I have used kernelUD from adehabitatHR to estimate kuds for several animals. I then used kernel.area(x,percent=c(50,95),unout="m2",standardize=F) to obtain the kud50 and kud95 areas for each animal. However, when I compare the given values with the values for kud95 obtained from getverticeshr(x, 95,unout="m2") there is a large difference in all animals.
Why do I get different values?
After carefully reading the pdf on adehabitatHR I found an answer
"Note that the home-range sizes returned by this function are slightly different from the home-range size stored in the SpatialPolygonsDataFrame returned by the function getverticeshr. Indeed, while the former measures the area covered by the rasterized home range (area covered by the se t of pixels of the grid included in the home range), the latter measures the area of the vector home range (with smoother contour). However, note that the difference between the two estimates decrease as the resolution of the grid becomes finer."