EPOW - Ecology Picture of the Week

Koala Skull and Ear Tag

Koala (Phascolarctos cinereus), Family Phascolarctidae
Otway Range, Victora, Australia

Explanation:  While hiking the eucalyptus woodlands and hills of the Otway Range in Victoria, southeast Australia, my friend and I discovered this remnant of the icon of the region, a koala.  We searched but found only the skull, leading me to speculate that it might have been a victim of predation, with the rest of the body carted off to some feeding or storage location.  

This may have been an adult (we used the pen for scale, here).
  

Moreover, upon further search, we discovered something of high research importance:  an ear tag that had been implanted and worn by the koala as part of some study possibly to track movement or population status:

The ear tag we found by the koala skull.
The rod goes through the hole pierce in the ear.
Note we placed the pencil there for scale (koalas prefer to use pens, ha).
  

But first, we marked the location of the find on our GPS unit, so as to report the spot to conservation and research authorities, such as the Australian Koala Foundation, that offers instructions on what to do if you encounter a sick, injured, or dead koala, and when and how to call for help.  They do note that road injuries and roadkills do occur with koalas, which should all be reported. 

Inspection of the remaining dental structure revealed some wear
on the molars, potentially signifying that this koala had been
around for some time, wearing down the occlusal surfaces
of the teeth chewing its preferred food of eucalyptus leaves.

  
Moreover, the find of the ear tag was also of research importance.  Another group, the Koala Action Group QLD Inc, tracks koala tags and their "owners."  

However, we found this ear tag separated from the skull, so we could not tell which ear it belonged to.  Why is this important?  It is because male koalas are tagged in the left ear, and females in the right ear (because, as is said, females are always RIGHT).  

 
Acknowledgment:  My sincere thanks to Sandra Penman who, along with Dr. Trent Penman, hosted me during my visit, and who guided me in the woodlands of Otway to her research sampling locations where we made this discovery.