With thanks
Another breeding season has come
to an end for the Black eagles which gives me time to reflect on another season
of research.
For the eagles it was certainly a
tough year in the Cederberg – With only 11 pairs attempting to breed and only 6
young fledging. Must note here that since the helicopter survey there are of
course many nests which are not included in these statistics. Nevertheless it
certainly highlights the high rate of failure, mostly caused by adverse weather
during the hatching stage.
In contrast I have had many happy
adventures in the Sandveld this year and seen an incredible breeding success
story there – of the 17 pairs monitored 13 fledged a young.
I’ve put together some data
below, which Lucia Rodrigues and Cape Nature have also made contributions to.
Overall the most surprising result for me has been the much higher successful
breeding attempts in the Sandveld compared to the Cederberg. However, don’t
take this on face value – the eagles occur more densely and with more inter-pair
competition in the ‘berg. So perhaps if we represented the data as successful
breeding per km2 we’d see a slightly different story.
Figure 1: Breeding outcome of
Black eagles from 2010-2012 (n=83) based on 39 nest sites.
So as this season closes I wanted
to say a big thanks for all of your support, interest and encouragement –
Special thanks to Quinton & Liz (Cape Leopard Trust), Driehoek Wine, K-Way,
David & Cisca (Cederberg Cellars), Kevin (Darling Brew), Les Underhill
& Andrew Jenkins (ADU), Cape Nature, Dickon (Evosat), Victor (Spanish Ministry of
Environment), Hank, Alan, Marcus, Anzio (Eagle Encounters), Tom & Tessy
(the Vlei), Patrick, Karen & Pierre (Waganpad), Tilia & Lawrence
(Donkieskraal), Louise & Gary (Leipoldtville) and everyone I’ve met on the
road!
See you all next season!
Comments
Post a Comment