At a recent field site in Bellevue, one of my regular visitors was the most fantastically leucistic crow I had ever seen. Naturally, I dubbed him or her “ZB” for Zebra Bird. One or two white feathers is pretty common but this was something far more spectacular. Something that, to the naive observer, may look like a whole different species of bird. In response, I thought it might be helpful to talk about how and why crows have white feathers or other kinds of color aberrations. First off, let’s put some definitions on the table since there are a few terms that often get mixed up, or have different definitions depending on your source. The following definitions are based on those provided by Guay et al. 2012.
Albinism results from a complete lack of melanin in both the feathers and all the soft body tissues. This causes red eyes and pink legs, making it very easy to spot. Albinism is often associated with poor vision and hyper-activity which quickly removes it from the general population and why, when it is spotted, it’s usually only in young or captive birds.
Leucism is a complete lack of melanin in all or part of the plumage, but not necessarily the soft tissues. It is sometimes referred to as ‘partial albanism’ but if you’re familiar with the definition of albanism (which hopefully you are now!) you know the term ‘partial albinism’ is oxymoronic. Leusistic birds can have one or multiple white feathers, as is the case with my friend in Bellevue, or be completely white but with regularly colored eyes. Their feet and bills may or may not appear pink like that of an albino bird’s.
Schizochrosim is a lack of a particular pigment. So a bird lacking the phaeomelanin (brown) pigment, for example, would appear grey.
Melanism is exceptionally high deposits of melanin that make the animal appear darker overall.
Carotenism is a change in the amount, distribution or composition of caroteniod (red, yellow, orange) pigments.
Dilution is, as the name suggests, a muting of colors across all or part of a bird’s plumage.
How do these color abnormalities arise? There are a couple of different pathways including genetics, diet and injury/disease.
Albinism is genetic, specifically, it’s linked to a recessive autosomal gene. If you’re reading this and thinking “autosomal recesisve…what?” remember that humans have 23 pairs of chromosomes. Twenty two of them are autosomal and the last pair are sex chromosomes (you’re either XX or XY, sound familiar?). Recessive means you need two copies of the gene to express the trait. What this mutation does is cause an absence of the enzyme tyrosinase, which is used by the body to create some of the colored pigments. Because albinism is heritable, it can be bred into an artificial population by a skilled breeder, which is why you may see things like white tigers and lions in the entertainment business. Despite their dramatic color variation from their peers, they are not distinct species-an idea I occasionally see being perpetuated on social media. Genetics also plays a role in leucism, though it’s often only part of a more complicated mechanism.
Diets low in protein may also contribute to leucism, as the amino acid lysine has been correlated with increased white feathers. This is supported by the observation that urban birds (who presumably have a diet lower in meat and protein) typically have more color aberrations than their rural or forested peers. Carotenism, on the other hand, is very strongly influenced by diet, since animals cannot produce this color on their own. A very familiar example of this is seeing the white young of flamingos who, in this early stage of life, have not yet had enough time to begin producing mass quantities of their pink pigments.
Lastly, age and injury may also contribute to feathers which fail to correctly pigment though this is poorly understood. Somatic genetic mutation (i.e mutations that occur after conception) are associated with increased age, and indeed, older crows are more often seen with white feathers. Avian Pox is known to play a role in carotenism though not much is understood about this.
*Updates* a previous version of this post contained a typo stating that humans have 24 pairs of chromosomes.
A previous version stated incorrectly that a complete leucitic juvenile could be identified by its correctly colored iris. Since blue pigments occur irrelevant of melanin, this is not the case.
Guay, P.J., Potvin, D.A., and Robinson, R.W. 2012. Abberations in plumage coloration in birds. Australian Field Ornithology 29 23-30.
66 responses to “Crow curiosities: what causes white feathers?”
Hi Kaeli – has the observation that urban birds are more often leucistic ever been properly studied? Is there any published literature on the frequency of leucism in urban versus rural corvids?
Have just found your site and am enjoying reading about your research Reminds me that I have a short blog post about crows that I want to put up at some point soon.
All the best,
Jeff, the short answer to your question is no, there have not been any systematic surveys done of rural vs urban birds across multiple species-which is what I suspect you meant when you asked if it have been properly studied. There are however, a number of papers which looked at leucisim that mention surveying for a particular species in both urban and rural areas and only finding leucistic birds in the urban areas. This is usually mentioned as an aside in the methods, however, since quantifying the difference between then two areas wasn’t the focus of the papers. It’s a good question though and something that could make a worthwhile citizen science study for sure!
You read my mind! Yes, it would make a great citizen science project. Would also be a useful system for tracking individual birds between sites to see how, for example, they move between and use urban parks, because the pattern of white feathers is often very distinctive.
We saw a brown and white crow in north hill. .is this common?
Hi Susan, thanks for your question. The brown feathers likely indicate that this is a young bird, as the first year flight feathers are less heavily pigmented and thus often appear brown in contrast to adult birds. As for the white, we also see a fair amount of those especially in the urban core. So while it might be a stretch to say it’s common, it’s fair to say it’s not uncommon if that makes sense 🙂
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Looking For a white crow or White Crow feathers to use for Snow Crow’s new CD http://www.snowcrow.com read our Philosophy to know more about us.
Can anybody help us out here??? w white crow feathers to make a mandala with or a white crow we could take a picture of the Band with.
Hi Daniel, what a great concept for a band! I love it. I don’t know how helpful my two cents will be, but I’ll offer them to you anyway. As far as the feathers are concerned I won’t weigh in on that other than to provide the gentle reminder that possession of such objects are violations of the Migratory Bird Treaty Act (under which crows are protected) and punishable by law.
As for locating a whole, living white crow you could take pictures with my best advice would be to start checking in with local wildlife or birding message boards. Those are often the first places sightings of an unusual individual will pop up. You could also try local wildlife rehab facilities which may receive such an individual in need of care, or may know of someone who has a permit to keep one for public outreach.
Lastly, if you’re not too worried about your audience taking issue with a biologically inaccurate photo, you could look into whether or not the small populations of white ravens continue to make Qualicum Beach in BC their home. There was a group of three living there in 2010 but I haven’t seen much since then. Good luck and hopefully other commenters will have some additional insights!
Would also be worth posing the question on one of the Facebook birding sites; there’s lots of keen photographers on those.
Thanks good idea, Have some birding friends etc. will follow up in that direction as well.
Thanks so much, for the direction etc. will continue to search around. I have an artist friends (www.briankeeler.com) who I know could do a great painting, check out some of his allegorical paintings. Graphically could always take a picture of a crows feather and replicate via photo shop, filling in the black w white. At the beginning of the album’s (yes expecting to release a limited # on vinyl) so we have time and options for graphic size.
The graphic on the web site (from our first CD) is appealing as is, but time for the next step. Thanks Dan and Snow Crow
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Can anybody help with a problem i have ?
we rescued a baby crow and he/she was doing well until last week we ended up with lots of feather loss on the head and a weezing coming form the air intake ?
Michele, please take the crow to a licensed wildlife rehabilitator. It is illegal to possess this animal without proper training and licenses.
I just wanted to say that I didn’t realise there were white crows in the world til last weekend, when I spotted one in Clitheroe, Lancashire, UK at the weekend. It was totally white….and I got a photo but only on my phone so the quality isn’t great. Then a workmate pointed me in the direction of your blog. Very interesting than you.
Thank you….not “than you”!
I’ve wondered how often it happens that people see leucitic birds and mistake them for new species. Seems like it would happen a lot! Glad your colleague was able to help you out, and thank you for the compliments
On tonight’s ephisode of Animal 999 (12/08) they put a crow to sleep because it had “white feather disease” is this something different?
I have never heard of such a thing and cannot find any resources about it. The only thing I was able to find that might fit the description was psittacine beak and feather disease, whose symptoms can include white, streaky feathers. But, as the name implies, this is only a problem for psittacine species (i.e parrots). I am stumped to explain what this “disease” is or why they put the animal down because of it. Any Scottish vets out there that can offer an explanation?
I have just seen this programme; the vets (in Scotland) said they had to break the run of the genetic disease so that this crow did not pass it on – white or part white crows can suffer attacks by non affected crows?
Hello. Thanks for the info. I found one that was Leusistic last week. Luckily I had my good camera with. I spent an hour just watching, photographing and a short video (I tried one before the one I got and was having problems). If you’d like to see the pictures let me know. I had a long lens and some are pretty good quality but I don’t think I can put them here.
Sure Steve! You can send them to email@example.com
Hi, found this while looking for explanation for a pair of these I saw earlier in the week in our local ‘castle’ museum park (Cliffe Castle, Keighley). Helpful museum lady said they’d been there all summer. Sibs? One of them has almost-magpie-like wing markings. Would you like photos of these as well in addition to the ones mentioned in previous post? Got a couple of not-very-good shots of one of the pair when I went back with my real camera, but hope to get more because they’re stunning.
Sure Jane! If you get some good ones send them to firstname.lastname@example.org.
Have you even seen ravens with white patches?
Not in person, but they’re certainly out there!
We have a crow’s nest next door in a very high gumtree. It has been there for a few years now and the crows are breeding well. I haven’t noticed until recently that some of the crows have white feathers under their tail feathers as well as a few under their wings. I came onto this site because I was sure that crows were all black but your site has answered my question. We also have magpies breeding in our area but haven’t sited their nest. I had been thinking that the crows and magpies may have interbred. Is this at all possible?
I live in Australia only 7km from the city so very lucky to have abundant wild life to observe.
Hi Selena, I was very confused at first when you mentioned the crows were actively breeding but then you clarified that you’re in Australia and now I feel like I have my bearings 🙂 As for your question, the short answer is no, not really. Although the idea of ‘species’ can be a little wishy washy, and we know hybridization happens across lots of different groups, your case would be especially remarkable because crows and Australian magpies are not even in the same family, let a lone species. Australian magpies are actually Artimids (butcherbirds), not corvids (which maybe you already knew). Any mating that might happen between then would therefore defy most of what we understand about animals in terms of mate selection. Does that help?
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I rescued a baby crow last year who was I would say half black and half white. She had lots of white wing feathers and no tail feathers. She could not fly at all. After ringing rescue centers and getting no response I took her to the vets for them to check her over. The vet kindly explained what and how to feed her. I still have her and all the white feathers she had have gone and in place she has those lovely blue black feathers. Before anyone says anything I have gone down the right channels to have her and she is registered. I would not recommend keeping wild birds and she is hard work but she is part of our family and still can not fly and has imprinted so she could not go into the wild. The point I’m making is these birds and certainly mine can obviously lose the white feathers given the correct diet as my crow has done just that.
hello, we saw today a crow with white feathers, here is the link to the photos
In the last few months I have noticed jackdaws with several white feathers dotted all over there body really quite pronounced
I live in Lytham Lancashire England
The “Daurian” jackdaws have extensive white markings.
Correct. This post was addressing the presence of white feathers in species where that is atypical. But there are serval Corvus and corvid species that have naturally white feathers.
Does anyone study their language? I have managed to figure some things out on my own with my same group over past fifteen years. But is there a scientist who knows how many “Caws” mean what, the spacing The up and down tones? I have a few nailed down. Five crow caws means food lies here, come now! Cooing sounds are they are actually interested in the cial treat you have and are begging for it. Two sharp rapid caws means trouble danger stranger alert. Three caws means coast is clear can swoop down and eat, also a call defining you the human as friend not foe! That is all I have now.
My colleague, Loma Pendergraft does! You can find his website and contact info here https://clevercrows.wordpress.com
I live in ohio and the crows around my work have white at the tips of their wings. Some more than others. This one baby in particular head looks almost grey. As if he is almosy losing his feathers? Or possibly has some sort of mange? Trying to figure out if its serious or not and if mayb i can help w their diet of whatever is missing.
the white feather tips aren’t anything to worry about. As for the baby, when you say “almost as if it is losing its feathers” is it actually? If so, that’s usually mites or attacks from other birds. Either way I’m afraid there’s not much you can do
Hi, I live in the East Midlands, a small crow was being picked on and attacked by 2 bigger ones and I went to scare themail off…..ever since the crow has been in our tree and garden …he is growing but has some white feathers on his breastfeeding and can’t seem to fly, he comes down for sausages and other food daily. What can we do to help him?? ….I say him because I have called him Russell!!thanks 😊
Hi Roz. When you say it’s been growing…how long have you been watching it? I’m surprised that a difference in size would be detectable to you unless this was a very, very young crow. But judging by the time of year that’s improbable. Is it still unable to fly?
One of the regular attendees of my feeding sessions a couple years back was an equally-striking crow that I named Mr. Fingers. He was really sharp, even in comparison to the others that were regulars (“Half Beak”, “Bad (or Fat) Manners”, and “Basketball Jones”, to name a few of my most favorite). When others would shy away, Mr. Fingers would walk up to me and stand right alongside, about 18″ from my boot as I tossed full peanuts out. Being a Dr. Smartbird, he realized I didn’t pose a threat and that being so close afforded him the chance to keep all the peanuts that would get away from me to himself.
He was also the first in my group to realize that he could shell the peanuts then and there, allowing him to stuff far more of the goods in his craw than the 3 full peanuts that seemed to be all anyone else could manage to retain. Others started to adopt the practice, and it’s now become part of their status crow.
He ended up having an offspring with the same patterning (“Son of Fingerstein”), and they seemed to be doing well when I last saw them. Unfortunately, I’ve not seen either of them in my area (Queen Anne/Fremont) for a couple years. Last year, however, I did see a pair with very similar markings swoop overhead as I was driving South on 3rd Ave near Edmonds Community College (if memory serves — maybe a little closer to Lynnwood). I like to think that the two of them are still birdin’ around up north, trying to beat the rat race of living in the city, and decided to say hi when they saw me in their neck of the woods.
Are you familiar with banded quail (Philortyx fasciatus)? I have seen a photo of one with white feathers on its backside and wonder if that means it is old or is it just a mutation?
Not specifically, but I looked up some photos and did some googling into weather you can age them by plumage and I can’t find any evidence of that. So assuming it’s just a leucistic individuals.
Really appreciate your feedback. You don’t think it has anything to do with it being really old then?
no, I very much doubt it.
I enjoyed your article very much, was very informative and insightful. I love corvids of all kinds and find them fascinating! Recently I dreamt of having a mottled, or leucistic crow in my back yard. He was very docile and I was able to hold and pet it. He had an unknown injury and was grateful for my care. He snuggled close to me while I held him. Naturally this was a dream, but a rather interesting one. I just wondered if such an event could actually occur?
Young crows will imprint on people and can be very affectionate (like parrots). Not a behavior to encourage, however.
I just found my little white winged crow dead. I could tell over the past week something was not right. No signs of the pox, even though I’ve seen a couple in the flock with it. Not sure what to do with the corpse, since this is a rare bird and have only befriended one other in my life. Any advice? Beautiful unique feathers.
Hi Andy! Was it near a power line? That is a common source of mortality and doesn’t leave much evidence. As for what to do with it, I would really like it. But outside of the unlikely event you want to drive it up to Seattle, I bet your local Audubon Society would appreciate it!
Your blog didn’t allow me to post a response to your comment and I tried to send you an email. Neither seemed to work. So here is with a HUGE surprise at the end.
No power lines. It died from a broken neck. It either fell from the maple tree head first onto a concrete patio or was chased by my local two young sibling Copper’s hawks into the side of a home. I couldn’t find the impact point, so I’m guessing died in sleep and fell. But in the days leading up, I could tell something was off. Drinking more water, more standing still watching things and easier to get close to. I’ve had several crows in this state of mind even spend time next to my big black and white Persian who could care less. Boris has had the hawk standing right next to him before, side by side, and he doesn’t care. There were zero signs of the pox, which I know well after documenting a couple dozens deaths over the decade. I do think someone is poisoning the crows, maybe not on purpose (you never know until you know). This year, I had three of my crows die in a matter of 12 hours. The third death was violent and disturbing to watch. I tried notifying the Portland Audubon Society about the deaths, but they never seemed that interested.
I did preserve the wings in a salt solution, since they are so rare. Not sure how well they will come out, since this is my first time. Wednesday will be 2 weeks, so I’ll clean them and try and open the wings and feathers fully. The bird had the strangest feathers I have ever seen on the back of the neck. It’s hard to describe, but the pictures are stunning. The head was not so attractive, almost grayish. You could tell the bird was going through a molting stage, but these feathers were really strange. There were black tipped mohawk of feathers on the back of the neck, but only the tips were black, while the rest of the feather was in a white sheath. Much of the base feathers under the body exterior feathers were very light in color too. I’ve not plucked any feathers since I already felt terrible about the wing removal. I did bag up every loose feather I could find.
So here’s the exciting part. A week later, just a week ago, another crow showed up with white wings. The wings reminded me of a WWII plane that had a country identifier on the top and bottom of the wing, but in just white. I managed to get some video of that one and I need to review my security camera to see if I have any hidden gems.
So what could be more exciting than that? Another white winged crow. The white isn’t as brilliant, but it’s every bit as beautiful and has markings on the tail feathers. Even though it looks similar to the one I filmed last year, that one did not had a band of white all across it’s tail feathers. How rare is it to see four white winged crows in a year?
Hi Andy! Ok couple things to cover here so I’m just going to check them off. 1) the symptoms you’re describing sound like West Nile virus. You may see if ODFW is interested. 2) the strange feathers you describe are the new ones growing in during the molt. 3) I have to remind you that keeping crow feathers/body parts without a collections or hunting permit is technically illegal. 4) how cool another showed up! I’d say seeing 4 in one year is pretty rare. I usually only see a couple.
I photographed a Leucism Crow yesterday at Sale Water Park in Trafford (Manchester) in the car park.
Bright white symetrical plummage in the wing and tail feathers. A very tame bird allowing my to photograph it close up. Beautiful bird.
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I was just reading this blog and not realizing that I was also listening to you on Ologies! I had such a similar experience to you in school (and my career, I found out about my ADHD much later in life!) so I feel very seen listening to you!
I think I saw a Leucistic crow the other day at the Ballard locks. The bird flew right up and sat next to me, so I got a good look, but I have a potato for a camera so I didn’t get a great picture. I initially thought the bird was just sooty but upon closer inspection, it was flecked brown and white and was super pretty 🙂 Is anyone doing any research on population/sightings that need a data point?
Not that I know of, but your welcome to share to the Corvid Research Facebook page!
There are lots of “zebra” colored crows around Seatac’s Botanical Garden.
Hello Kaeli- 2 year ago we noticed a lot of Crow action off our deck in Mill Valley, CA and saw that they were attacking a Raven non-stop and he came to rest on our deck-railing and I noticed his whole breast was bare of feathers and looked like chain-mail from neck to waist- he was limping a bit also- I felt bad for him and called Wild Care- a rescue center for all animals and birds in Marin County. The person I spoke with asked me if he could fly and if he could he was probably alright- she didn’t know what the bare area was about and that if he couldn’t fly that I could bring him in.
I was conflicted about giving him any food but he looked in terrible shape , so I gave him some of our egg-breakfast- he couldn’t get enough of the yolk!! and would come back a few days later. It got to where I could feed him by hand, and we named him Munin after Odins ravens. After a couple of months he came by with a female and it seemed like he was trying to show her what a good provider he was. All this time I was conflicted because he’s a wild animal and is it okay to feed him?? But then people have bird feeders and also toss out birdseed, but if you saw him- he looked Ancient and beat-up- so I continued to feed him- it was incredible the way he would try to be the only one to eat but would then feed her- we would sit at the table in the morning and if we weren’t quick enough they would jump down on the deck and peck at the glass door for their snack- theres a lot more to the story but I wanted to be able to talk to Corvid expert because I’m planning to write about my Raven experience. I got your name from Nick Mason back in Louisiana and would love to be able to talk with you, thank you- I love your site!!!
Hi Rand! As long as you maintain some boundaries (I wouldn’t continue the hand feeding) you’re alright. They won’t get dependent. Amazing to have a raven friend!
I have spotted a black and white jackdaw on the field at the back of our house,I will attempt to get a photo of it if I see it again
Hi, I’m a wildlife rehabilitator and we get crows from time to time with some white feathering. Sometimes it’s one of the conditions you mentioned, but there are health issues (typically nutritional during crucial development stages) that can cause this as well. If and when we are able to resolve the issue, normal, stronger black feathers grow back during the next molt. Here is an article containing links to a few studies you might find interesting. https://morgithology.blogspot.com/2010/12/feather-de-pigmentation-in-carrion-crow.html?m=1
I had to search the internet for information on this topic because this morning I had a crown in my back yard that was almost half white. I took a video although he was quite far away you can clearly see his white feathers.
Hello, I have befriended the crows in a local park and could call them in for feeding. One, my favorite, had quite a few white feathers. After the molt this year, it has seemed to disappear. Maybe it left the area or died. My question is can these birds change color. Perhaps losing the white feathers and becoming entirely black. I’m hoping it’s still alive.
Hi Penni, yes there are cases where they simply molt them out. So it’s possible your bird is now blending in with the crowd
The crow you call ZB looks like one I had in Tacoma, Washington around 1995. I named it ,”Shadows Dancing”. It was black all over, but lifted wings showed a total white under the wings.
Hi, been noticing crows with black and white feathers recently at a lake next to a restraunt in Llanelli, south Wales, never seen these in my life before, very beautiful. They’re definitely crows, mingle among groups of other crows walking about, so guessed they’re a generic variant, but yeah perhaps it’s lack of nutrients and aging, as I’ve noticed they do all look quite rough, as in elderly. They’re mostly black outwardly with little white giving themselves away, though once they take flight, they reveal the under wing and tail which are absolutely beautiful, seems every other feather is white like piano keys. Noticed some swans at the same lake have grey bills instead of orange, I’m guessing they’re elderly. Hope these gorgeous crows aren’t suffering, will be keeping an eye out for more, no-one else knows what I’m on about when I point them out on our walks. Thankyou and take care.