[R] logistic regression with repeated measures for species-habitat associations

Ben Bolker bbolker at gmail.com
Wed Jul 21 00:30:00 CEST 2010


Maureen Ryan <meryan <at> ucdavis.edu> writes:

> 
> Hi,
>      I have three years of species presence/absence data for a set of ~100
> ponds, with a list of associated habitat characteristics (park, vegetation,
> hydroperiod, etc.).  The datasets differ slightly by year because some ponds
> were dry in some years and not in others.  My goal is to look at habitat
> associations for a couple focal species.
> 
> For each year, I have a data table that looks like (an expanded version of)
> this:
> 

 [snip]

  Maureen,
  
  I think this is a generalized linear mixed model with binary
outcomes, with fixed effects for the habitat variables, year, and
(possibly) the interaction of habitat by year, and with ponds
as random effects.  I would recommend either lmer (in the lme4 package)
or MCMCglmm (in the package of the same name), and I might recommend
also that you visit the r-sig-mixed-models mailing list with additional
questions ...
   Missing data should not be a big problem.

  Ben Bolker



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