Evaluating habitat use when occupancy is high

questions concerning analysis/theory using program PRESENCE

Evaluating habitat use when occupancy is high

Postby jluscie » Mon Dec 10, 2007 12:38 pm

We’re interested in evaluating habitat use of a few species that have naïve occupancies of >0.80. Is it still feasible to use Program Presence to model habitat use with covariates for these species with high naïve occupancies??

Thanks,

Jason D. Luscier
Dept. of Biological Sciences
University of Arkansas
Fayetteville, AR 72701-1201
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Postby darryl » Mon Dec 10, 2007 6:34 pm

Jason,
As feasible as using any other method such as standard logistic regression; nothing is likely to do a really good job if you're getting near 100% occupancy. You either need to think about adjusting what you're defining as your sampling unit (making it smaller will decrease occupancy) or consider switching to something more like abundance rather than just presence/absence.
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Postby dhewitt » Tue Dec 11, 2007 1:24 pm

Jason,

You might consider the multi-state models that are now in Presence (and apparently in MARK as well) and using some measure of local abundance as a classification for state. AFAIK there is no clear guidance on how/when this will help, and it won't be any use if you don't have measures of local abundance. But, worth considering if you do.
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