect> (n = 135) 
338-022 N 09 75 87.6 + 5.4 
023-067 NE 13 91 85.6 + 3.3 
068-112 E 10 92 71.6 + 6.7¢ 
113-157 SE 22 86 82.8 + 4.4 
158-202 S 22 86 75.1 + 4.4 
203-247 SW 14 94 85.5 + 3.8 
248-292 W 08 100 91,0 + 4.08 
293-337 NW 03 100 85.0 + 9.6 
Elevation® (n = 142) 
0-60 13 90 87.6 + 4.2 
61-120 35 90 82.2 + 3.1 
121-180 25 92 81.4 + 3.3 
181-240 16 87 81.7 + 4.9 
241-300 07 90 15.3.4 5.7 
301-360 03 75 72.3 +12.7 
@Angular degrees from horizontal. 
bIn 44° angular segments centered on compass point. 
‘In meters above sea level. 
dMean + standard error. 
eSignificantly different (student’s “t-distribution,” P = 0.05). 
rye-umbel and beach rye-umbel-fern communities, and 
in 1976, 97% (65 of 67) of the nests were in the same com- 
munities. Of the two communities, beach rye-umbel was 
more widespread at Buldir and contained about 75% of 
the nests (Table 5). 
In 1976 an estimated 138 pairs of geese bred on Buldir 
(see Population Size and Structure). 1f it is assumed that 
133 nests (97% of the total) were in the beach rye-umbel 
and beach rye-umbel-fern communities and were dis- 
tributed in the relative proportions indicated by the sam- 
Table 5. Estimated density of goose nests in preferred plant 
communities at Buldir Island, Alaska, 1975-77. 
Percent Estimated 
of number Surface Nests 
combined of nests area per 
Community area 1976 (hectares) hectare* 
Beach rye-umbel 58.7 100 288 0.35 
Beach rye-umbel-fern 41.3 33 203 0.16 
Total 100.0 133 49] 0.27 
aMean nest density per stratum (Column 2 divided by Column 3). 
