Logistic regression models of variation in avian influenza virus (AIV) seroprevalence for northern pintails, sampled in Alaska, USA, 2009.

Models examine the effects of location (site), while controlling for sex and age (adult vs. subadult).ak = number of parameters in model.bThe best approximating model has the lowest Akaike's Information Criterion (AIC) value and the highest model weight (ωi), relative to others in the model set.