Saturday, 14 December 2013

And What of Wallu?

Today marks the 6 month anniversary of the day I was successful in capturing an adult Wedge-tailed Eagle, a male we named ‘Wallu’. He was released in a healthy condition and monitored closely for the next few weeks to ensure he coped with his new backpack. Wallu has since remained in the same territory (which we have determined to be about 32km2 in size – quite small for the desert environment in which he lives), giving us amazing insights into his life. He has regularly been clocked at over two thousand metres above the ground, usually soaring but occasionally performing fast dives at 90km/h!
Here is a three-dimensional map showing the ~2700 GPS fixes recorded by Wallu’s PTT since June 2013:

The two ‘outliers’ shown above indicate possible errors in the tracking device’s accuracy: the one at centre top showed an altitude of ~6000m, and the point at far right is about 3km out of Wallu’s territory (as shown by the rest of the fixes). Both fixes may indeed be accurate, but given their location in context of the other points, I am treating them with caution.

So far this data gives a solid backup to what we already know about this species: adults are resident in a fixed territory throughout the year. But what I’m really keen to find out is whether they may leave their home range at any given time. Such information cannot be unveiled without being able to identify individuals, and is another thing to look forward to as our study continues!