Table 2. Summary of the demographic parameters (±SE) used for the post-breeding population model for razorbills breeding in Atlantic Canada, 1995–2008. Productivity is the mean number of young fledged per pair.

Parameter Gannet Islands Machias Seal Island Sources
Population size (breeding pairs) 9808 550 2,3
Juvenile survival (age 0–2) 0.482±0.033 0.778±0.041 6
Annual survival (age 3–6) 0.970±0.030 0.912±0.052 6
Annual adult survival (age 7+) 0.890±0.053 0.967±0.028 6
Age at first breeding (yrs) 4.40±0.130 3.88±0.130 5
Proportion of breeders
1 yr old 0.00 0.00 5
2 yrs old 0.04 0.02
3 yrs old 0.25 0.32
4 yrs old 0.49 0.83
5 yrs old 0.73 0.94
6 yrs old + 1.00 1.00
Productivity 0.390±0.055 0.562±0.041 1,4
Hunting mortality 2159 0 this study

1Bowser et al. 2009, 2Chapdelaine et al. 2001, 3Grecian 2005, 4Lavers and Jones 2007, 5Lavers et al. 2008a, 6Lavers et al. 2008b.
Approximate number of razorbills shot from the Gannet Islands based on the number of murres harvested in 2001–2003.