Egg-laying normally begins during early May to the first 10 days of June.
Late thaws are harmful to them since they allow too little time for the full breeding process, with particularly importance given to good food supply in May for adults, even more so apparently than food supply in July when young are being fed.
Late nests are possible cases of inexperienced pairs, low food supplies, bigamy or even replacement clutches.
The clutch is extremely variable in size averaging around 7–9, with up to 15 or 16 eggs recorded in extreme cases.
The clutch size very large relative to related species.
Mean clutch sizes were 7.5 in a sample of 24 in Hooper Bay (range of 5–11); 6.7 in a sample of seven from Barrow (4–9); 9 in a sample of a sample of 5 in Baffin Island; 9.8 on Victoria Island; 8.4 (in a sample of 14) on Elsemere Island; 7.4 on Wrangel Island and 7.74 in Finnish Lapland.
The average clutch size was 9.8 in a good year in Victoria Island while in a good year in Barrow the mean was 6.5.
The clutch is laid directly to the ground and are pure, glossy white.
An average egg is around 56.4 mm × 44.7 mm (2.22 in × 1.76 in) with a range of heights from 50 to 70.2 mm (1.97 to 2.76 in) and diameter of 41 to 49.3 mm (1.61 to 1.94 in).
Egg weights are around 47.5 to 68 g (1.68 to 2.40 oz), the median or average being 53 and 60.3 g (1.87 and 2.13 oz) in different datasets.
The average egg size is relatively small, about 20% smaller than Eurasian eagle-owl eggs and 8% smaller than great horned owl eggs.
Laying intervals are normally 2 days (41–50 hours mostly).
The laying intervals can range up to 3–5 days in inclement weather.
The laying of a clutch of 11 eggs can take 20–30 days, while a more typical nest of around 8 takes about up to 16 days.
The interval between the 8th and 9th eggs can be up to about 4 days.
Incubation begins with the first egg and is by female alone, while she is fed by her mate.
Egg-laying normally begins during early May to the first 10 days of June. Late thaws are harmful to them since they allow too little time for the full breeding process, with particularly importance given to good food supply in May for adults, even more so apparently than food supply in July when young are being fed. Late nests are possible cases of inexperienced pairs, low food supplies, bigamy or even replacement clutches. The clutch is extremely variable in size averaging around 7–9, with up to 15 or 16 eggs recorded in extreme cases. The clutch size very large relative to related species. Mean clutch sizes were 7.5 in a sample of 24 in Hooper Bay (range of 5–11); 6.7 in a sample of seven from Barrow (4–9); 9 in a sample of a sample of 5 in Baffin Island; 9.8 on Victoria Island; 8.4 (in a sample of 14) on Elsemere Island; 7.4 on Wrangel Island and 7.74 in Finnish Lapland. The average clutch size was 9.8 in a good year in Victoria Island while in a good year in Barrow the mean was 6.5. The clutch is laid directly to the ground and are pure, glossy white. An average egg is around 56.4 mm × 44.7 mm (2.22 in × 1.76 in) with a range of heights from 50 to 70.2 mm (1.97 to 2.76 in) and diameter of 41 to 49.3 mm (1.61 to 1.94 in). Egg weights are around 47.5 to 68 g (1.68 to 2.40 oz), the median or average being 53 and 60.3 g (1.87 and 2.13 oz) in different datasets. The average egg size is relatively small, about 20% smaller than Eurasian eagle-owl eggs and 8% smaller than great horned owl eggs. Laying intervals are normally 2 days (41–50 hours mostly). The laying intervals can range up to 3–5 days in inclement weather. The laying of a clutch of 11 eggs can take 20–30 days, while a more typical nest of around 8 takes about up to 16 days. The interval between the 8th and 9th eggs can be up to about 4 days. Incubation begins with the first egg and is by female alone, while she is fed by her mate.
Snowy owl