Diet: Past, Present, &
Beyond - Phytonutrition

by gloria scholbe
February 2002

Ancient Bird Keeping | Modern Bird Keeping | Seed Nutrition | Problems with Seeds | Development of Pellets | Problems with Pellets | Birds in Nature | Natural Diet | Geophagy | Evolving Nutritional Science | Phytochemicals and Phytonutrients in Foods | Importance of Variety| References

Ancient Bird Keeping
Parrots have amused and amazed humans since early Greek and Roman times. They were described in writings of Pliny, Solinus, and Apuleius as being "completely green apart from a red-gold band of feathers forming a collar around its neck." This description most likely applies to the normal color of Indian Ringneck parrot we know today. However, it could also describe The Alexandrine Parakeet, which was named for Alexander the Great. One story tells that an Alexandrine was given to Alexander as a gift after his invasion of Northern India in 327 B.C.

Parrot popularity, even then, was due in part for the parrot's ability to mimic words. Writings of the time describe a bird's' talking lessons and Pliny mentions, "it can be taught to greet emperors". One parrot learned many words including "Hail Caesar."

In addition to their talking ability, parrots were kept as cherished companions. An elegy by the poet Ovid, asks other birds to mourn the death of his mistress's pet parrot, obtained from eastern India. This bird was described has having emerald green feathers and a red and yellow beak. Another parrot, belonging to Frances Theresa, the Duchess of Richmond, supposedly died of grief a few days after his mistress. Her bird was placed to rest next to her effigy at Westminster Abby.

Wealthy Roman households assigned the task of caring for the family bird to a slave. These birds were kept in cages of precious materials like ivory and tortoiseshell and were fed almonds, nuts, and poppy seeds.

Only the very wealthy in Medieval and Renaissance Europe were able to keep birds. During this period, bird's cages were carved and painted. It was said that Madame Pompadour gave her parrots their food and drink in the best porcelains. In 1493 Christopher Columbus presented a pair of Cuban Amazon Parrots to Queen Isabella of Spain.

The first book in a series about the history of human-animal relations, eighteenth-century culture, and French colonialism by independent scholar Louise E. Robbins, Elephant Slaves and Pampered Parrots: Exotic Animals in Eighteenth-Century Paris, mentions that those looking for unusual pets could purchase parrots (and other animals) from the oiseleurs' (birdsellers') guild. She also describes how animals were transported, housed, and cared for.

Another book, Parrots in Captivity, by W.T.Greene, published in three volumes between 1884 and 1887, describes the diet fed to macaws as:
'maize, hemp, monkey-nuts, to which were added biscuits, nuts of all kinds, apples and fruit.'

Aside from this and a few other tidbits, very little is mentioned in early historical record about the diets fed to parrots. However, since parrots were mainly kept by wealthy folks, who could afford to incorporate more expensive and sometimes exotic nuts, fruits, and vegetables in their own diets, we can imagine that these foods were a part of their companion birds' fare.

It is unlikely that fields were maintained specifically for growing and harvesting bird-seed as is done today, but grains and seeds cultivated for human and animal feed, such as maize, wheat, millet, and oats, were likely offered to birds. No doubt some of these were offered in their processed form as flat breads, biscuits, cakes, and cooked/cold cereals.

Modern Birdkeeping
Cage bird popularity started to grow in the United States around the 1930's and that is when seed and feed companies started to import specialized seeds for feeding pet and wild birds.

During World War II, food was rationed and most crops were devoted to the war effort. Pet parrots were fed off of the family table. In her book, Parrots Their Care and Breeding, Rosemary Low offers some insight into what breeders were feeding their aviary birds during this period. Foods mentioned include: bread soaked in milk, cheese, germinated and dry sunflower, nuts, maize, berries, various fruit, hard boiled egg, cooked rice and other cereals, green foods (valued for their vitamin content), fruit, vegetables, cooked meat, properly cleaned maggots and other insect larvae.

After the war dry seed mixes became the dominant diet for pet birds. Some of the seeds used in these mixes included:

Sunflower is native to North America. Native Americans in present-day Arizona and New Mexico cultivated it from about 3000 B.C., thus it was probably domesticated before corn. The seed was ground or pounded into flour for cakes, mush or bread. There was little interest in sunflower as a U.S. crop until it was exported to other countries, especially Russia, where it was first commercialized. After that, it's value as a cash crop was realized in America. Sunflower would not have been a crop during ancient or medieval times in Europe, Asia, or Africa.

Millet was cultivated by the people Northern India since about 2500 B.C.. It spread to the Middle East, Northern Africa, and Egypt where it became a staple of the diet. In France and Italy, millet was cooked into various forms of porridge. Typical foods of the period in addition to millet were barley, wheat, chick peas, lentils, beans, onions, garlic, leeks, cucumbers, cress, mustard and lettuce. All of these foods would have been appropriate for birds. By the time of Charlemagne, the use of millet had spread to Europe. In France and Italy, millet was cooked into a porridge.

Safflower was originally grown for the flowers that were used in making red and yellow dyes for clothing and food preparation. In 1925 it began to be grown for oil. Varieties with higher oil content were valued. Two main varieties are presently grown: one type produces oil high in monounsaturated fatty acids (oleic acid), and the other is high in polyunsaturated fatty acids (linoleic acid). Today, safflower is grown for oil, meal, and birdseed.

Seed Nutrition
Seeds are produced by the mother plant to provide a package of nutrients that will enable a new plant to germinate, grow, and get off to a good start. This helps to ensure that the plant species will survive.

Many of the nutrients needed by plants for maintenance and growth are the same nutrients needed by humans, birds, and other animals. This is why seeds comprise part of the diet of humans and other animals.

Each plant species, as each animal species does, has its own nutritional requirements. As a result, each seed species will have a nutrient profile that is ideal for its own propogation. Some seeds are similar in profile and others are quite different. It all depends on the species from which it originated. Consequently, different seeds contribute different nutrients to those who consume them.

In addition to being a powerhouse of nutrition, seeds are considered to be 'live food' if they are still able to germinate. Live food contains enzymes and life-force energy in addition to the nutrients that can be physically measured. The benefit of consuming enzymes and life force is speculative and not completely understood. However, its proponents include nutritionists, physicians, and health care professionals who attest to its beneficial effects.

Sprouted seeds are living food. The actual chemical profile of the seed is changed upon sprouting. Most conscientious and successful bird breeders and keepers serve sprouted seeds to their birds.

Here is a table that analyzes seeds according to their gross nutrient profile. However, it doesn't list the specific amino acids or minerals. It just shows the variation between seed species. Seeds analyzed by different methods or that are grown in a different area may show percentages that do not match these.

%
Carbs
Protein
Fat 
Fiber
Minerals
Water
Anise 
33.45
18.12
11.60
13.35
8.20
12.78
Buckwheat 
64.43
10.02
2.24
8.67
20.2
12.62
Canary
37.23
 13.67 
3.52 
9.99 
21.29
 14.30 
Caraway
29.39
8.90
16.53 
16.34
7.39

 24.32
Corn
71.25
8.51
3.84
1.93
1.31
13.06
Fennel 
3.34
16.29
11.75
13.74
8.60
17.19
Flax 
22.10
24.28
36.5
6.3
3.75
7.06
Hemp 
15.89
21.51
30.41
18.84
4.6
8.75
Millet (White Proso) 
64.99
10.38
4.45
5.95
3.78
10.45
Millet (Yellow) 
62.82
11.7
3.3
8.1
3.78
10.3
Milo 
68.08
12.11
3.63
2.39
1.43
12.36

Niger Thistle
12.37
19.37
43.22
14.33
3.48
7.02
Oats 
52.28
12.07
4.42
11.92
3.35
9.96
Peanut 
17.73
27.95
35.75
3.04
2.36
13.15
Poppy 
9.96
21.10
50.02
5.4
6.86
7.90
Rape 
17.99
19.54
45
5.95
4.21
7.3
Rice 
64.52
8.29
1.8
8.89
5.02
11.68
Safflower 
13
16
38
15
8
10
Sesame 
18.63
21.12
46.78
5.0
6.02
5.61
Sunflower 
17.36
24
28.29
20
3.02
6.88
Wheat 
71.9
11.87
2.09
1.79
1.83
10.52

Sunflower- Sunflower seeds have been used traditionally not only as energy food but medicinally as well. Medicinally, sunflower seeds help to reduce allergic reactions, reduce cardiovascular problems, treat worms, and improve eyesight. Sunflower is is very high in many nutrients including minerals, vitamins, and essential acids. These are: high potassium/low sodium, protein, vitamin E, the B vitamins: thiamine, pyridoxine, niacin; minerals: iron, phosphorous, calcium, selenium, manganese, copper, and phosphorous; essential fatty acids: Linoleic acid and Oleic acid.

Pumpkin seeds are best known for their concentration of zinc. They have also been used in the treatment of intestinal worms. They are a good source of protein and contain a good balance of the amino acids, though tryptophan, methionine, and cysteine are a little low. Pumpkin seeds are high in iron, calcium, phosporous, magnesium, copper, Vitamin E, and B vitamins, and essential fatty acids.

Safflower is 16% protein and 38% fat. It also is high in B vitamins. 

Millet is a nonglutenous grain. It is the most alkaline of the grains and is potentially the least congesting. It contains 15% protein, is low in fat, has high fiber, good amounts of niacin, thiamine, and riboflavin, a little vitamin E, and some iron, magnesium, and potassium. Because of its low fat content, millet would be excellent to balance out some of the higher-fat flower seeds.

Problems of an All-seed Diet

No one seed species, by itself, will contain all of the nutrients required by a bird for long-term good health. Even combining a variety of seeds together may not provide complete nutrition for most birds. According to Dr. Randall N. Brue of Kaytee Products in Chilton, Wisconsin, most seed mixes fed to companion birds have these deficiencies:

Relying on seeds as the sole diet of most bird species will result in malnutrition. Some bird species will display signs of malnutrition earlier than others, depending on what that species requirements are. Signs of malnutrition in birds include:

Malnutrition is not limited to birds on an all-seed diet. Other diets, including formulated diets, can also contribute to malnutrition.

Hold These Thoughts:

  1. No single food or food formula exists that will meet the nutritional requirements of all species of birds
  2. Seeds are a natural and important source of nutrients that should be included as a part of most bird diets.
  3. Excluding all seeds from our birds' diets simply because they lack some nutrients, the same as all other food, is a poor dietary decision.
  4. An all seed diet causes malnutrition in birds.

The most detrimental aspect of feeding seeds to birds is the fact that most birds, when given a choice between seeds, fruits, and vegetables, will choose seeds. Many pet bird owners complain that their birds will not eat fruits and vegetables. Confronted with their birds' disinterest and waste, they stop offering anything but seeds. This in turn leads to malnutrition and the unfair reputation that seeds received from veterinarians and others who saw the results of an all-seed diet.

Many professional bird keepers and breeders have used and still do use seeds successfully as part of an overall healthy diet. This can be accomplished by utilizing a feeding strategy. Different facilities have used different approaches and those who use them claim they work.

Each bird keeper must determine if the bird is consuming a balance of foods from what is being fed. If the bird does not consume a healthy variety, then the owner must create a strategy appropriate for the particular bird. If one strategy does not work, then another should be tried.

Seeds are part of the natural diet of many birds in addition to all kinds of vegetation and insect or other animal protein. Pellets, on the other hand, are not part of any bird's natural diet, but they do offer the advantage of including some amino acids, vitamins, and minerals not found in seeds.

Development of Pellets
Pellets were developed in response to rampant problems of malnutrition that veterinarians saw in their exotic bird patients.

Because of the prevailing belief that seeds were the proper diet for birds, many pet bird owners were feeding seed and only seed to. Well-known bird trainers and behaviorists also fed their birds a mostly seed diet. Pieces of fruit or vegetable were considered 'treats' and were used as rewards for performing a task.

Many bird breeders, too, were feeding just seeds to their breeder birds as a 'maintenance diet' strategy. Only when breeding season arrived, would they include critically needed fruits, vegetables, and green foods to their bird's diets. Fortunately through hard-won education, this particular 'maintenance diet / breeding myth' has mostly died out.

As we saw from the previous page, a diet of seeds alone lacks several critical nutrients. Without these nutrients, birds will sooner or later, depending on species or individual needs, fall ill and die.

Between the '60 and the 80's, it was common knowledge that amazon parrots 'are prone to respiratory disease.' The same belief was held about Pionus parrots. In fact, neither Pionus or Amazons were 'prone' to respiratory disease. They simply were suffering from the absence of vitamin A in their all-seed diets. Vitamin A is needed to help fight respiratory and other diseases.

Stories about birds dying from egg-binding were common, as was the fact of spraddle-legged hatchlings. These problems were caused by deficiencies of calcium and/or vitamin D in their all-seed diet.

Responding to the need for improved captive bird diets, nutritionists, veterinarians, universities, and feed manufacturers began to develop formulated feeds for birds that would compensate for the inability of uneducated bird owners to provide adequate nutrition for their birds.

Pioneers in this field included:

Following their lead others quickly followed. Some of the better known include:

Two relatively recent pellet brands that use all organic ingredients with no added chemical preservatives or dyes are Harrison's Bird Diet and Foundation Formula. An added attraction of Foundation Formula pellets is the fact that this brand uses no added synthetic vitamins or minerals. According to the manufacturer, all vitamins and minerals are derived naturally from the nutrient-dense ingredients of the formula.

Problems With Pellets
Now, instead of feeding an all-seed diet, bird owners and some breeders began to feed an all pellet diet. Part of the reason for this was because the various pellet manufacturers claimed that their diet was complete, scientifically formulated by experts in avian nutrition, and should be the only food offered to the birds.

Because the typical bird owner has little knowledge of any nutrition, much less avian nutrition, they believed that only scientists were capable of feeding their birds. So, they followed instructions. Unfortunately for many birds, instead of suffering deficiencies of vitamins and minerals, birds now were suffering from

Soon the internal organs of some birds were becoming calcified and many began to die of visceral gout, kidney necrosis, arthritis, and other degenerative diseases directly attributable to an all pellet diet. It wasn't long before several pellet manufacturers changed their recommendation for owners to include 20% of fruits and vegetables in bird diets.

Even this did not solve all of the problems, and more nutritional disorders began to show up the longer that pellets were fed as the major diet. Feather plucking was seen more often than ever before. Nervous system disorders including toe-tapping and wing flipping became more prevalent. Polyuria, diabetes, fatty liver disease, elevated liver and protein levels, dry skin, behavior disorders, and a host of other health problems are all seen with an exclusive pellet diet.

Some health problems involve a reaction to the various additives included in the pellets to make them more appealing to bird and owner. Some of these additives include sugars, dyes, preservatives, flavoring, and odors.

Other health problems involve substances missing from the formula. For example, Omega 3 fatty acids are fragile and cannot withstand the heat processing of pellets without damage; therefore they cannot be incorporated into a pellet formula. Thus, the proper Omega3 to Omega 6 ratio of essential fatty acids is not provided in pellets. Other substances, from fruits and vegetation, that birds would normally obtain while foraging are not found in pellet ingredients.

Simply put, pellets do not contain the type of foods that birds evolved to forage in nature. Except for spirulina and/or dulse in three of the pellet brands and alfalfa in two of them, pellets completely lack green foods and other vegetation that in nature would comprise the major part of the diet of several species of parrots.

Although pellets are formulated to contain established percentages of protein, carbohydrates, and fats along with carefully calculated vitamins and minerals, these are based on the needs of poultry raised for slaughter or egg production. Such formulas are probably not even ideal for agricultural poultry.

Free range poultry, allowed to forage greens and insects from the field, produce better tasting eggs with brighter yolks and themselves have a better flavor when used as food. In addition, free range birds do not require a regimen of antibiotics or hormones as pellet raised birds do. Part of this is due to the conditions of their environment, but diet may have something to do with it also.

Again, maybe it's the kind of foods used to formulate the pellets. In nature, some parrots eat mainly seeds from various grasses. These species, like cockatiels, might do well on the grain-dominant ingredients of pellets if it were not for the vitamin/mineral formula of the pellets.

Other parrots consume very few seeds in nature. They evolved and thrived eating greens, buds, bark, leaves, insects, fruit, and some seeds. Grains and grass seeds are not a part of their natural diet since most of their foraging takes place in the canopy.

Is this significant? Carbohydrates are carbohydrates, aren't they? What difference does it make if carbohydrates, protein, and fat come from grains like wheat, corn, and soy beans....or if they come from leaves, buds, bark, and bugs?

The difference is that other 'nutrients' accompany the protein, fats, and carbohydrates in the various food sources. These nutrients are disregarded by present day avian nutritionists and thus are not calculated into the formula. These nutrients are called phytonutrients. (Fie'-toe nutrients) Phytonutrients are substances found in plants. Different plants have different phytonutrients. Different phytonutrients perform different functions within and for the body.

If a bird evolved to require the phytonutrients found in green foods then that bird could very well suffer from a yet undetermined form of malnutrition because those particular phytonutrients are likely not present in corn, wheat, or soy. How will this play out over the long term? It might or it might not. It all depends on how important that particular nutrient is to the individual bird. Additionally, the effects of its lack might not be recognized by the owner or by the veterinarian who sees the bird.

We do not yet have enough information about phytonutrients to establish dietary requirements for them. However, this is a growing area of study being offered in many colleges and universities in the field of Nutritional Sciences.

Some of the questions that concerned bird owners should ask the manufacturer of a pellet brand they plan to use include:

  1. Does the manufacturer maintain a test flock being fed these pellets?
  2. Is this diet the sole diet fed to the test flock or are other foods offered as well?
  3. How long has this flock been maintained on this diet?
  4. Is there a control flock for comparison?
  5. How often are physical exams and laboratory tests performed on these birds...both test birds and control birds?
  6. Specifically what tests are routinely run?
  7. Have any degenerative health problems manifested since the feeding trial began. (Degenerative disease include liver, kidney, gout, arthritis, and neurological)
  8. If so, what kinds of problems were seen?
  9. Are there any behavior differences between the test flock and the control flock? (Behavior refers to plucking, mutilation, activity level, stereoptypical behaviors, neurological.)
  10. Have any birds in the test flock died?
  11. If so, were they necropsied and what was the diagnosis?
  12. How many birds still remain in the test flock from the beginning of the trial?
  13. What is their condition compared to birds being fed this diet for a shorter period of time?
  14. What new birds have been introduced to the feeding trial?
  15. How long have these individuals been fed this diet?
  16. Are offspring from the original birds added to the test flock and to the control flock?
  17. Are there any physical or behavior differences between these birds and offspring in the control flock?
  18. Has the formula been changed or adjusted since the beginning of the trial?
  19. If so, how many times?
  20. What was the reason for the changes?
  21. Which species are maintained on this diet?
  22. Have all species performed equally well?
  23. Are different formulas offered for different species?
  24. Is the formula being sold and the formula used for the test flock the same formula?
  25. If not, why not and what are the differences?

Birds in Nature
 Life in nature is tough. Few wild birds live to old age and mortality of young birds is high. The major reasons for short life spans in the wild, if human causes are excluded, is starvation and predation.

Birds starve in the wild for a number of reasons. One reason is lack of food. During periods of drought and seasons when food is unavailable or in low supply, many birds simply cannot obtain the nutrition and calories they need for survival. However, birds have adapted to this situation by developing the ability to fly. Flight enables birds go where food is located. Another way that birds adapt to the food supply is their ability to obtain nutrients from a variety of sources. Most birds are not dependent on only one food source. If no fruit is available in the area, they can either fly to another area or eat something else, like seeds, buds, or a different fruit.

Despite these adaptations, birds still can starve. If a bird becomes injured, it may be unable to fly or forage. By the same token, if a bird is weak from bacterial, viral, or parasite disease, it may be unable to forage or may not be interested in eating. Young birds may not be skilled enough to forage successfully. They may not have survival instincts that keep them alert for predators. They might be too nervous and easily stressed, which makes them susceptible to disease.

Sick birds, weak birds, and inexperienced young birds can easily become victims of predators. That is the circle of life. Species of birds, like those on some Pacific islands evolved without natural predators. These birds would tend to have longer life spans as long as their environment and the food supply remains stable.

Some species' numbers have declined and some species have become extinct. This is due mainly to human interference, either by habitat destruction, 'harvesting', or by introducing non-native plants and animals against which the native birds have not evolved defenses. Another impact of human development into birds' environment is crop production. When birds raid domestic crops, they are not foraging the food supply that enabled them to thrive in nature. As a result, birds who rely on human crops for their nutrition tend to be malnourished and more prone to disease.

Even though nature is harsh, birds have managed to survive, reproduce, and increase their numbers to over 300 diverse species. The key to their success in nature lies in their evolutionary adaptation to food sources within the ecological niche that each species fills.

Natural Diet
Some bird species eat pollen, some eat bugs, and some consume only nectar. None of these birds compete with those who have developed large, powerful beaks for cracking open nuts and tearing into tough fibrous plant material. Each species occupies a different niche within the same environment. Each has its own specific nutritional needs that evolved out of the food sources its ancestors adapted to over thousands of years.

A pollen eater will not survive on the nutritional profile provided by nuts. A nut eater will not survive on the nutritional profile provided by nectar.

Field studies help to reveal the foods that birds thrived on in nature. These are clues to the nutritional requirements of our companion birds. Sources for this kind of information include: Parrots of the World by Joseph M. Forshaw and The Lexicon of Parrots by Thomas Arndt. Find out what your species consumes in nature and then find a nutritional analysis of those foods. This exercise will begin to give you an idea of which nutrients your bird needs, but it will not give you the whole picture because food science is still in its infancy. Much is still unknown.

According to numerous articles by nutritionists and naturopaths, synthetic vitamins do not offer the same level of nutrition as that found in whole foods.

The result of this and other similar studies, many of them double-blind placebo trials in animal and human models, are the reason that The National Institute of Cancer advises an increase of fresh fruits and vegetables in the American diet instead of several dietary supplements a day.

Still, supplementation of some kind may also be necessary. We are all aware that produce sitting in the markets loses nutrients as it ages. There is also the fact that nutrient depleted soils grows fruits and vegetables that are less nutritious than they were years ago. However, there are natural alternatives to synthetic vitamin/mineral supplements.

These alternatives are nutrient-dense green food supplements that include (but are not limited to) wheat grass, barley grass, spirulina, chlorella, kelp, alfalfa, nettle, and purslane. Green foods were our ancestors' original vitamin and mineral supplements. They are the most vital alive foods available for sustaining and protecting life.  There are thousands of unidentified and non isolated health molecules in green foods.

The nutrients in these foods are not synthetic, are better
absorbed by the body, are accompanied by companion nutrients, and they
function in a manner that physical bodies evolved to best use them.

Some people feel that birds should not be fed any foods other than pellets because many foods contain a variety of plant toxins. These include protein inhibitors (beans); oxalates (tomatoes, broccoli, spinach); tannins (nuts and seeds); cyanide (apple seeds); and more. Despite this, birds in nature manage to forage on a host of plants, fruit, and seeds that contain toxins. How do they do it? One answer being explored by biologists and other scientists is geophagy.

Geophagy
Many plants produce toxins as an evolutionary adaptation that protects them from being over-foraged, which would threaten their species survival. Most of the toxins are in the form of alkaloids and tannins that give the plants, their fruit, or seeds a bitter, sour, or otherwise bad taste.

Parrots number approximately 350 species. Most of them rely on fruits,
seeds, and other plant matter for food. Adaptations that aid in their food preferences include: strong beaks and tongues, oral dexterity and the ability to detoxify plant poisons.

It is a pretty well-known fact that birds are able to eat fruit that would be toxic to humans and other animals. Part of this has to do with their digestive system and their metabolism. Another part has to do with accommodation they make as part of their foraging behavior, which allows them to rid their bodies of the toxins contained in some of the foods they eat.

Studies and field observations of parrots in the wild by three separate groups have confirmed that parrots eat dirt to rid themselves of toxins. This is called geophagy (geo=earth phage=eat.)

One field observer is Charles Munn, who has been studying macaws in South America for years. The diet of the bird he studied was primarily seeds, many of which are toxic. They include seeds from mahogany, rubber tree, and more.

Munn observed that macaws spend at least two to three hours per day at a clay and mineral lick along a riverbed. By recording facial markings of each bird, he could track which birds visited the lick, how often, and the duration of their stay. Although his first impression was that the birds were obtaining either minerals or grit, he later concluded, from information about the toxins in seeds, that birds counter the tannins and alkaloids in the seeds by ingesting clay.

The clay helps to detoxify the birds by binding to the toxins, which are then eliminated from the body along with the clay. Current research is being done by Munn's group to isolate and analyze the specific toxins found in the seeds.

Another field scientist, James Gillardi, director of the Oceanic society, did his Ph.D. studies on geophagy in Amazonian parrots at U.C Davis. When Gilardi
measured the particle sizes of soils consumed by parrots, he found
that they were choosing extremely fine clays selected from a specific soil layer. These preferred soils are located along river beds in the southeastern corner of Peru. The soil bed preferred by the parrots he was observing was even finer than the soil immediately above and below it. From this he concluded that the parrots were not seeking grit.

Thinking that they might be interested in the mineral content of the soil, he analyzed the soils under conditions simulating those in an animal's stomach. What he found was that the soils contained even less of most minerals than the fruits the parrots ate. Additionally, concentrations of most minerals were no higher in the thin soil band that Gilardi's parrots selected than in the rejected bands above and below.

The third group of field scientists, Biologists Jared Diamond and David Bishop, observed birds at a site in New Guinea's Van Rees Mountains. As fortune would have it, they landed their helicopter at an area cleared by a landslide, which exposed a large amount of bare earth not covered by vegetation. This proved to be very attractive to hundreds of parrots, consisting of five different species, who visited the site daily.

The birds followed a daily routine. White cockatoos, palm cockatoos, eclectus, Pesquet's parrots, and lorikeets flew to the area in the morning. They would descend to the ground and eat the bare dirt. In the afternoon, the site was visited by different pigeon species.

Of the 140 bird species they recorded visiting the site, only eight species consumed the soil. These eight species were birds that foraged fruit, seeds, and flowers of various plants.

Jared Diamond writes: "While tracking down answers for my New Guinea parrots and other birds, I was fortunate to receive a letter from James Gilardi, then a graduate student at the University of California at Davis doing his Ph.D. research on geophagy in Amazonian parrots. Gilardi had gathered far more extensive data on geophagy by his parrots than Bishop and I could gather in our three weeks in New Guinea, and he was kind enough to carry out chemical analyses on some of our New Guinea soil samples along with his own Amazonian soils."

Analysis of these soils revealed that the minerals, kaolinite and smectite, contained in the soils at the Peru and New Guinea sites were particularly effective at binding toxins such as quinine and tannic acid. They proved to have 50 percent more binding capacity than the rejected soil bands immediately above and below the preferred soil band in Peru.

Note: This information is not intended to encourage pet bird owners to dig clay for their birds to eat. Not all clays or soils are useful for adsorbing toxins. Birds show very specific preferences. Feeding the wrong clay or too much of even the right clays might cause digestive disturbances or other harm to your birds.

Additionally, this information does not imply that we should feel free to feed known toxic foods to our birds. Birds learn from their parents which foods can and cannot be eaten, and some foods may have a fatal level of toxicity that parent birds teach their offspring to avoid.

Earlier in the article, we discussed the importance of nutrients that are less understood and therefore not included as a component of formulated feeds. What exactly are these nutrients and what can they do for our birds?

Evolving Nutritional Science
The National Cancer Institute has spent in excess of $20 million over the past several years researching and identifying plant substances in foods and herbs that provide protection against cancer and other diseases. These substances are called phytonutrients and phytochemicals. They include over 2000 known plant pigments; 1500 flavonoids; 600 carotenoids and 200 anthocyanins. Here is a list of some of them. Many more have yet to be discovered.

The American Dietetic Association (ADA) has published a position statement "that specific substances in foods (eg, phytochemicals as naturally occurring components and functional food components) may have a beneficial role in health as part of a varied diet. The Association supports research regarding the health benefits and risks of these substances. Dietetics professionals will continue to work with the food industry and government to ensure that the public has accurate scientific information in this emerging field."

As researchers continue to investigate the interactions of phytochemicals naturally present in food, evidence demonstrates that food components beyond those established as essential nutrients (protein, fats, carbohydrates, vitamins and minerals) are linked to disease prevention and treatment. This recognition is gaining acceptance among the scientific community and the general public.

Phytochemicals and Phytonutrients

Phytochemicals are nonnutritive plant chemicals that contain protective, disease-preventing compounds. Stephen de Felice, M.D., director of New York's Foundation for Innovation in Medicine, is credited with first use of the term nutraceutical. It describes specific chemical compounds found in foods that may prevent disease. Although phytochemicals are not yet classified as nutrients, they have been identified as containing properties for promoting health. The term phytonutrient better describes the compounds' "quasi-nutrient" status.

Phytonutrients found in fruits and vegetables were provisionally classified as vitamins: Flavonoids were known as vitamin P, cabbage factors (glucosinolates and indoles) were called vitamin U, and ubiquinone (CoQ10) was vitamin Q. Tocopherol is vitamin E.

Studies are showing that as we move away from the diet of our ancestors we succumb to modern diseases. It stands to reason that this is also happening with our birds. Researchers have examined epidemiological evidence comparing traditional with modern societies for clues to the diet-disease connection. On the basis of such studies, biochemical researchers have identified certain phytochemicals that aid the body in maintaining health and combating disease.

Scientists have grouped phytonutrients into classes on the basis of similar protective functions as well as individual physical and chemical characteristics of the molecules.

Class
Source
Function

 

Allylic Sulfides

 

garlic, leeks, onions, chives, scallions, and shallots.

 

Antimutagenic, anticarcinogenic, immune and cardiovascular protection. anti-growth activity for tumors, fungi, parasites, cholesterol and platelet/leukocyte adhesion factors. They boost the immune system, assist the liver in rendering carcinogens harmless, and may reduce production of cholesterol in the liver.Specific allylic sulfides block the activity of toxins produced by bacteria and viruses.

 

Anthocyanins - water soluble, reddish pigments found in many fruits

 

strawberries, cherries, cranberries, raspberries, blueberries, grapes and black currants.

 

Inhibit cholesterol synthesis.

Scavenge free radicals encountered in tissue fluids and they strengthen collagen by protecting its crosslinks. Collagen is the most abundant protein in the body, making up soft tissues, tendons, ligaments and bone matrix. Its great tensile strength depends on preservation of its crosslinks.

 

Capsaicin

 

 

hot red peppers

 

Reduce levels of substance P, a compound that contributes to inflammation and the delivery of pain impulses from the central nervous system. Research suggests it may inhibit cancer-generating substances.

 

Carotenoids -
bright yellow, orange and red plant pigments.

There are more than 600 naturally occurring carotenoids. alpha, beta and epsilon carotene are the only carotenes that are vitamin A precursers.

 

tomatoes, parsley, oranges, pink grapefruit, spinach and red palm oil.

 

Protect against lung, colorectal, breast, uterine and prostate cancers.

Carotenes are tissue-specific in their protection. Overall protective effects are therefore greater when all carotenes are taken together.

They enhance immune response and protect skin cells against UV radiation.

 

Catechins, Gallic Acids

 

All are found in green tea

 

Catechins differ slightly in chemical structure from other flavonoids, but share their chemoprotective properties. The most common catechins are gallic esters, named epicatechin (EC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG).

 

Flavonoids -
were once lumped together as vitamin P, but there are over 1,500 of them.

 

 

citrus, celery, cranberries, onions, kale, broccoli, apples, cherries, berries, tea, red wine, grape juice,

 

Enhance the effects vitamin C. Action against allergies, inflammation, free radicals, hepatotoxins, platelet aggregation, microbes, ulcers, viruses and tumors. Block the cyclooxygenase enzyme. Strengthen the vascular system and retard development of some cataracts

 

Glucosinolates

including isothiocyanates, dithiolthiones and sulforaphane. Each of these is protective of specific tissues.

 

cruciferous vegetables,

 

Activators of liver detoxification enzymes. Regulate white blood cells and cytokines.White blood cells are the scavengers of the immune system and cytokines act as "messengers," coordinating the activities of all immune cells.

Block enzymes that promote tumor growth.

 

Indoles

 

cruciferous vegetables (cabbage, kale, broccoli, cauliflower)

 

Bind chemical carcinogens and activate detoxification enzymes, mostly in the gastrointestinal tract.

 

Isoflavones

Phytoestrogens, also called isoflavones, have actions that are similar to the female hormone estrogen. Included in this class are genistein, daidzein, enterolactone, and equol.

 

Phytoestrogens are found in soy products (not soy sauce), beans and other legumes whole grains, berries, fruit, vegetables, and flax seed.

 

Antioxidants and tumor suppressors. Improve cholesterol, prevent bone loss, and suppress enzymes that stimulate breast cancer. Block enzymes that promote tumor growth.

 

Limonoids - subclass of terpenes.


 

 

citrus fruit peels

 

Inhibit tumor formation by stimulating the enzyme glutathione S-transferase (GST).

GST is a detoxifying enzyme that catalyzes the reaction of glutathione with electrophiles to form water-soluble compounds that are excreted from the body.

 

Lipoic Acid and Ubiquinone
(coenzyme Q)

 

  

 

Antioxidants that extend the effects of other antioxidants. Protect vitamin E and vitamin C. Lipoic acid also protects SOD, catalase and glutathione, which are all important in liver detoxification activities.

 

Lycopene

 

tomatoes, watermelon

 

Carotenoid that protects the prostate.

 

Lutein

 

blueberry, bilberry

 

Flavanoid that protects the eyes.

 

Phenols / Polyphenols are a large class that include flavonoids, catechins, quercetin, caffeic acid, ellagic acid, ferulic acid, and gallotannic acid

Blue, blue-red and violet colorations seen in berries, grapes and purple eggplant.

 

celery, cranberries, onions, kale, broccoli, apples, cherries, berries, tea, red wine, parsley, soybeans, tomatoes, eggplant, and thyme.

 

Antioxidants that suppress tumor growth, interfere with sexual hormones, help prevent blood clots, and have anti-inflammatory properties. Block specific enzymes that cause inflammation.

All block mutations of cancer in tissue culture and in
animal studies.

 

Phytosterols - are plant fats that
occur in the cell walls of most plant species. Cholesterol has long been implicated as a significant risk factor in cardiovascular disease. Are other dietary factors important as well?

 

 

pumpkins, yams, soy, rice, herbs, green and yellow vegetables contain significant amounts, their seeds concentrate the sterols.

 

Compete with dietary cholesterol for uptake in the intestines. Block the uptake of cholesterol and facilitate its excretion from the body. Block the development of tumors in colon, breast and prostate glands. alter cell membrane transfer in tumor growth and reduce inflammation.

 

Quercetin

 

red and yellow onions, kale, broccoli, red grapes, cherries, French beans, apples and cereals.

 

Anticarcinogenic activity and the ability to inhibit LDL oxidation

 

Saponins - forms of carbohydrates

 

ginseng, beans, including soy beans, and whole grains.

 

Neutralize enzymes in the intestines that may cause cancer. They also may boost the immune system and promote wound healing.

 

Terpenes - one of the largest classes of phytonutrients. Included in this class are carotenoids

 

green foods, soy products and grains,

 

Act as antioxidants, protecting lipids, blood and other body fluids from free radical damage

 

Thiols - Isothiocyanates and related substances, indoles, are also known as mustard oils and are responsible for the sharp taste in cruciferous vegetables .

 

broccoli, cabbage, Brussels sprouts, cauliflower, collards, kale, kohlrabi, mustard greens, rutabaga, turnips, bok choy

 

Stimulate enzymes that convert estrogen to a more benign form and may block steroid hormones that promote breast and prostate cancers.

 

Tocotrienols

 

grains and palm oil

Inhibit breast cancer cell growth, and have cholesterol lowering effects.

 

Xanthophylls belong to the carotenoid class. zeaxanthin, canthaxantin, cryotpxanthin, and astazanthin are xanthophyll carotenoids.

 

 

 

a variety of dark green, red, orange, yellow deeply pigmented foods including spinach, and peppers.

Protect vitamin A, vitamin E and other carotenoids from oxidation. Evidence is emerging that xanthophylls are tissue specific. Cryptoxanthin, protects vaginal, uterine and cervical tissues.

Canthaxantin migrates to the skin and protects it from UV radiation.

 

Specific Fruit

Strawberry extract paralyzes some viruses and makes them unable to
penetrate healthy cell membranes so they can't insert their DNA into the
cell for replication. Many fruit extracts have the same effect, even in
low doses. Fruits having the highest anti-viral activity are bueberry,
crabapple, cranberry grape, plum, pomegranate, raspberry, and
strawberry. Peach is least effective. Apple juice, red wine, and tea
were also effective. Researchers have identified the active antiviral
agents in the fruits to be tannins, which coat virus particles and
neutralize them.


Apple Pectin keeps the cardiovascular system healthy and helps
to regulate blood sugar.

Apricots are high in beta-carotene plus other unidentified
phytonutrients that are reputed in folklore to increase longevity.

Artichokes lower blood cholesterol and stimulate bile and urine
production. In 1969 French scientists took out a patent for artichoke
extract because of its success in treating kidney and liver ailments.
The active ingredient is cynarin.

Unripe banana and plantain is used in India for treating ulcers and
other stomach disorders by strengthening and thickening the surface
cells of the stomach lining. They trigger the release of a protective
layer of mucus.

Blueberry combats diarrhea (especially that caused by E.coli bacteria),
kills infections viruses, blocks damage to blood vessels (calcium/fat
build up), The active components are anthocyanosides. 

Broccoli contains potent cancer fighters: carotenoids, chlorophyll,
indoles, glucosinolates, and dithiolthiones. It also heals radiatin
sickness.

Brussels sprouts, along with cabbage and broccoli are part of the
cruciferous family that effectively fight cancer. The chemicals
identified are the same as those found in broccoli. The raw vegetable
contains antithyroid chemicals that are neutralized by cooking.

Cabbage is considered the longevity food. The lowest death rates are
found in cultures where the most cabbage is consumed. In addition to
fighting cancer similar to Broccoli and brussles sprouts, it boosts the
immune system, destroys bacteria and viruses, and contains an
unidentified 'growth factor'.

Cherries are used to cure kidney stones, gall bladder ailments, gout,
and reduce excess mucus production.

Chili peppers act as an expectorant, decongestant, and heal lung
ailments. They have been consumed to kill intestinal parasites.

Citrus Over 200 phytochemicals and flavonoids in citrus are anti- inflammatory, antitumor, inhibit blood clots and have strong antioxidant activity. The flavonoids, tangeretin and nobiletin inhibit tumor cell growth. Limonoids in citrus give citrus its bitter taste.

Orange and lemon oil contain substantial amounts of limonene, a terpenoid that also possesses anti-cancer activity. Citrus pulp and the albedo (the white of the orange) is rich in glucarates. Oranges also contain several different carotenoids.

Pink grapefruit contains high levels of beta- carotene and lycopene, the red pigment in tomatoes and guava that has a significant anti-tumor activity; tangerines and oranges contain high levels of other carotenoids (lutein, zeaxanthin, beta-cryptoxanthin). These carotenoids are associated with a lower incidence of age-related macular degeneration.

Figs fight cancer, kill bacteria, and fight roundworms. Enzymes called
ficins aid digestion.

Garlic fights infections and cancer, thins the blood, reduces blood
pressure, stimulates the immune system, relieves bronchitis, is an
antifungal and antibiotic. There have been over 125 scientific papers
published about garic. Allicin and sulpher compounds are garlic's major
weapons.

Kale is one of the richest of all green vegetables in carotenoids, which
are converted to vitamin A in the body and is high in chlorophyll.

Squash and its seeds for the carotenes and anti-worm propeties.

Fertility issues:
Peas contain substances that are an effective contraceptive.
Yams are rich in hormone-like substances that trigger the release of
other hormones, including FSH, which stimulate the follicles to produce
eggs.

Culinary Herbs

Substances that stimulate the activity of glutathione S-transferase (GST) inhibit cancer. These include the phthalides in celery seed, the sulfides in garlic and onions, the dithiolthiones and isothiocyanates in broccoli and other cruciferous vegetables, the bitter liminoids in citrus and the curcumins in ginger and turmeric

Rosemary, sage, oregano, thyme and other culinary herbs that belong to the Labiatae family are potent antioxidants. Rosemary and sage contain carnosol and ursolic acid, Ginger contains gingerols and diarylhaptanoids. The flavors of many common herbs and seasonings come from terpenoids, which help to fight cancer.

Importance of Variety
If you have read this far, it should be fairly clear that an all-seed diet, all-pellet diet, or even a combination diet of just seeds and pellets is missing a whole host of plant substances that were a normal part of the diet of our birds' ancestors. Science is just beginning to recognize how important phytonutrients are for maintaining health and preventing disease. Witholding them from the diets of our birds is equivalent to denying them the tools they need for good health.

Seeds and whole grains do contain some phytonutrients, but the greatest majority and variety of these chemicals are found in fruits, vegetables, and green foods. Although it is true that we cannot exactly replicate our birds' ancestral diet, we can approximate it by feeding foods that contain an array of phytonutrients similar to those they consumed in nature.

For example, birds whose diet was composed of a variety of berries should be offered berries in their captive diet, too. If the berries had blue pigments, the berries we feed them should also have blue pigments. If they were attracted to orange and yellow fruits, we should feed them the orange and yellow fruits available to us. If they foraged on a variety of fruits, greens, and seeds, then whe should feed them a variety of fruits, greens, and seeds.

We do not have to feed a variety every day. Birds do not necessarily eat a variety of foods every day. One day they might forage from a tree with blue fruit and the next day they might forage from a bush filled with new flower buds. But overall, the diet becomes varied. How and what they foraged was dictated to their ancestors by availability in nature and the seasons. This insured that over a period of time they would consume many different phytonutrients.

I have previously written two articles, one about Eclectus and the other about Jardine's. These articles included information about the natural diet of each species and how it should influence their captive diet. The articles speculate how missing phytonutrients in their captive diet may be affecting the health problems seen in companion birds.

Specialized feeders like lories, hyacinthine macaws, and others also have their own requirements. Look to the ancestry of your bird. It is a fascinating subject that will grant you better understanding of your bird and enable you to give it the best care possible.

References

Publications:
Steve Dale, Tribune Media Services The History of Birds as Pets
Jared Diamond, "Eat dirt: in the competition between parrots and fruit trees, it's the winners who bite the dust".. Vol. 19, Discover Magazine, 02-01-1998, pp 70(6).
John Doole, Parrot Sense
Rosemary Low, Parrots: Their Care and Breeding
Weston A. Price, Nutrition and Physical Degeneration
Tony Silva, Psittaculture
Toynbee, J. M. C. Animals in Roman Life and Art
Matthew M Vriends, Simon & Schuster's Guide to Pet Birds
W.T.Greene Parrots in Captivity

Online:
http://phytochemicals.tamu.edu/syllabus.html
http://www.eatright.org/aphytochemicals.html
http://ohioline.osu.edu/hyg-fact/5000/5050.html
http://micro.magnet.fsu.edu/phytochemicals/
http://www.wellnessweb.com/nutri/phytochemicals.htm
http://www.ars-grin.gov/duke/syllabus/module2.htm
http://www.realtime.net/anr/phytonu.html
http://www.andrews.edu/NUFS/phyto.html
http://my.webmd.com/content/dmk/dmk_article_5462459
http://my.webmd.com/content/dmk/dmk_article_5462460
http://www.ext.colostate.edu/PUBS/columnnn/nn980826.html
http://www.orst.edu/food-resource/c.html
http://www.parrotscience.com/uploadedarticles/geophagy.html
http://www.ansci.cornell.edu/plants/adapt/parrot.html