In this release program there are two sets of data we are collecting to evaluate the success of the project: survival and the time it takes for the animal to establish a stable home range.
Our first female, P33, seemed to establish a stable home range of around 2 hectares after 22 days. This was regardless of whether the estimate was using only GPS den site co ordinates; only den site triangulation estimates; or triangulation estimates of den site and activity locations (although triangulation estimates did produce larger estimates of home range size).
The above graph shows the changes in home range size after release for P33 using den site GPS coordinates
The map above shows all the locations P33 (green stars = homed den sites; green circles = camera trap photos; red stars = triangulated den sites; and red circles = triangulated locations during activity).
P27, a larger male is currently has a home range size of 4.7 hectares. Over the first week he was showing much lower den site fidelity, moving every night. However, more recently he has been utilising den sites for two or three consecutive nights and the dens are a lot nearer. This insinuates that his home range is stabilising.
However, unlike the female P33, even if P27 use the same den site, he still appears to leave and then return. Last night we obtained camera trap photos of him leaving the den site at around 6pm and returning at around 9pm. With P33, if she used the same den site on consecutive nights, we never recorded her leaving the den, but changes in the radio signal suggested she was moving within the tree hollow.
At night we monitor activity by noting changes in the strength and/ or direction of the signal bearing, most nights the times we have concluded he is active using radio tracking accord with times the photos have been taken.
This photo shows P27 leaving his den site at 6.40pm and was photographed returning at 9pm. This matches what we concluded while we were camped 150m away listening to changes in the signal strength and direction.