Strange Facts You Probably Don't Know About Birds

On occasion, I am called upon to render a second opinion regarding what is considered an unusual observation, behavior or presumed medical condition by the referring veterinarian. Sometimes these oddities are quite unusual manifestations of a disease process, and on other occasions, the referring situation is simply something normal that is misunderstood or an unknown fact observed by the vet or owner. This may occur because the condition observed hasn't been previously recorded in the avian literature, but may be known by aviculturists working with the species, or it may be the result of a lack of experience with the particular species by an avian veterinarian.

Eye and Eye Area Changes

Am I confusing you? What, exactly, am I talking about? Let me give you an example, and then we'll discuss some other strange avian facts. Recently, I received a phone call from a bird owner concerning her two year old Jardine's parrot, Poicephalus gulielmi fantiensis. Her darling pet had been seen regularly by her regular avian vet since she had purchased her from a breeder as a hand-feeding baby. In the winter of her second year, the Jardine's had developed a startling change that sent them packing to the vet. The owner had noticed that the skin around the eye, called the eye ring (or periorbital area) had changed from an off-white color to a vibrant orange! The veterinarian, who was not that experienced in avian medicine, seeing the orange color, assumed that the color change might be related to liver disease. In dogs and cats (and people, too, for that matter), orange skin or gum tissue, or an orangish tinge to the whites of the eyes (sclera), is usually an indicator of liver disease and is commonly called jaundice (or scientifically, icterus).

The Jardine's was acting completely normal, being playful, eating well, had normal droppings, and normal vocalizations. Presuming a liver problem, based on the orange color, the vet ran the standard battery of tests usually performed when liver disease is suspected. However, all of the test results came back within normal limits. Unable to diagnose this problem, the vet recommended performing a liver biopsy, a surgical procedure that takes a small bite of liver tissue for examination and special stains using a microscope and the expertise of an avian pathologist.

The owner couldn't resolve this in her mind, a seemingly perfectly healthy bird with no signs of illness about to go under the knife, so prior to allowing her vet to perform surgery on her birdy child, she called us for a second opinion. As she began explaining her bird's clinical signs, she was surprised when I told her to stop right there. She was just about to get into a detailed description of the blood work, when I informed her that I had a diagnosis for her. Her bird was normal! It is perfectly natural for a sexually mature Jardine's to develop the characteristic color change to the eye ring. Because she sought a second opinion prior to allowing a veterinarian inexperienced in Jardine's parrots, she was able to avoid having her bird undergo an unnecessary surgical procedure. The color change intensifies during breeding season, and may lighten up at other times of the year.

Of course, since the clinical sign (change in color of eye ring) did not make sense when compared with the lab testing, the veterinarian may have considered performing a consultation with a more experienced avian veterinarian to discuss this case, but unfortunately, he didn't. The owner called her primary vet after our consultation and explained that the change is normal in sexually mature Jardine's. The good news is that everyone learned something from this experience, and the bird ended up no worse for the wear. There is no shame in a veterinarian with limited experience with a certain species or disease calling either another vet or even an aviculturist knowledgeable in that bird or condition.

Rose-breasted cockatoo hens undergo a maturity-related periorbital change, as well. The skin around the eyes of a sexually mature Rosie hen develops a deep pink color that has a raised, wrinkled appearance. I have had more than one frantic phone call from an owner who was very worried about the funky skin changes around their pet's eyes. Again, this change denotes the onset of sexual maturity, under normal conditions.

Some species of baby birds have a distinctive color change of the iris (the colored portion of the eyeball surrounding the pupil) that occurs as they mature. For example, baby blue and gold macaws, Ara ararauna, have a grey iris, which slowly changes to a more yellowish color as the mature. Actually, most macaws start their lives with greyish irises, which change to a yellow or brown color as they mature, during a fairly predicable time frame, depending on the species. African Grey parrot babies also begin life with grey irises, which morph into a lovely yellow color somewhere around one year of age, but the time frame is somewhat variable. Most of the Poicephalus species also begin life with greyish irises, which change to brown, red, orange or yellow, depending on the species.

Nervous Habits

Several owners of pet African Greys have asked me about a behavior they have noticed with their pets. Apparently, some Greys, when nervous, bite their toenails. I have seen this firsthand in four of my client's pets. When I first noticed Buddy, a good friend's African Grey, holding his foot up and sort of preening his toenails when I approached the cage (I am his vet and not his favorite person), I mentioned this to my friends and they regaled me with tales of how, whenever Buddy was nervous, would bite on his toenails. He didn't actually shorten his nails, but he runs his nails through his beak. I have seen and heard about this enough times that I believe that this is a peculiarity most common in Greys, but I have heard of other species of birds that chew their nails, too.

Macaws, when nervous, may be inclined to ruffle their chest feathers in waves, however, I have also seen this in Amazons. I have had owners believe that their birds were cold or chilled when ruffling, but I believe that this is just a nervous habit.


It is fairly common knowledge that adult budgerigars often regurgitate to their favorite toy, mirror or person, but what many folks may not know is that almost all species of psittacine are capable of regurgitating to their favorite person, even at a very young age. My friend and client, Jeannie Pattison (the African Queen), gave me a baby Meyer's parrot that I had wanted as a pet, and my Keely has been regurgitating (or making the motions, anyway) to me since he weaned. I have many clients who have parrots that regurgitate to them during their quiet, cuddly times together. It seems that macaws are particularly prone to offering this sign of love and affection to their owners, although Quakers, cockatoos and just about any other type of parrot may perform this behavior, which is usually reserved for the bird mate that they breed with, and for feeding their offspring. People may argue about whether or not birds can feel emotions, but I truly believe that birds do this as a sign of affection for their owners.

Head Shaking

When I acquired my first cockatiel while in vet school, I noticed that Buzzy would often shake his head while I was talking to him, especially when I was repeating a phrase that I was trying to teach him. He would seem to go into what I would call "record mode" when I was working with him, which entailed him shaking his head one time after I repeated the phrase each time. Even after he had learned to mimic a word or phrase, he would still shake his head when he heard it again. It was such a cute little behavior, with his crest doing a little jiggle each time, making me smile. Since then, I have had many cockatiel owners ask me about this same behavior, and I have always explained it in regards to a cockatiel's learning behavior.

Of course, head shaking is not always related to a bird listening to a word or phrase. It may be a sign of an ear infection, sinus infection, eye infection or even an infection of the oropharynx (mouth area), choana or crop. If the head-shaking involves the bird slinging mucus or food, then the bird should be taken immediately to an avian veterinarian for examination to determine the reason, or if the head-shaking doesn't relate to a learning session, the bird should also be examined.

I have occasionally observed this behavior in other species of birds that are listening intently to their owner, and are in record mode. But cockatiels, by far, are the most common perpetrators when it comes to performing this strange head-shaking behavior.

The Yawn Spot

Most baby birds can be made to yawn by gently massaging the areas on each side of the head, below the ears, in the areas of the temporomandibular joints. For some reason, by gently touching, or lightly making little circling motions in that area, this will elicit the yawning response. I think this response can be elicited in most species of psittacines, but I usually fool around with baby macaws and Amazons, making them yawn.

Bloody Tears

Rarely, when handling certain African Grey parrots, and Timneh Greys, they may actually secrete bloody tears! I have seen this most frequently in Greys being manually restrained for examination and diagnostic sampling. It may have something to do with nervous Greys having a dramatic rise in blood pressure, but this is not something that I have been able to fine documented in any textbooks. The majority of Greys that I have observed with bloody tears have had a chronic, active sinus infection, or upper respiratory infection, but in one or two cases, I was unable to diagnose any abnormal pathology. In those cases, I assumed that the birds had had some permanent damage to the sinuses behind the eye previously that had resolved, resulting in stress precipitating bloody tears with stress. Sometimes, I have seen these bloody tears in just one eye, but in most cases that I have seen, it has been bilateral. I would certainly say that if you or your avian vet catches up your African Grey, and you notice bloody or red-tinged tears, it should receive a work-up for a potential sinus or respiratory problem, as well as receiving a thorough ocular work-up.

The Nicotine Connection

There seems to be a higher incidence among bird owners who smoke who have problems with their birds respiratory systems and eyes (from second-hand smoke, no doubt). But another, more insidious connection has been implicated between smokers and birds having problems with itchy feet and/or feather-picking. The nicotine residue on a smoker's hands may be enough to cause absorption through the bird's skin, resulting in birds that chew on the skin of their feet, and may pick at their feathers and act itchy. The birds may develop pododermatitis, with scabs, picking at the feet, and secondary infections. Macaws may also develop a similar irritation to the facial skin following repeated contact with smoker's hands. Some feather-picking in birds will resolve when the bird is removed from the presence of cigarette smoke. It is very important for cigarette smokers to wash their hands prior to handling their birds, and birds should never be exposed to any type of smoke (legal or otherwise).

When A Bird's Owner Has A Cold

Many owners worry that their own family's colds or flu viruses will affect their pet birds. The good news is that the majority of human viruses are not contagious to birds (with the rare exception of a virus or two). However, that doesn't mean that we should allow mouth to beak contact with the birds we own, even if we are healthy, as some of the bacteria, yeasts, or other organisms found in our mouths can be dangerous to them. But I have examined many a bird that had developed a nasty cough or had sneezing fits that were actually just the bird imitating the latest cold virus that a family member was experiencing. And we think birds don't have a sense of humor! They hear their steward coughing, and secretly practice it until they have it down pat, then they begin hacking in front of the concerned owner. Not knowing that birds are not likely to catch their cold, they pack their beloved pet off to the vet for a check-up that comes up with the physical exam and test results showing a normal bird. Yep, it had learned to cough, and got a free (well, to the bird, anyway) trip to the vet!

Diet and Hardening of the Arteries

Well, it was bound to happen. We have known for quite some time now that there is often a connection between a high-fat diet in humans and hardening of the arteries and plaque formation in the vessels of the heart. And now, avian pathologists are finding that birds (especially African Grey parrots) are also showing, as incidental findings, plaques in the blood vessels of the heart. These findings are being discovered in birds that have died of other causes, and the pathologist is just noting that there are changes that have occurred in these vessels. This is just one more reason to get your pet birds off of a seed-based diet, as the high fat can certainly be contributory to blood vessel changes that could be life-threatening in time. Lesions may also be found in other areas, including the aorta (abdominal), a major vessel called the brachiocephalic trunk, and, as in humans, in the internal carotid arteries (those arteries in the neck).

It has been known for some time that older, overweight, sedentary Amazons have higher rates of atherosclerosis than other species of birds, however, finding it in African Greys (often of normal weight) on all-seed diets is, to me, alarming. If you are concerned about the problems related to atherosclerosis in your pet Grey, you may wish to discuss its diet with your avian veterinarian.


Well, you now know more about birds than you did before, and I hope that some of this may apply to a situation that you are experiencing with your bird, helping you to better understand your psittacine. A lot of what I have learned has come from observing clients birds, paying attention to my own birds or by talking to other bird owners. If you are unsure of an observation or behavior, it is always best to consult with your avian vet, and if he or she is not familiar with the species or behavior, it may be in your birds best interest to consult with the breeder that you purchased the bird from, or to have your vet consult with someone more experienced.

Copyright 2006 Margaret A. Wissman, D.V.M., D.A.B.V.P.
All Rights Reserved

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