Thursday, October 3, 2013

Don the technophile

Don is one year old!  It has been an exciting journey following this particular eagle, made possible from the start by constructing a makeshift nesting platform.  Granted it wasn't photographically aesthetic, but the eagles liked it.  And Victoria and Albert soon had a nest they were happy to use. The little crowned eagle chick(s) hatched on the 8 October 2012.  Twenty days later the monitoring camera was installed, and from that point the nest activities were observed in intimate detail

100,000 images later Dons development, and all the food he’d consumed in 5 months, had been recorded.  He fledged from the nest on 19 Jan, and has been tended to by his parents all this time.  We are not sure if he’s managed to hunt successfully yet, but his dependency is now lapsing its first year.  Recently some aggressive confrontations between the queen of this realm Victoria, and son Don have suggested he’ll soon no longer be welcome at home.  Sometime between 7 and 13 months old the young crowned eagles will be ousted from their parents’ territory.  Its time to travel the world, become self-employed and eventually invest in the housing market.  Don may have a tough time establishing a new territory; a raptors survival is most tenuous in its first few years, and he'll have to face many challenges.  It will be about four years before he’s man enough to breed himself. 

How far and for how long crowned eagles roam is still not clear and so, with the support and financial support of the Victoria Country Clue Estate management and residents, and the technology, knowledge, and advice from Ben at Raptor Rescue, we have been able to fit an Avi-Track solar-GPS telemetry unit to Don. Weighing 70 grams, it is 2.2% of his weight, while bulky, the box dimensions have to be tall to capture enough sun over his back feathers.  While these units have been used effectively on vultures, and many other large raptors, crowned eagles spent much of their time in the shadows of the forest so the solar powered units are going to be tested to their limits.  

The dispersal data that we record from Dons movements will be aiming to answer many still unanswered questions about the crowned eagles sub-adult years.  And most importantly we will be able to respond quickly to any suspected inactivity indicating injury or death.  Five juveniles born in 2011 were killed by various causes including a pellet gun, and three electrocutions.

Ferncliffe, where Don was captured on 26 September.  Photo Burkhard Schlosser 2013

Don showing interest in the trap.  Photo Burkhard Schlosser 2013

Ron Perks and Ben Hoffman assisting with the project.  Photo Burkhard Schlosser 2013

Threading the Avi-track GPS unit.  Photo Burkhard Schlosser 2013

The makeshift field lab.  Photo Burkhard Schlosser 2013

fitting the solar powered GPS - GSM device. Photo Burkhard Schlosser 2013

Fitting the harness.  Photo Burkhard Schlosser 2013

biometrics: inner talon 52.4mm. Photo Burkhard Schlosser 2013

keep clear of the pointy end. Photo Burkhard Schlosser 2013
Preparing to weigh Don, at 2,700g he is fit and healthy.  Photo Burkhard Schlosser 2013

Taking the hood off a few seconds prior to release.  Photo Burkhard Schlosser 2013

Lift-off.  Photo Burkhard Schlosser 2013

Up up and away.  Photo Burkhard Schlosser 2013

and cruising back to his perch for the evening.  Photo Burkhard Schlosser 2013

Its been time-consuming this week.  With GPS positions appearing on a private webserver exactly on schedule three times a day, I chased a few morning and noon fixes.  Its already dark by the evening fix, when Don should be settled in to roost, and finding him then is difficult.  Finding him anytime is difficult, but I did manage to hear him twice from the vicinity of the GPS location.

We watch in anticipation for Dons next move, maybe he'll leave soon, or he might even stay until this time NEXT year, when the Victoria and Albert will hopefully breed again and kick him out for good.  So it time to wish Don well for this next stage of his life.