Predictor variables and model AIC values for the probability that a Magellanic penguin chick died in a storm at Punta Tombo, Argentina, 1983–2010 for models including nest characteristics.

We used multiple logistic regression, grouping on nest, with robust standard errors on 1063 chicks in 377 nests with 233 storms. We added nest characteristics to the best model of chick age and weather variables (Table 1). Type = nest type (burrow or bush), Quality = nest quality (good, average, or poor; see Materials and Methods), Orientation = nest-entrance orientation (N, E, S, W), k = number of parameters, AIC = Akaike’s Information Criterion, ΔAIC = the difference between AIC and the lowest AIC, LL = model log-likelihood, AIC weight = the probability that the model is the best model given the data and the set of candidate models. Pseudo R2 of the best model with nest characteristics was 0.57.