On 18 May 1987, while birding at Cape May, NJ, I came across a small group of Cattle Egrets foraging in a field. Accompanying them was the bird in the photos below. In shape and behavior it was identical to all of the other Cattle Egrets, but it’s head and neck were mostly dark grayish.
Dark Cattle Egret, Cape May, NJ, 18 May 1987. Photo copyright David Sibley.
I ruled out the possibility of a hybrid, since it looked identical to the other Cattle Egrets in every respect except color. I ruled out the possibility of staining because the feathers seemed to be in excellent condition, dry and smooth. The contours of the bird, the sheen of the feathers’ surface, the “loft” of the feathers, all appeared perfectly normal. Furthermore, it would be a very odd pattern of staining – dark on the neck, breast, and primary coverts, but white on the face and most of the wings. I was satisfied to call it a melanistic or dark morph Cattle Egret.
Over the years I’ve heard of several similar individuals. The species account in BNA mentions reports from South Africa, Florida, and Illinois (Telfair, 2006). A Google search reveals additional reports from Nigeria, India, Spain, Portugal, Morocco, Barbados, Dominica, Florida, and California (see references). Excellent photos of the Nigeria, Barbados and Dominica birds can be seen in links below.
Most often the color has been dismissed as “staining”. Apparently Cattle Egrets are sometimes stained when crude oil or other chemicals are sprayed on crops such as citrus trees in Florida, and birders there report seeing oddly colored Cattle Egrets “a few each year” (Rich Paul, pers. comm.). These birds, however, are generally stained greenish or brownish, and also look disheveled. The matted feathers create gaps in the contours of the body and cause the bird to persistently preen the dark spots. I did not see any sign of that, and concluded that gray was the natural color of these feathers.
In the case of the Dominica bird, which was seen over a period of nearly three months, the color was darkest and most extensive when first seen, and was observed to “fade” over about three months. At least some of this fading could be the result of powder down, which turns blackish feathers to gray.1
The Dominica bird and one of the Nigerian birds appear to be juveniles, but many of the others (seen in spring or summer) must be at least a year old, and the South African bird appears to be an adult.
Arguments for staining (or for melanism)
- Some feathers appear to be sticking together as if stained (but most feathers appear normal, dry and smooth)
- The underside of the feathers appears paler (but this is a common natural pattern of feathers, and difficult to confirm, and one Dominica photo shows an entirely dark gray underside of the outer primary just like the upperside)
- The feet appear to have some similar kind of grey coloration (but feet and bill could be affected by melanism just as the feathers are)
- Some feathers of the Barbados bird appear dark tipped with a pale base as if each was protected from staining by an overlapping feather which has since been molted (but many species of birds show a similar color pattern naturally, and some of the wing coverts of the Barbados bird appear to be dark with pale tips)
The staining hypothesis seems to leave two major inconsistencies.
- If this is staining, how can it account for the all-dark primaries shown by the Dominica bird? Those feathers should have been well-protected from any external source of color.
- If this is staining, why is it seen in only a few Cattle Egrets, at widely scattered locations? Why not in clusters of multiple individuals or in other species such as egrets, White Ibis, etc?
Until one of these birds can be closely-studied, ideally in the hand, the true source of these dark feathers will remain a mystery, but for now my guess is that they represent a very rare melanistic morph of Cattle Egret.
References
Kempenaers, B., K. Delhey, and A. Peters. 2007. Cosmetic Coloration in Birds: Occurrence, Function, and Evolution. The American Naturalist 169, Avian Coloration and Color Vision, pp. S145-S158 http://www.jstor.org/stable/4125308
Pyle, P, and S. N. G. Howell. 2004. Ornamental Plume development and the “Prealternate molts” of herons and egrets. The Wilson Bulletin 116:287-292. http://www.bioone.org/doi/abs/10.1676/04-012?journalCode=wils.1
Siegfried, W. R. 1971. Plumage and moult of the Cattle Egret. Ostrich suppl. 9:153-164.
Telfair II, Raymond C. 2006. Cattle Egret (Bubulcus ibis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/113
Other reports
Illinois
Peterjohn, B. G. 1987. Middlewestern prairie region (nesting season). Natl. Audubon Soc. Am. Birds 41:1440-1444. http://elibrary.unm.edu/sora/NAB/v041n05/p01411-p01495.pdf
Lake Renwick, IL. summer 1987; one bird in small breeding colony “entirely gray with normal adult leg and bill color”
California
Imperial Valley, CA, Feb 2007.
Melanistic Cattle Egret – “A dark, off-color cattle egret has been foraging on the north lawn at Imperial Valley College for the past two afternoons.”
Florida
Loxahatchee NWR, FL – http://bna.birds.cornell.edu/bna/species/113/galleries/photos/CLW_CAEG-FL_Loxahatchee-NWR (subscription required) very pale gray on body, unlike others.
South Africa
This is the darkest of the several birds photographed, presumably over the next few months this bird will fade to the smooth gray shown in other photos and will begin to replace these feathers with white ones? http://www.birdinfo.co.za/rarebirds/25_avian_colour_oddities.htm
Nigeria
two different individuals
http://www.flickr.com/photos/seth_of_rabi/2817072368/ – 31 Aug 2008 – apparently juvenile
http://www.flickr.com/photos/seth_of_rabi/3047832119/ – 21 Nov 2008
Barbados
Graeme Hall Swamp, Christ Church, Barbados, 19 September 2002
http://secrb.trinidadbirding.com/bacattleegret.html
Dominica
Aug 2009 – all blackish
discussion here http://www.birdforum.net/showthread.php?t=145867
photo here (registration required) http://www.birdforum.net/gallery/showphoto.php/photo/265831/limit/recent
3 Oct – white head and neck, paler gray body http://www.birdforum.net/gallery/showphoto.php/photo/273382/limit/recent
23 Oct – gray only on wings and tail http://www.birdforum.net/gallery/showphoto.php/photo/276539/limit/recent
same bird – note dark bill tip and dark legs
23 Oct 2009 Dominica
http://www.pbase.com/tmurray74/image/118815082
http://www.pbase.com/tmurray74/image/118815083
Spain
Herkenrath, P. 2002. Another melanistic Cattle Egret. British Birds. 95: 531 – 531.
Observation of a melanistic Cattle Egret in southern Spain on 2 May 1993.
Portugal
Scheres, W. 2002. A partly melanistic Cattle Egret Bubulcus ibis. A Rocha Portugal Observatory Report 2002 15. http://www.arocha.org/pt-en/413-DSY/version/default/part/AttachmentData/data/pt-report-2002.pdf
With black head and neck, dark gray breast, other parts normal; seen several times Aug 2002 in a rookery at A Rocha, Portugal
Morocco
June 2007
http://www.valeryschollaert.com/index.php?option=com_joomlaboard&Itemid=175&func=view&id=417&catid=2
India
Willoughby, P. J. 2001. Melanistic Cattle Egret. British Birds, 94: 390 – 391.
An observation of a grey Cattle Egret [Bubulcus ibis] at Dona Paula, Goa, India, on 19 November 1995.
- Powder down is a specially modified feather that disintegrates into a talcum-like powder. A few families of birds have powder down, which is thought to be used along with oils for feather care. [↩]
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Wonderful post, David! It reminded me of a ‘dark’ Ring-billed Gull at Metzger Marsh in Nov 2010 that may have been stained, but showed many of the traits of your egret:
http://2.bp.blogspot.com/_uyVIsoPhmnE/TPEDJVljisI/AAAAAAAADus/Vg3iamJNA8Q/s1600/RingbilledGull2413b.jpg
Other pics can be seen at:
http://jerryjourdan.blogspot.com/2010/11/metzgers-marsh-oh-26-nov-2010.html
These birds certainly keep life interesting…
Jerry
Thanks for the link Jerry. That does look very similar, and it could all be staining of some kind, although the gull seems to show a more “scruffy” and blotchy pattern than the egrets, but that’s just grasping at minutiae. It’s hard to believe there could be two different explanations for this – one for the egrets and one for this gull. It would be good to hear of any other similar cases.
Hi David, I’ve uploaded to this URL (http://bit.ly/lp09CR) another sighting of a melanistic Cattle Egret, this one from Yemen. Ornithological Society of North Yemen Newsletter 1986 2(2): 10-11. A melanistic Cattle Egret observation by S. Fairman from Yemen on 20 March 1986. It seemed to be adult, it was nest-building and had chestnut plumes, etc., tho the bill and leg colour were not as bright and striking as its neighbours in the colony.
Dear comrades
We spotted a black cattle egret at mohammadi district kheri. It is unusual phenomenon in this species, now I am not sure its natural dye or stained by human.
http://www.dudhwalive.com/2011/07/black-egret.html
Hello David; FYI I found an Ashy Cattle egret in Houston in 2007, at a landfill among lots of typical CAEGs. It was present for a few months – until the flocks broke up presumably to breed:
http://www.martinreid.com/Main%20website/CAEG01.html
Regards,
Martin
I live on the island of St. Kitts in the Eastern Caribbean. I have now twice seen an all-black cattle egret, both times near our house in Frigate Bay. I have tried to get pictures, but have not yet succeeded.
I live west of Houston, TX. Please excuse my lack of knowledge of terminology. Twenty or thirty black/gray cattle egrets fly over my house every evening this time of year, along with maybe 400 white ones. I’ve noticed it for 3 years now. Most fly with the white groups, others fly in their own groups of 3-6, and some solitary ones trail the white groups. They are definitely not the same as the bigger herons that pass by. The shape, rate of wing flapping, and flight pattern is identical to that of the white cattle egret, although they may be about 5% larger. I’ll try to get pics.
Hi Bryan, It would be extremely unusual to see that many dark Cattle Egrets. I wonder if you could be seeing a few Little Blue Herons among Snowy Egrets? Photos should sort it out, even distant snapshots, just enough to show the proportions of legs and wings.
OK thx David, I’ll try to post pics in the next few days. I haven’t seen snowy egrets (I think), but plenty of white ibis and great white egret? The ibis typically have cattle egret mixed in. I’ll photograph them directly overhead, so you can see the legs straight out. At least 800 birds last night, about 25 little dark ones.
Here’s the link, I’ll be interested to hear. http://s1262.photobucket.com/albums/ii602/bryanbb44/
Hi Bryan, Thanks for the photo link, sorry to be slow replying. I would say the dark birds are Little Blue Herons. They look a little too long-legged for Cattle Egrets, and they are entirely dark, whereas all of the dark Cattle Egrets seen to date have white wings, just dark gray blotches on the neck and body. The white birds are more challenging to identify. It’s possible that some of the white birds are immature Little Blues, but at this date they should be showing some dark adult-colored feathers, and should probably be less numerous than the adults. The proportions look good for Cattle Egret (short legs) but they seem a little larger than the Little Blue Herons. So I think the choice would be between Cattle Egret or Snowy Egret, and the main differences are leg length, foot color, and bill color.