yikes! bald birds

Ah, it's that time of year when I receive phone calls and emails from people who are profoundly disturbed -- or at least made intensely curious -- by the sight of bald birds.  Invariably, these are Northern Cardinals (Cardinalis cardinalis), with Blue Jays (Cyanocitta cristata) and Common Grackles (Quiscalus quiscula) also frequent victims of this very unflattering pattern of feather loss.

What is wrong with these bald birds?

Nothing, really.  All birds replace all of their feathers at least once a year. In temperate North America, late summer and early fall is a time when most birds are undergoing some degree of molt.  Nearly always, birds replace their feathers over a period of several weeks. But some individuals lose all the feathers on their head at the same time, creating a temporary vulturine look.  The skin is dark-colored, and so are incoming pin feathers, just emerging on the Blue Jay below, accounting for a black bristly appearance.

Feather mites are frequently blamed for this condition. I have closely examined bald birds I have caught and have never found any evidence of mites or lice; other bird banders report similar experiences. Further, most feather mites are scavengers that feed on bits of skin and feathers, oils, and feather fungi.  They don't cause feather loss, and it would be unlikely that they would cause so much discomfort that the bird would scratch out all the feathers at the same time -- and the uniformity of the regrowing feather shafts indicate that all feathers were dropped pretty much in synchrony.

Burrowing skin or quill mites are a possibility, since they would not be visible. However, according to an addendum on the Hilton Pond web site, these types of mites have never been collected on bald birds.  There is no good explanation as to why they would occur only on a bird's head and not elsewhere on the body, since they cannot be easily preened off in any location.  This summary on the adverse effects of various feather mites provides little evidence that mites can cause total loss of head feathers in birds. I scoured the literature and was unable to find any documentation that would indicate quill mites (Syringophilidae) would cause this condition, especially on a regular basis, or even that they had been recorded on cardinals or jays.

I'm not an expert on the seasonality of ectoparasites, although I have found them spring through fall on birds I've caught, but it seems coincidental that this damage would occur at the same time birds are going through a normal molting period. In fact, the common feather mites of the family Proctophyllodidae are known to move to wing and tail feathers (where most typically reside anyway), away from the body in warm weather, such as is experienced in late summer when this phenomena usually occurs. Occasionally, bald birds are seen at other times of the year, and the causes of their plumage loss may be different. 

My investigation and experience has led me to conclude that if ectoparasites are involved in this dramatic loss of head feathers, they are only bit players (heh-heh) or just happen to be at the scene of the crime. It is true, though, that many bird ectoparasites are just not well-studied enough to draw hard and fast conclusions about the role they play in baldness. No doubt, the cause probably varies between birds. One last bit of evidence that simultaneous feather droppage is "normal" in at least some individuals: there is an account by Laura Erickson of a Blue Jay kept in captivity that always lost all it's head feathers at once, every year -- for 8 years.

For the most part, being bald is not harmful to birds, except perhaps in cold or wet weather, or if mosquitoes are a real problem. Rest assured that within a few weeks, the feathers will grow back.

For more radical photos of bald birds and a rehash of this issue, see the Cornell web site. The photo of the sorry bald cardinal here comes courtesy of Shari DeAngelo via her blog Dreams, Rants and Raves; more of Shari's photos at Flickr. The pathetic-looking Blue Jay was photographed by Haggis. I had to include this sketch by Catherine Clark, who made this bald cardinal look good.

Comments

[Rurality]

So glad you posted this! People ask me the same thing, but I'd been told "mites" and repeated it.

[Pamela]

Yikes indeed! And timely, I had a search hit my blog yesterday looking for this information (and, sadly, not finding it there). I've never seen really bald birds, though this time of year I do have trouble at times sorting out fledglings from scruffy molting parents.

[Casey]

While some baldness may be attributed to molt there is also the possibility that this condition may be due to a fungus that causes ringworm. It's pretty contagious in birds and can be transmitted from bird-to-bird or through contact with a contaminated surface (like a bird-feeder).

You can learn more about this group of fungi in chapter 15 of the Field Manual of Wildlife Diseases:

http://www.nwhc.usgs.gov/publications/field_manual/index.jsp

You can also view a photo of a bald loon in that chapter as well.

Hope this helps,

Casey Tucker
Education Specialist
Audubon At Home
Audubon Ohio

[Nuthatch]

I looked into this a little. This fungus would have some effect on the appearance of the skin -- thickened or crusty -- which is usually not present in these bald birds. I was not able to find any reason why this condition would be restricted only to the head; indeed, in the photo of the loon it extends to the neck and upper body. One important reason I discounted this as a likely cause is that it is so highly contagious. You'd expect then to see groups of bald birds, and probably see them when they are most gregarious, especially at feeders in winter. Instead, this is most often reported when birds are frequently secretive, during their post-breeding molt. This might be a factor in the occasional birds seen with bald spots at other times of the year, though.

[Norene]

i've never seen a bald bird in person. whatever the cause, i think bald birds are kind of cute.

[Shelley Batts]

My African Grey, Pepper, is bald sometimes. But, he has the bad habit of chewing his feathers, causing bald spots on his chest and wings. :(

[UrsulaV]

We always call 'em the "Kojak Cardinals."

[Kay]

Thanks for this article. We used to see this at our feeders in Maryland and were very concerned about the affected birds. It's reassuring to know that it's just nature running its course.

[pixie]

Hello,

It seems that a female cardinal that frequents my birdbath is going through a balding phase, but:
1. It is April (I am in Oklahoma, if this makes a difference)
and
2. She is only bald on top, as though someone only plucked off her crest.

Any ideas or comments?

Fascinating article, btw.

[Nuthatch]

It's not uncommon for birds to lose the feathers on top of their heads if they've crashed into a window.