3.2 Survival
The probability of survival was variable at both colonies, ranging from
0.62 to 0.89 at Stony Point, and 0.65 to 0.87 at Robben Island. Overall
survival (± SE) was slightly higher at Stony Point (0.82 ± 0.01) than
Robben Island (0.77 ± 0.02) based on a constant model. However, the best
supported survival model (model B22, Table A3 in the appendix) contained
an interaction between sardine spawner biomass WoCA and colony; the
relationship was positive at Robben Island, but negative at Stony Point
(Figure 3). There was some support for an interaction between time and
colony (model B32, Table A3 in the appendix), but this model produced a
higher QAICc and contained more parameters, and so was not retained as
the best model. Some support was shown for an additive effect of state
on survival (model B24, Table A3 in the appendix), with breeding
individuals exhibiting slightly higher survival rates, but this was not
retained in the best model.