I know that I'm not answering your main question, but I think that it is not correct to include a random effect with only two levels (wet - dry) in a model. There must be a reasonable number of random-effects levels, usually more than 4 (see,e.g., Gelman & Hill 2007).
In my opinion, you should try to include the "Season" as a fixed effect, evaluating directly its effect on your y ("Birds").
In my case, I have 22 random variables. So, after doing model averaging, how can I estimate the random variables so that I can make a formular of habitat selection by the species/