Sunday, 6 September 2015

Observations on Eleonora's Falcons in autumn

The world population of Eleonora's Falcon breeds almost exclusively around the Mediterranean and is estimated at around 20,000 individuals. It's a long distance migrant, wintering in Madagascar and neighbouring East Africa.
First recorded in Britain in 1977 there have been a handful of records since.
In common with many birdwatchers I have seen Eleonora's Falcons many times in spring and early autumn in the Balearics and Greek islands but have only seen birds in juvenile plumage twice; once in Israel in November and Rhodes in late October.

Juvenile
Photo 1 Eleonora's Falcon juvenile Rhodes October
Photo 2 Eleonora's Falcon juvenile Rhodes October
Juvenile Eleonora's falcon is noticeably shorter in the tail and wings than adult birds, at least in early autumn, when birds have recently fledged. The profile is closer therefore to male Peregrine but should not cause confusion for anyone reasonably familiar with that species.
Photo 3 Peregrine recently fledged juvenile June (© K Smith)
Photo 4 Peregrine 1 cy April

Eleonora's is still a significantly slimmer longer winged and tailed falcon. If any doubt remains the dark underwing coverts contrast with the pale base to the remiges whereas juvenile Peregrine (Photo 3 and 4) has a very uniform underwing at this age. 
This pale wing flash may also be visible on the upper wing on some birds. Peregrine also has barred undertail coverts which are plan in Eleonora's.
Size is intermediate between Hobby and Peregrine and Eleonora's is noticeably larger than both Hobby and Red-footed Falcon. The pattern of the underwing described above with broad dark trailing edge to the wing should help to separate from the two smaller falcons when size is difficult to judge. 
In addition Eleonora's has a single moustachial streak, lacking the second streak below the ear coverts shown by both juvenile Hobby and Red-footed Falcons.
The eye ring is blue or bluish grey in Eleonora's whereas Hobby and Red-footed Falcon have yellow eye rings. The eye ring of juvenile Peregrine is greenish blue but turns yellow within a few weeks of fledging.

Adult - pale morph
Photo 5 Eleonora's Falcon adult female Rhodes October
Photo 6 Eleonora's Falcon adult male Rhodes October
Eleonora's Falcons can be aged in their second calendar year and sometimes in the third by examination of the extent of moult and feather wear. 
The birds in Photos 4 and 5 are both pale morph adults. The female in Photo 4 was noticeably larger than the male and looked a generally heavier bird. Adults can be sexed by the colour of the orbital ring and cere, this is blue in females and yellow in males.
The combination of blackish underwing coverts and plain slightly paler remiges with heavily dark streaked buff underparts turning orangey on the belayed inertial coverts should rule out any other European falcon.
Behaviour
Although the literature reports that migrant passerines are a key food in the autumn, of the dozen or so birds I observed any hunting was for aerial insects Some birds were observed hawking for insects for the whole time they were in view. Eleonora's is a very agile and graceful hunter and looked to have a high success rate using the feet to grab the insects.
Photo 6 Eleonora's Falcon male catching insects

3 comments:

  1. Dear Trevor
    I am based in Pretoria and am the author of the Raptor Guide of Southern Africa. I am currently preparing the book to be reprinted and like to use this opportunity to make some improvements. This is the reason for my email: I would very much like to, if at all possible, include your photo 2 above of the juvenile Eleonora's Falcon in the reprint. If you would consider this, please contact me on ulrich@ulrich.co.za. Kind regards
    Ulrich Oberprieler

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    Replies
    1. Sorry Andy. This is addressed to you - not Trevor. Regards Ulrich

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    2. Hi Andy. Thank you very, very much for the image emailed. This is greatly appreciated. My emailed answer bounced back, thus I am using this message system again. Thank you for your kindness and good luck with your myriad of activities - your blogs are quite amazing. Regards. Ulrich Oberprieler

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