aKDE for multiple populations of animals with multiple individuals

[Oliver Holt]

Hey Chris,

I'm wondering what the best approach is to generating aKDEs for thirteen unique caribou populations that each have >20 individuals collared caribou within each population. Essentially, each population's aKDE will be informed based on the fixes from the individual caribou within the population. 

Thanks! 

[Christen Fleming]

That would be the new population KDE function ?pkde  on Github, which I will be presenting at TWS this year. PKDE was derived and implemented for exactly this task.

Best,

Chris

[Maria Bogdanova]

Hi Christen, 

I and colleagues are working with tracking data from four seabird species over several years, so have a similar query: we have so far produced individual UDs and then ‘annual population UDs’ using pkde. However, we also need to generate a population UD across years. For that, we thought the best way would be to use the individual UDs of all birds tracked during the study period but for two of the species we get the errors below (for the other two it worked fine):
1) Error in UD[[i]]$weights %*% DEN : non-conformable arguments
2) Error in gridder(t, z = cbind(weights), W = F, dt = dt, lag = lag, FLOOR = FLOOR,  : dims [product 1012] do not match the length of object [3632],
with the numbers within the square brackets varying between datasets (i.e. the one here is just an example).
I’m not sure what causes the errors as the annual UDs were generated without issues. Any thoughts on what may be causing these and how to resolve them would be hugely appreciated.
Also, we were wondering if it's ok to generate the UD across years using the annual population UDs instead of individual ones, again with pkde? 

Many thanks, Maria

[Christen Fleming]

Hi Maria,

If that is happening on a recent version of the package from Github, then please send me a minimal working example (data + script) and I will make sure this gets fixed.

Best,

Chris

[Oliver Holt]

Hi Chris,

Can you send me a link to the PKDE gitub? I struggled to find it. Thanks!

[Christen Fleming]

Hi Ollie,

remotes::install_github("ctmm-initiative/ctmm")

Best,

Chris