The Not-so-hidden Link between 
Diet and Behavior    

by Pamela Clark
June 2001

As an avian behavior consultant, I often see a link between the specific behavior problem in question and the diet the parrot is eating. The old cliché, “You are what you eat” rings true for parrots as well as people. Avian veterinarians have known for some time that many clinical conditions are rooted in poor nutrition. When speaking of avian behavior, certain patterns regarding behavior and diet emerge repeatedly, lending credibility to the theory that diet has a profound affect on avian behavior, as well. Specifically, I have found that a dietary change can help to resolve the problem in some cases of aggression, many cases of feather picking or self-mutilation, and most instances in which the parrot repeatedly falls and breaks blood feathers.

Aggression and Screaming in New World Parrots

Usually, when I am contacted to assist with a behavior problem in a New World parrot, such as an Amazon, macaw, conure, or Pionus, the problem is aggression or screaming, or both. An examination of the diet often reveals that the bird is eating the majority of his diet in seed. Often, reducing the amount of seed in the diet to 10% or less, and increasing the amount of fresh, raw foods to about 70% can affect an improvement in the problems.

Why does this work? I can only theorize, since little is actually known about the diets of parrots in the wild. However, it appears that there is something about the consumption of large quantities of seed mixes that causes an adverse reaction in terms of behavior in these species. Several possible explanations exist. It’s possible that the fatty acid balance from temperate zone seeds is quite different from that of seeds that are naturally foraged. Or, it may be that a seed diet results in a lack of other nutrients not found in seed and that this causes such behavior. Another possibility is that the seed mixes fed in captivity have been contaminated in some way by fertilizers or pesticides and that these serve the basis for the behavioral change. Lastly, it’s possible that there simply is not enough variety in the diet, since the majority of birds consume the safflower, sunflower and peanuts from such mixes, leaving the smaller seeds. 

Of necessity, I am generalizing here. I must point out that the majority of the New World species about whom I consult are those common in aviculture. The specific species with which I have dealt that reflect this behavioral reaction to seed include Scarlet Macaws, Green-winged Macaws, White-capped Pionus, Blue-headed Pionus, Double Yellow-headed Amazons, Yellow-naped Amazons, Blue-fronted Amazons, Tucuman Amazons, Caiques, and others.

It should be noted that my observations might not pertain to the Caninde Macaw or the Hyacinth Macaw or others. In fact, a review of the natural diets of each New World species, as is contained in Joseph Forshaw’s Parrots of the World, reveals that there are certain New World species, such as the Slender-billed Conure, that do descend to the ground and eat grass seeds and others that are higher in fat. It must be remembered that each species is a distinct entity and may not necessarily follow the pattern I am describing.

That said, however, there is something of substance here to be examined. When I feed my own Blue and Gold Macaw, Yellow-collared Macaw, or my two Pionus a dish of seed, which they rarely get unless I am behind in my fresh food preparations, I can expect that without fail, they will be louder and more aggressive than usual. Other aviculturists have echoed this finding in regard to these species. 

The point to be taken home from this discussion is that, if you live with one of these species and the bird is mature and tends to be aggressive, a dietary change should be attempted for at least six months to see if this could be part of a solution. Rarely will a dietary change completely solve such a problem, although in one case I’ve handled it did. This could quite possibly be part of the solution to a quieter, calmer, less aggressive parrot. Dietary problems tend to have a cumulative effect. It can not be expected that a young parrot, not yet sexually mature, will yet have this sort of reaction. Thus, if you have a parrot whose species originates in Central or South America, and that parrot is still quite young, it would be advisable to pattern it early to eat a variety of fresh foods, more like the foods it would eat if in the wild, where it derives most of it’s nourishment from what is available in the forest canopy.

Feather Abusive Behavior

Feather picking is a devastating problem to parrot owners. I know of no other behavior problem, except that of self-mutilation, which causes owners such anguish. Feather picking cases are known to be difficult to solve, so much so that many vets do only the most preliminary of testing procedures before proclaiming the problem to be “behavioral.” To their credit, they do not have the time or the procedures in place, to fully evaluate environmental and dietary factors that also often contribute to the problem.

Rarely is a feather picking problem the result of one sole cause. In the vast majority of cases, there are several factors which, when combined together, push the bird “over the edge” into feather abuse. One of these is often diet. Further, I have found diet to be a significant enough factor that effecting change in this one area can cause significant progress towards the solution.

Feather Picking and Diet

I had begun to see certain patterns between diet and feather picking by the beginning of last year in 2000, when a veterinary student, Jeleen Briscoe, did an epidemiological study. Admittedly, Ms. Briscoe used a fairly small population (under 100 companion parrots who feather pick with a control group of fewer than 300) for study purposes. However, her goal was simply to prove that such an epidemiological study could be performed on such a complex problem, with valuable results. I believe she succeeded in her goals. Her findings were quite substantive and were similar to observations I had been making myself when working with clients’ birds who feather pick. Ms. Briscoe identified what she called “risk factors” for feather picking, 51 of them. Two of these were (1) eating more than 50% of the diet in pellets, and (2) eating Pretty Bird pellets.

The “risk factors” I have identified in my consulting practice provide ideas for expansion on Ms. Briscoe’s findings. Specifically, I have come to find that (1) eating extruded pellets containing chemical food dyes, and (2) eating a diet comprised mostly of processed and/or cooked foods will both greatly increase the likelihood that a parrot will feather pick. 

Dyes and Preservatives in Pellets

I would like to discuss the issue of pellets first. As I indicated, the pellets that seem most often implicated in feather picking cases are those that are the more heavily processed, extruded, varieties that also contain specific preservatives, in addition to chemical dyes. The two brands that crop up most often among the diets of my clientele are Pretty Bird (colored) and Zupreem Fruit Blend, with Kaytee Exact Rainbow running a close third. A fourth pellet that crops up more frequently than might be expected in cases of feather picking is Lake’s. 

An examination of the preservatives used in each pellet reveals that Pretty Bird and Lake’s pellets are both preserved with BHT. Zupreem is preserved with Vitamin E, while Kaytee Exact Rainbow is preserved with Ethoxyquin. The fact that Lake’s, which is un-dyed, has been implicated in cases of feather abuse, would appear to point to the presence of BHT as a risk factor. It is possible that this is why Pretty Bird pellets seem to be implicated more often than any other brand in feather abuse, as Ms. Briscoe concluded. The fact that it is both Pretty Bird and Zupreem Fruit Blend, which is only preserved with vitamin E, that are often also eaten in large amounts by feather picking birds would seem to suggest that perhaps the presence of certain food dyes are problematic for parrots, as well. These two brands contain, by far, the greatest amount of synthetic food dye.

It is not difficult to find numerous well-documented references to the adverse effects certain food dyes and preservatives can have on human health. As troubling as these are, even more alarming is the fact that, according to the “Summary of Color Additives Listed for Use in the United States” published by the U.S. Food and Drug Administration in November of 2000, certain color additives (astaxanthin, ultramarine blue, canthaxanthin, synthetic iron oxide) are approved for use in pet food, but not human food. However, little information is to be found regarding any health impact these might have, since they are not found in human food. However, among sources that provide information regarding food dyes regularly included in human foods, certain information appears consistently.

According to the Canadian Scholar’s Press Inc. (CSPI), the most widely used food dyes are Red 40, Yellow 5, and Yellow 6. Red 40 is perhaps the most widely tested food dye. The FDA review committee acknowledged problems with flawed testing of this coloring, but said that the evidence of harm was not “substantial” enough to without approval of its use. Yellow 5 is widely used in pet food and is known to cause mild allergic reactions in some individuals. CSPI had the following to say about Yellow 6: “Industry-sponsored animal tests indicated that this dye, the third most widely used, causes tumors of the adrenal gland and kidney. In addition, small amounts of certain carcinogens contaminate Yellow 6. However, the FDA reviewed those data and found reasons to conclude that Yellow 6 does not pose a significant cancer risk to humans. Yellow 6 may also cause occasional allergic reactions.”

Cochineal or carminic acid is another coloring agent that shows up frequently in both human and pet food, and is used to produce various shades of red, orange, pink, and purple. This red pigment is derived from the crushed female cochineal insect, which is harvested in Central and South America and the Canary Islands. The FDA does not require that it be listed on the labels of food products because it is considered a “natural” additive, since it is an “animal” product. 

It too is known to cause allergic reactions, some of them quite severe. A University of Michigan (U-M) news release dated 11/3/97 described the work of U-M allergist James. L. Baldwin, M.D. Dr. Baldwin had been successful in proving that it was cochineal dye in a Popsicle that caused a patient to go into anaphylactic shock. The process by which he showed proof that it was the cochineal dye that caused the reaction was published in the November 97 issue of the Annals of Allergy, Asthma, and Immunology.

The Feingold Association of the United States, well known for it’s work in allergies, recommends that people avoid the ingestion of Yellow 5, Yellow 6, cochineal (carminic acid), Red 40 and BHT, in addition to others. The yellow dyes have been heavily implicated in cases of allergies, as well as hyperactivity. If we look at the chemical structure of these widely used food dyes, it is apparent that they are large, organic molecules; large food molecules are often implicated in allergic reactions when insufficient enzyme activity in present.

I discovered a statement published by the CSPI that I believe is pertinent to this discussion. It states: “Most artificial colorings are synthetic chemicals that do not occur in nature. Because colorings are used almost solely in foods of low nutritional value (candy, soda pop, gelatin desserts, etc.) you should simply avoid all artificially colored foods. In addition to the problems mentioned below, colorings cause hyperactivity in some sensitive children. The use of coloring also indicates that fruit or other natural ingredient has not been used.” The information available in regards to the adverse impact of synthetic food dyes on human health is persuasive enough that it is not difficult to see how a parrot, whose physiology has not evolved to be able to deal with synthetic chemicals, could have problems when consuming them in quantity. However, this paragraph brings up another problem associated with these popular brand name pellets that could also be implicated in feather picking.

All three pellet brands mentioned above that are chemically dyed are also extruded pellets, as opposed to compressed pellets. Extruded pellets are made from a mash of ingredients heated to a high temperature. This mixture is then pushed by steam through a machine that presses it into shapes. The high temperatures necessary for the extrusion process are known to destroy enzymes, essential fatty acids (EFAs), probiotics, and vitamins.

Compressed (or cold-pressed) pellets are made with less heat. They look coarser in appearance. This type of manufacturing removes fewer of these valuable natural ingredients. These pellets also do not usually include synthetic food dyes, although some do contain artificial preservatives.

If we evaluate the live, raw foods eaten by parrots in the wild, we see that they contain abundant essential fatty acids and enzymes. An examination of the role each of these plays in good health will enable us to see more clearly why the consumption of extruded diets as a primary form of nutrition would be problematic to parrots.

Essential Fatty Acids

Essential fatty acids (EFAs) are called “essential” fatty acids because they are essential for normal growth and development, and they can not be manufactured by the body, as other fats can. They must come from the diet. If we look at the role these EFAs have in the body, we see that they are involved in many, many biological processes. Essential fatty acids are critically important in maintaining brain function, a strong immune system, and good eyesight, among other things. They are also vital for the healthy functioning of the nervous system.

The brain is largely made up of fat. This is “structural” fat, the kind that forms cell membranes and plays a vital role in how cells function. Neurons, the cells that transmit chemical messages are unusually rich in omega-3 fatty acids. The latter is an important fact, which the following will illustrate.

One of the first animal studies demonstrating a link between fat and intelligence was published in 1975. In this experiment, one group of rats was raised on a safflower oil diet, which is very high in omega-6 fatty acids but has only trace amounts of omega-3 fatty acids. A second group of rats was raised on a diet that contained an appreciable amount of LNA (the omega-3 essential fat). When tested in a simple maze, the rats raised on safflower oil made the right choice only 60% of the time, compared with a 90% success rate for rats whose diets contained an adequate amount of omega-3 fatty acids. Other studies have shown similar results. 

Further, it has been shown that omega-3 fatty acids help humans learn and remember. Human breast milk contains DHA (an omega-3 fatty acid), but infant formulas do not. Studies have documented that breast-fed babies have better visual acuity and scored higher on many tests designed to measure learning. In short, there have been ample studies with both animals and humans that prove beyond a shadow of a doubt that those provided with a good blend of essential fatty acids in the diet were capable of better learning and were happier.

According to Simopoulos, “If you foraged your food from the wild, it would be impossible to be deficient in this nutrient because it would be present in virtually everything you ate.” The author is referring to the plant-based form of omega-3 fatty acids – LNA. The omega-3 fatty acids are easily destroyed by light, air, and heat. Thus, an extruded pellet can contain no essential fatty acids – the very substances that are abundant in a wild diet.

Enzymes

Enzymes are another vital part of a wild diet that are destroyed by heat (above 118 degrees) and the manufacturing process. Enzymes are involved in every process of the body; they initiate all cellular activity. They breakdown the food that is consumed into small enough molecules that it can pass through the pores of the intestines into the blood. They are involved in the conversion of digested food into muscles, nerves, blood and glands. They play a part in sugar storage in the liver and muscles and turn fat into fatty tissue. They also aid in the formation of urea, which is eliminated as urine, and in the elimination of carbon dioxide in the lungs. Further, each enzyme in the body has a specific function.

In fact, it is enzymatic activity that creates the difference between live (raw) food and “dead” food. If you take viable seeds and boil them, they lose that viability that will enable them to grow if planted in the soil. Unboiled seeds will sprout because of the enzymes they contain. All natural foods in their raw state contain an abundance of enzymes. According to Humbart Santillo, MH, N.D., "Enzymes are always a part of animal and plant life. They are a component of living matter. Animals in the wild consume large amounts of enzymes as a result of their primary raw food diets. This aids in the digestive process, taking stress off organs such as the pancreas, liver, and spleen, which would otherwise have to produce large amounts of enzymes. This causes unwarranted stress on these organs and body tissues, thus decreasing the longevity of the body."

It was recognized as long ago as 1935 that unassimilated proteins, yeast cells, carbohydrates, and fats can be absorbed into the blood stream, causing allergies, skin diseases and other illnesses. This information was published that year in the American Journal of Digestion, Disease & Nutrition. Also published in this journal was research done by a number of physicians, among them Max Wolf, M.D. and Karl Ransberger, M.D., that showed that these conditions could be relieved by administering pancreatic enzymes to the patients.

Since enzymes are a part of every metabolic process in the body, it is readily apparent that a decrease in enzymatic activity could promote disease in humans. This is, in fact, what researchers have found and documented. Our white blood cells (leukocytes) are responsible for destroying disease-producing substances in the blood and lymph fluids in the body. Research has demonstrated that there are eight different amylase enzymes found in leukocytes. If we do not have adequate enzymes to fight infection, we will have an increased risk of disease, as well as allergies. Thus, there is a connection between the strength of our immune systems and our enzyme levels.

Interpreting Evidence

Earlier in this discussion, I indicated that I had also seen a relatively high incidence of feather picking in parrots who eat primarily table food. Since any cooked or processed food is, by definition, devoid of EFAs and enzymes, this would tend to corroborate the problem for parrots of consuming a diet that does not provide adequate amounts of both. When a creature evolves in the wild, their physiology often becomes dependent upon the nutrients present in the wild vegetation they consume. If selenium is present in the vegetation in relatively large quantities because the soil of that region tends to contain more selenium, that creature will evolve in such a way that it needs those same levels of selenium to function at an optimal level physically.

I believe we must be careful how we interpret the body of information I have presented above. Should we avoid colored pellets at all costs? Not necessarily. Although some believe so, the fact is that many parrots eat colored, extruded pellets in some quantity without apparent ill effects. Should we avoid feeding pellets to our parrots completely? I don’t believe so. In fact, I believe pellets to be an important part of a parrot’s diet for several reasons. Further, I have actually improved cases of feather picking in African birds by converting them to a diet that contained some un-dyed, compressed pellets that contain appropriate amounts of fat and protein for these species.

Is the lesson that we should absolutely feed some pellets to insure good nutrition, but we should just be careful which we choose to purchase? Not necessarily. If, in fact, chemical dyes do cause a problem for certain birds, we remain uncertain as to whether this reaction should be classed as an allergy or something else. However, parrots do appear to “react” to certain food products by feather picking, which is verified by the fact that the bird will stop picking when the offending substance is removed from the diet. An elimination diet can be implemented to determine which food is causing the problem. Although food allergies do not appear to be common, I do know of cases where a bird has reacted to a particular ingredient, such as corn or peanuts, in a good quality pellet. If this happens to be corn, pellets might need to be avoided since corn in such a common ingredient.

Thus, I believe there are several important lessons in all of this. 

First, we should question the issue of diet and strive to learn more about the nutritional needs of each species. 

Second, we should use our common sense when providing foods to our companion birds. This might cause us to compare what we are feeding to what they would be consuming were they still living in the wild. This is an appropriate guideline, since these creatures are not yet domesticated. They have nutritional needs that are identical to their wild cousins. Thus, it would seem to make good sense that their domestic diet provided to them should at least attempt to mimic their wild diet as closely as possible, while remaining mindful of other considerations, such as convenience and cost. 

Each of us must come to our own conclusions about how we juggle these sometimes opposing values. 

The final and most important lesson is to remember that we really don’t yet have enough information about the nutritional needs or the physiology of our parrots to be able to choose with certainty the ideal diet for each. Instead, we must feel our way along, remembering always that any food, no matter how nutritious, can cause problems for some parrots. Thus, if we have a feather picking bird, it is appropriate to closely examine diet and attempt to bring it more closely in line with what a “wild” diet might look like. During this process, it is advisable to eliminate from the diet any possibly “suspect” foods, such as food dyes, preservatives, and foods known to cause allergic reactions frequently in humans, such as corn, peanuts, etc. Upon removing these from the diet, the owner can then observe over time to see if improvement occurs. Once the suspect foods have been out of the diet completely for two weeks, they can then be added back in one at a time to see if a reaction occurs which worsens the feather picking.

Self-mutilation

Even more disturbing than feather picking is the problem of self-mutilation, which can become a life threatening problem as the bird rips into its own flesh, making himself bleed. While many of the same causes that lead to feather picking also lead to self-mutilation, the latter seems to be a behavior more resistant to resolution. Areas of the body targeted are most often the flesh of the chest, thighs and under the wings, although other areas are sometimes involved as well.

Although documented in numerous species, certain of these psittacines appear to be more susceptible to self-mutilation, among them Moluccan Cockatoos and Quaker Parakeets. The behavior is so often reported in the latter that it is now defined as Quaker Mutilation Syndrome (QMS). So common is QMS that it has drawn the attention of numerous veterinarians, who now believe that it is usually the result of a physical, rather than psychological, problem. It is often connected with Fatty Liver Disease, megabacteria and yeast infections.

In addition to examining the possible disease-related causes, the concerned owner of a bird that self-mutilates should also correct any possible contributory causes in the diet, such as potential allergens. The amounts of protein and fat in the diet should be scrutinized, as well. Some owners of Moluccan Cockatoos have reported improvement in the condition when animal proteins were added to the diet. While Forshaw makes no mention of this species eating any animals in the wild, cockatoo breeders in Australia have reported a practice wherein live mice are released into the flights for the birds’ consumption. This practice should at least cause us to wonder if wild cockatoos might consume such protein.

In the case of the wild Quaker Parakeet, Forshaw reports that they eat, among other things, insects and their larvae. In Argentina, they are known to eat meat left hanging in the trees to dry by local inhabitants.

Information such as this is not substantive enough to lead to any conclusions, especially in view of the fact that too much dietary protein also causes problems for some species. However, it does point up the fact that we have very little information about the relative amounts of both fat and protein and each species consumes in the wild. I hope that more exploration will be done in the future to see what link each might have to both feather abuse and self-mutilation because I believe that one exists.

Brittle Feathers 

Broken blood feathers are common in companion parrots and I am frequently asked to assist with cases in which a parrot falls often, breaking feathers each time as it does. This syndrome often begins with a too-short wing clip that causes the initial falling episode. Thereafter, a vicious cycle often develops, in which the bird startles and falls, breaks an incoming blood feather, is taken to the vet to have the bleeding feather pulled, then becomes more nervous as a result, falling more often, and breaking feathers more frequently. 

The parrot species that seem to have the greatest difficulty with this are African Greys, Senegals and Jardine’s Parrots. In the wild, Jardine’s Parrots feed primarily on wild olives and fruits of the oil palm, in addition to insects, seeds, nuts, fruit, flowers and berries. African Greys feed largely on fruits of the oil palm, as well as on seeds, nuts, fruits and berries. Senegals feed on seeds from shea butter trees, as well as seeds, grain, fruit, and leaf buds. (Interestingly, the other species of Poicephalus have not been recorded eating either fruits of the oil palm or seeds of shea butter trees.) In terms of behavior in the wild, all three species are described as “shy and difficult to approach,” information which underscores the fact that these species may be predisposed to developing fearful behavior in response to events like falling or having blood feathers pulled.

I have had good success in dealing with these cases by 

implementing dietary changes

 

modifying the environment 

 

modifying the owner’s handling techniques to minimize falling

 

using whatever means is available to decrease the birds’ overall anxiety and stress levels. 

 

 

Specifically, I have changed the diet to include slightly increased levels of complete protein and have supplemented with essential fatty acids, in addition to increasing the amount of fresh, raw foods eaten. I have been recommending that owners use an essential fatty acid oil blend from the health food store at the rate of up to ten drops a day placed on toast or some other absorbent food. Since oils and fats become rancid so easily, I feel more comfortable with the use of these since they have been refrigerated. In terms of adding animal protein into the diet, I usually recommend that owners feed scrambled eggs three times a week, in addition to switching to a compressed pellet that is higher in protein and fat. Eggs contain the highest quality protein of any known food. They also are a source of vitamin D, a necessary vitamin for regulating calcium and phosphorous absorption.

Feathers are comprised largely of protein, and I have surmised that insufficient levels of protein in the diet could contribute to lack of strength and integrity in new feathers. We do know that, in the wild, birds get a certain amount of their protein from eating fruit with insects in it. I have further assumed that low levels of EFAs in the diet could also be a part of this problem, since the wild diets of these three species contain significant amounts of fatty acids. This would appear to be correct, since increasing the levels of these seems to make a positive difference in the majority of cases. 

Summary 

So much is not known about this subject that even an attempt to write about it is difficult. However, my hope is that we will continue to keep a primary focus on the wild diets of parrots so that we will be better able to understand the nutritional needs of each unique species. I believe that it is perhaps no coincidence that many of the parrots who are known to sometimes be “difficult” in captivity are the same parrots about which we have the least information. Until more is known, I believe it appropriate to strive to provide the majority of a parrot’s diet as fresh, live food, and to make sure that protein and fat levels mirror as closely as possible what we know about their consumption of these in the wild. 

References 

Santillo, M.D., Humbart: Food Enzymes: the Missing Link to Radiant Health

Simopoulos, M.S., Artemis and Robinson, Jo. The Omega Diet

Udo Erasmus, Fats that Heal, Fats that Kill

Joseph M. Forshaw, Parrots of the World

Molly Siple M.S., R.D. Healing Foods for Dummies

http://www.quakerparrots.com/qms/qms_article_part1.htm

http://feingold.org/color_1.html

http://www.cspinet.org/reports/chemcuisine.htm

http://icn.umeche.maine.edu/icn/genchemlabs/Dyes/dyes1.htm