[R-sig-Geo] Using BA to estimate home range overlap

[Katie Stopher]

Hello,

I am trying to use kerneloverlap from adehabitat to estimate overlap 
between the home ranges of red deer. For what I want to use the home 
range overlap for, I would like the overlap to take into account the UDs 
of the animals, but also to range between 0 and 1. From my reading of 
Fieberg and Kochanny (2005), using the BA method should do this.

My code is fairly straightforward:

xy<-locations[,c('Easting','Northing')]
id<-locations[,c('Code')]
overlap<-kerneloverlap(xy, id, "BA", 65)

But the results are surprising: in particular, some pairs of individuals 
have an overlap greater than one- up to above 2 in some cases. Can 
anyone explain to me why this might be?

Many thanks, and my apologies if I have missed something obvious in my 
reading of the help pages!

Thanks,

Katie Stopher

-- 
Katie Stopher

PhD Student, Wild Evolution Group,
Institute of Evolutionary Biology,
University of Edinburgh,
King's Buildings,
West Mains Road,
Edinburgh,
EH9 3JT


http://wildevolution.biology.ed.ac.uk/jpemberton/KatieStopher2.html

-- 
Katie Stopher

PhD Student, Wild Evolution Group,
Institute of Evolutionary Biology,
University of Edinburgh,
King's Buildings,
West Mains Road,
Edinburgh,
EH9 3JT


http://wildevolution.biology.ed.ac.uk/jpemberton/KatieStopher2.html