Hello, I am using the BBMM in adehabitat to to analyze GPS collar data and have two questions that I'm hoping someone can help me out with. I am pretty new to R and adehabitat and would very much appreciate any insight anyone can offer (and hopefully these questions are not too rudimentary). My concerns are as follows:
1) As I understand from Horne et al. 2007, Sig2 is the standard deviation of location error. However, I have used data from stationary collars to estimate location error and find that the data conforms to a bivariate distribution (either by normal or Laplace distributions, see McKenzie et al. 2008, Environ Ecol Stat [Online]), rather than a simple normal distribution. By log-transforming the data, it is possible to normalize this distribution and obtain sd values, but I wanted to verify that that is an appropriate method for obtaining the required standard devitation value for the BBMM. 2) I am hoping to get some clarification regarding the ltraj function and inclusion of missed fixes in the data set for the purpose of using the BBMM. More specifically, will the home range and UD estimation be affected by the ommission of missed fixes from the dataset. Before deciding on using the BBMM, I had removed missed fixes from my data set, and so I did some initial coarse-scale comparisons against data that included the missed locations. I didn't find noticeable differences in the UDs, and continued with analysis, but perhaps I made this decision with haste. I am wondering if it is necessary to reinsert the missed locations in the data set and redo the analysis. Thanks so much for your help. Andrea Andrea Maxie M.Sc. Candidate Trent University Peterborough, Ontario -- View this message in context: http://www.nabble.com/BBMM-questions%3A-Sig2-and-missing-locations-tp21461782p21461782.html Sent from the AniMov mailing list archive at Nabble.com. _______________________________________________ AniMov mailing list [email protected] http://www.faunalia.com/cgi-bin/mailman/listinfo/animov
