Saturday 18 January 2014

THREE-K

 
Three THOUSAND metres! That's how high our juvenile eagle Kuyurnpa has been flying! At that sort of altitude, she can hardly be called a baby any more. During the past week Kuyu has come on in leaps and bounds, climbing to greater heights each day, usually soaring at similar altitudes to her mother, who we have had GPS fixes on nearby. Kuyu's highest fix has been 6400m asl (above sea level), and although I am still unsure of the accuracy of these extremely high points, we know that points up to 3300m asl are definitely correct. This shows she has now become a highly confident flyer, riding thermal air currents and using the altitude reached as a starting point to glide (with no use of energy) across the scrub. Kuyu is well on the way to becoming an independent eagle. It's hard to believe this is the same bird that I removed from her nest 3 months ago!

Here is a short video simulation of Kuyu's 3-dimensional home range. The nest on which she hatched (shown by the pink dot labelled 'WTE-N66') is now a tiny speck below her. She has not (as far as we can tell) returned here, even to roost, since fledging at the beginning of November.
 


Kuyu 3K Video from Simon Cherriman on Vimeo.

Saturday 11 January 2014

Wallu Walkabout


No - your eyes do not deceive you! The long orange line connecting several red dots on the above map shows the largest movement made by any of our tracked eagles to date. The culprit is Wallu, who for six consecutive months has remained within his territory near the south-eastern corner of the Lorna Glen study area. This area is about 8km wide and is shown by the cluster of red dots above.

Today I checked the tracking data and it revealed that, around 12 noon on 9th January, he had paid a small visit to the far south-east, crossing the border of the property (white line), and returning to roost 'at home' again that night. He repeated this visit the next day, this time heading almost directly east, before returning. Then today, he left his home range around 10am and again headed south-east, crossing the Lorna Glen boundary around midday. When the next GPS fix was taken at 3pm, he was traveling at 30km/h along a creek line at a location nearly SIXTY KILOMETRES from his territory! The 4pm and 5pm GPS fixes show Wallu's return journey, which by 8pm had brought him right back home to a favourite roost at - guess where - 'the larder': a well-populated rabbit warren within his home range. You can have a closer look at the map by clicking the picture above.

We don't know why Wallu made this huge journey - perhaps he was looking for another mate, fighting over territory with a rival male, investigating food supply in other areas, or simply 'checking out the scenery'. Further tracking data will hopefully reveal if this type of movement is normal for an apparently sedentary breeding adult in the non-breeding season - or if it was just a random Wallu walkabout.