PERCENT OF CLUTCHES 
MAY 
Fig. 7. Distribution of onset of laying dates for Aleutian Canada 
geese at Buldir Island, Alaska, 1974-76. 
Breeding Phenology 
Mean onset of laying ranged from 25 May (1974) to 30 
May (1975). All clutches were initiated within a 16-day 
period in 1974 and within an 11-day period during the late 
1975 season. Onset of laying extended for 25 days in 1976, 
but 92% of the clutches were initiated within an 18-day 
period (Fig. 7). The ranges in initiation dates, except in 
1975, were generally longer than those observed for Canada 
geese farther north, similar to those at nearly the same lati- 
tude, and shorter than those farther south (MacInnes 1962; 
Vermeer 1970; Hanson and Eberhardt 1971; Mickelson 
1975; Bromley 1976; Raveling and Lumsden 1977). In 1975 
the range was similar to that of geese nesting 8-9° farther 
north. On the Yukon-Kuskokwim Delta, Alaska, B. c. 
minima began nesting earlier in 1974 and 1976 than in 1975 
(Dau and Mickelson 1979), and on the Copper River Delta, 
Alaska, B. c. occidentalis nested 10 days earlier in 1974 than 
in 1975 (Bromley 1976). 
Extensive snow cover, low temperatures, and violent 
storms at nesting areas delay the onset of laying in northern 
breeding geese (Cooch 1958; Mickelson 1975; Raveling and 
Lumsden 1977; Cooper 1978). The usual effect of a late 
spring at northern latitudes is to shorten the length of the 
nesting period (Ryder 1972; Mickelson 1975) as it did at 
Buldir. 
The presence of snow during nest-site selection would 
probably delay nesting only if it covered the nest site. Else- 
where Canada geese selected nest sites from the first snow- 
free areas (MacInnes 1962; Mickelson 1975; Bromley 1976). 
If it is assumed that this phenomenon occurred at Buldir, 
snow cover was not a significant influence on the timing 
of laying, but it probably affected the distribution of nests 
(see Habitat Use). 
Because no major storms occurred during the period of 
nest-site selection and laying during our study, tempera- 

1974 (N=20) 
PERCENT OF NESTS 

7-9 «10-12 
JUNE 
Fig. 8. Distribution of hatching dates for Aleutian Canada geese 
at Buldir Island, Alaska, 1974-76. 
ture may have been responsible for delayed laying in 1975. 
No records of temperature during the first 3 weeks of May 
are available for Buldir, but data from Shemya Island indi- 
cate that May temperatures in 1975 were lower than in 1974 
and 1976. Furthermore, the 1975 average for May was 
raised by warm weather during the last week of the month. 
At Buldir this period was also warmer in 1975 than in the 
other 2 years. An additional indication of the difference 
in temperatures is the last date freezing temperatures were 
recorded: 1 May 1974 and 4 May 1976, compared with 
25 May 1975. 
The incubation period was recorded to the nearest day 
for only three nests at Buldir: 27, 28, and 29 days. Aleutian 
Canada goose eggs hatched after 27-28 days (average) in 
incubators (F. B. Lee, personal communication). Average 
incubation periods for other Canada geese ranged from 26 
to 28 days (Bellrose 1978). 
The average hatching dates at Buldir for 1974, 1975, and 
1976 were 27 June, 3 July, and 29 June, respectively. Most 
nests hatched from 19 June to 6 July in 1974 and 1976, but 
from 28 June to 9 July in 1975 (Fig. 8). Thus, the nesting 
season (first egg laid to the last egg hatched) was 45-51 days 
for Aleutian Canada geese. Raveling and Lumsden (1977) 
discussed nesting periods relative to the size of the goose 
and the nesting latitude. The Buldir birds nest in about the 
length of time expected of small Canada geese, using more 
days than populations at higher latitudes and less than those 
farther south (cf. Raveling and Lumsden 1977). 
Post-hatching Movements 
Soon after hatching, Aleutian Canada goose families 
moved from nest sites to brood-rearing areas which were 
generally at higher elevations than the nesting areas (see 
Habitat Use), and within 1.5 km of their nests. Similar, 
but generally longer, movements of broods away from nest 
