mask overlap among sessions in different states

questions concerning anlysis/theory using program DENSITY and R package secr. Focus on spatially-explicit analysis.

mask overlap among sessions in different states

Postby jhumm » Fri Jan 10, 2020 8:05 pm

Hello phidot community!

I am analyzing 2 bear hair datasets collected at different years in different trapping grids. The plan is to pool the data in a multisession analysis, but I've found what might be a problem with making the habitat masks. The trapping grids border each other, and at some points along the transition between the year 1 grid and the year 2 grid, the halfway point between grids is less than 7km. Parameter estimates from previous data suggest it would be unwise to make such small buffers around my trapping grids, but making them larger would mean overlapping habitat masks. I would derive density by using region.N for a clipped portion of each mask in order to mitigate the overlap post-analysis.

Assuming no animals were caught during both years, would overlapping masks cause any issues with overrepresentation of density covariate data in the models? I would think not, given the previous assumption, but I'm not sure.

Thanks,

Jake
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Re: mask overlap among sessions in different states

Postby murray.efford » Sun Jan 12, 2020 12:53 am

Perhaps you're overthinking this. I don't see any problem. I don't quite understand how you plan to use region.N to compute density (?!), or how the covariates come into it, but I think you're safe. Worst case might be some slight underestimation of confidence intervals.
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Re: mask overlap among sessions in different states

Postby jhumm » Mon Jan 13, 2020 11:02 am

Shoot, meant to type 'abundance' there. Thanks for the reply!
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