Showing posts with label Ardea alba. Show all posts
Showing posts with label Ardea alba. Show all posts

Wednesday, 1 March 2017

Great Blue Heron x Great Egret

Great Blue Heron x Great Egret hybrid, Fort de Soto Park, Pinellas County (Florida, USA), 17th August 2016 - copyright Dave Norgate
(photo ID: 2976)


The long kinked neck of this intriguing bird is very much like that of a Great Egret, but in other respects the structure of this bird seems to resemble Great Blue Heron as much.  The grey plumage and the bill do not belong on a Great Egret, whereas the yellow lores must come from an Egret species.  The latter, along with the neck structure, help rule out Würdemann's Heron (the hybrid or intergrade between Great White Heron (the white form occidentalis of Great Blue Heron that occurs in southernmost Florida) and typical Great Blue Heron.

Thanks to Steve Mlodinow for pointing out that this bird has been accepted as this hybrid by eBird reviewers and photographed by other observers over six months.










Great Blue Heron x Great Egret hybrid (same bird as in photo ID 2976 above), Fort de Soto Park, Pinellas County (Florida, USA), 17th August 2016 - copyright Dave Norgate
(photo IDs: 2977-2986)



Great Blue Heron Ardea herodias
Great Egret Ardea alba

Great Egret x Snowy Egret

Great Egret x Snowy Egret hybrid, Fort de Soto Park, Pinellas County (Florida, USA), 18th August 2016 - copyright Dave Norgate
(photo ID: 2987)


Dave says this bird seemed intermediate in size between Great Egret and Snowy Egret.  Structurally it seems to have an intermediate neck length and shape - you can see a hint of the kinked shape of Great Egret in some of the photos but it's not as clear as in a pure bird.  The bare parts also seem to be consistent with expectations for this hybrid.  Certainly the legs are wrong for Snowy Egret being entirely black right down to the bottom of the feet.  The gape line only extends back to below the cetnre of the eye, just like it does on Snowy Egret.  On Great Egret it would extend right back to beyond the back of the eye.  The only pure species I could possibly turn this into is Intermediate Egret, which in some respects it quite closely resembles.  However, although the Asian form of Intermediate Egret apparently does adopt a black bill in breeding condition (I don't believe the African form does) this bird is showing no sign of being in breeding condition.  I don't think the bill structure is quite right for Intermediate Egret either, and of course an Asian Intermediate Egret is rather unlikely in Florida - there are one or two ABA-area records but only from the Aleutian Islands in western Alaska so far as I know.




Great Egret x Snowy Egret hybrid (same bird as in photo ID 2987 above), Fort de Soto Park, Pinellas County (Florida, USA), 18th August 2016 - copyright Dave Norgate
(photo IDs: 2988-2991)



Great Egret Ardea alba
Snowy Egret Egretta thula