Friday, 20 April 2012

Catching a thermal

Our first GPS tagged Verreaux's eagle "Pop" has now been collecting and transmitting data for exactly two weeks. It has been quite incredible for me to see exactly what he has been up to. There are so many times in the field when an eagle I am watching disappears over a mountain ridge and I am left wondering just how far it has gone. I now can already see a much clearer picture of what a day in the life of a Verreaux's eagle is like. Here I can share with you some of the first high resolution data we have recieved. It covers 6 minutes, tracking the eagles position every 3 seconds. The upwards spiral in the picture started at 14h04, and the bird took three minutes to gain height from an altitude of 1309 m to 1663 m, and its climb rate was 1.97 m/sec. The long glide covers 3.7 km, and lasted three minutes, at a speed of 22 m/s.
This project is a partnership between the Animal Demography Unit and  a team of researchers who developed the tag we are using (UVA-BiTS) at the Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam (UvA) in the Netherlands. I would like to take this opportunity to thanks the team, in particular Prof Willem Bouten, for all of their hard work and their willingness to give their time and expertise to make this happen. 

Monday, 16 April 2012

Nest Cameras

This year will be deploying nest cameras on selected nests in the Sandveld and the Cederberg. The main purpose of this is to compare the prey species which are brought to the chick while it is on the nest. The cameras will also give us useful information such as exact fledging date which is difficult to determine when you are monitoring so many nests!
Last year the Cederberg Cellars sponsored a live-feed camera which will be redeployed this season. In addition we want to put up at least 6 motion sensing cameras. We have chosen to use the Bushnell camera trap for its prolonged battery life and infrared flash. Now we just need the funding... 
Sponsorship of a nest camera will cost R3000 each. We will then put up the camera and when it comes down at the end of the season we will send you the best shots which will record the growth of the chick and highlights of the season. The cameras will make a big contribution to quantifying variation in the diet of the Verreaux's eagle in the two study areas and we will be very grateful for any support, for more information please contact Megan directly at blackeagle@capeleopard.org.za 

Wednesday, 11 April 2012

First GPS deployed


I have spent the last three weeks working with Victor Garcia from the Spanish Ministry of Environment during what has been a period of intensive efforts to catch and GPS tag adult Verreaux’s eagles . It has been a long build up and after many early starts, long days and failed attempts we finally caught our first adult Verreaux’s eagle in the Cederberg during the afternoon of Friday 6th April. This was a moment which I have been dreaming about for more than a year and having the eagle in my hands is a moment I will never forget.
We believe that the eagle is the male of the pair, although we cannot yet be certain. He was is a very good condition and weighed in at 3.4kg with a wingspan of 2.2m.
In collaboration with a team of scientists at the University of Amsterdam we are using a 40g GPS tag. The tag was mounted on the bird with a Teflon harness and will be recording data up to every 3 seconds.  in order to better understand the habitat use and hunting techniques of these birds in contrasting environments.  The whole capture and tagging went smoothly and the eagle was released again after 45minutes. Upon released it gave us the pleasure of watching it’s magnificent flight as it circled around the valley before rejoining it’s mate.
The process would not have been possible without the generous assistance of staff from Eagle Encounters who happily joined us for the field work. I would also like to send a big thank you to Donkies Kraal for accommodating the team while we were in the Sandveld, even when we were rained out of field work and needed a place to stay with no notice! As always I am also grateful to the Cape Leopard Trust and my friends at Driehoek Tourist Farm for their support and enthusiasm.