Posted by Buck Ward on August 14, 2010 at 10:33 PM
I occasionally see a dark morph reddish egret with some white feathers in its wings and/or tail. This one has more than I've seen in others. Does any one know if these are permanent, so that they could be used to identify individual birds? Is this an intergrade between a white morph and a dark morph?
Very weird! I have never seen anything like this..looking forward to a response from some wise person..
Sandy r
Posted by Drew Fulton on August 15, 2010 at 8:46 AM
Buck,
I have seen this too and it isn't very common. Some years ago, I talked with the late Rich Paul, an expert who spent many years monitoring wading bird rookeries in the Tampa Bay Area and he didn't have a solid explanation either. He had seen it a few times but not often. As far as I remember, it only occurs in the primary feathers and maybe the rectricies (tail). His hypothesis was that these are young birds and probably in their first year. He thought that after their first major molt they would lose these feathers and resemble a more traditional egret. As I said, it has been quite a while since I had this conversation so I may not be remembering it exactly correct. However, I do remember he felt strongly that it was not some sort of intermediate morph.
Cool birds though!
Posted by Jim DeWitt on August 16, 2010 at 12:17 AM
BNA describes these individuals as "pied."
Some dark individuals “pied,” possessing a few white feathers, often in symmetrical pattern.
I photographed a reddish with 1 or 2 white feathers, fishing in the ocean at Cocoa Beach last year. It is possible that he was a first year. He had avian pox or a similar looking malady, which gave the impression that he was older, but young birds can have those diseases too.
I found this in the Appearance section of the article on the BNA website. Richard T. Paul is co-author.
"The following information based on Bent 1926 and Palmer 1962 . Sexes alike; 2 morphs: white and dark; also intermediates—dark individuals with patches of white plumage."
Further search found an entry by Rich Paul in the FloridaBird listserv, an excerpt of which follows:
"In Florida, white-morph Reddish Egrets comprise about 5-8% of the breeding
population (although 15-20% in the Lower Keys). I believe "pied" birds are
less common than that. They certainly do reflect interbreeding between the
morphs, though very little is understood about it. In Texas years ago, I
found that white-white pairs breed true (produce like offspring), dark-dark
pairs usually breed true but occasionally produce white-morph young, and
dark-white pairs produce young of both morphs but mostly dark. The rub is,
I did not know which breeding adults were heterozygous (=the product of
dark-white pairs). So there's an opportunity out there for a good study.
Most "pied" birds show one or more white flight feathers (primaries,
secondaries, or rectices - tail feathers), usually in a bilaterally
symmetrical pattern. But some birds reveal irregular patches of white
contour feathers, and some display a surprising amount of white on their
bodies OR flight feathers. I've never seen a fledgling, immature, or
yearling bird with "pied" plumage, only adults. And I've never seen a
white-morph adult that showed a few dark feathers. But this is a highly
variable trait, so keep your eyes peeled.
By the way, I think most or all pied birds have some white feathers around
the edge of the face and under the bill. If a bird is not flying or
extending its wings during foraging, it can be tough to see that single
stray white flight feather, but a little easier to see the feathering on the
face."
There is a reddish egret that I have observed for several years. I can identify him because he has more white around the base of his bill than is usual and he habituates at a particular location. I have seen at least one white feather in his tail but it usually is not visible. Now I will look for it the next time I see him.
Discussion
6 repliesSandy r
I have seen this too and it isn't very common. Some years ago, I talked with the late Rich Paul, an expert who spent many years monitoring wading bird rookeries in the Tampa Bay Area and he didn't have a solid explanation either. He had seen it a few times but not often. As far as I remember, it only occurs in the primary feathers and maybe the rectricies (tail). His hypothesis was that these are young birds and probably in their first year. He thought that after their first major molt they would lose these feathers and resemble a more traditional egret. As I said, it has been quite a while since I had this conversation so I may not be remembering it exactly correct. However, I do remember he felt strongly that it was not some sort of intermediate morph.
Cool birds though!
I found this in the Appearance section of the article on the BNA website. Richard T. Paul is co-author.
"The following information based on Bent 1926 and Palmer 1962 . Sexes alike; 2 morphs: white and dark; also intermediates—dark individuals with patches of white plumage."
Further search found an entry by Rich Paul in the FloridaBird listserv, an excerpt of which follows:
"In Florida, white-morph Reddish Egrets comprise about 5-8% of the breeding
population (although 15-20% in the Lower Keys). I believe "pied" birds are
less common than that. They certainly do reflect interbreeding between the
morphs, though very little is understood about it. In Texas years ago, I
found that white-white pairs breed true (produce like offspring), dark-dark
pairs usually breed true but occasionally produce white-morph young, and
dark-white pairs produce young of both morphs but mostly dark. The rub is,
I did not know which breeding adults were heterozygous (=the product of
dark-white pairs). So there's an opportunity out there for a good study.
Most "pied" birds show one or more white flight feathers (primaries,
secondaries, or rectices - tail feathers), usually in a bilaterally
symmetrical pattern. But some birds reveal irregular patches of white
contour feathers, and some display a surprising amount of white on their
bodies OR flight feathers. I've never seen a fledgling, immature, or
yearling bird with "pied" plumage, only adults. And I've never seen a
white-morph adult that showed a few dark feathers. But this is a highly
variable trait, so keep your eyes peeled.
By the way, I think most or all pied birds have some white feathers around
the edge of the face and under the bill. If a bird is not flying or
extending its wings during foraging, it can be tough to see that single
stray white flight feather, but a little easier to see the feathering on the
face."
There is a reddish egret that I have observed for several years. I can identify him because he has more white around the base of his bill than is usual and he habituates at a particular location. I have seen at least one white feather in his tail but it usually is not visible. Now I will look for it the next time I see him.