Wednesday, June 6, 2012

Research Update #2 – June camera trials


Click on a photo to start the slideshow of full sized images.


















As you can see, the camera trap is quite something.  This has been a particularly exciting week and most of all because of the testing of an Ecotone BEV unit that I hope to use for the study.  This first unit needed to be evaluated before settling on a design.  With this trial a success, its now time to get another four of these cameras which will enable me to investigate the diet at five nests this year.

By using these cameras and photographing each item as it is eaten at the nest, this should be the most definitive method  for describing breeding diet (as opposed to bone collections, pellet analysis, or observations from a nearby hide).  Of course, we won’t be sure about what the adult male is eating on his hunting grounds or what they consume outside of their year of parenthood.  Luckily there is a long post-fledging period and as we have seen this year, juveniles that are two or three months out of the nest will still have their food delivered directly onto the nest, so this could well cover diet for most of the year.

With the support of Darryl, the landowner with the fortune of having this nest right above his house, this site in particular was chosen for the trial.  Because of Darryl’s interest, this pair has a well-known history.  The nest was first built in 1989! And since then one adult female, and one of the 9 juveniles produced were known to have been shot by anonymous locals.  Darryl keeps a keen eye on them, and in the last month this pair has been busily nest-building and occasionally copulating – promising signs for spring!

It was also a challenge to get back in the saddle, and on the rope.  Despite climbing many trees in Mauritius, the hurricane beaten forest there was a somewhat stunted canopy, and the highest pitch was at 27 meters.  Well the first climb for this project was probably 35 meters up.  It was a long slow grind to the top, forearm and thigh muscles burning!  Two hours later, having redirected the rope to an ideal fork for the maintenance climbs, and having positioned the camera three times over, while being somewhat distracted by an intimidating eagle glaring at me at eye level, I was back on terra firma.  Wonderful terra firma.










Four days later and I had to do it all again, time to switch out the small memory card for a 32 Gigabyte card.   A nice rope placement and a simple changeover with the unit meant that the climb was fast and efficient.  Having watched the eagles fly in with green pine branches that morning, and leaving together on their own accord, I was relieved that they were absent for the whole time I was roped in.  Getting to the ground and hastily downloading the data revealed 2,500 images in four days.  Many of these did indeed have an eagle or two in frame.  Initially one or both of the birds were irritated at this new box present at eye level.  This interest waned quickly, and we will know during the course of this extended trial how disruptive this effect might be. 

Best of all there was a stunning shot of the male with the pine branch.  I had just seen him fly in with the fresh nesting twig earlier that morning, and now I see him bent over placing the branch into the nest.



Yesterday morning Darryl sent me a text … 
 “the male just gave the female some prey, she is eating it on the nest - facing the camera.  I hope shes not too far back on the edge.”
This will be an impatient ten day wait until the extended trial is done and I can retrieve the data and see for myself!


Photo credits 7, 9, 10, 11 to Erin Wreford

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