In closing in on completion of all of the 300 km of walking tracks in the Park (done just on 280 km!) I did the short 2 km (return) Predator Track (shown in the picture). This is not signposted, but is shown in Melway's Directory. It links the gated Bartlett and Mathias management roads, passing through a clearing which was once the site of a farm, in the 1940s.
After the Predator Track, I went along the Mathias Track, and was very surprised to meet up with a nice lybrebird. I managed to get one zoom image before the bird disappeared into the ferns! I did about 4 km in total.
The photos are at http://www.worldisround.com/articles/302431/index.html