Potentially dangerous human foods!
Foods that may be toxic to your bird.
There are some foods you should avoid feeding your parrot because they are intrinsically too toxic. Foods that are toxic because of contamination with bacteria, fungi or mycotoxin are not included in this list. Almost all plant origin foods that people eat on a regular basis contain some residual toxicity, otherwise insects and other pests would destroy them. This is because plants must remain fixed in one location and cannot move away from their predators leaving an unacceptable taste or toxins are their only defense. Most of the plants people have domesticated have low levels of toxins. Civilizations have selected them because of their low toxicity or they have learned how to counter the toxicity by cooking or other means. While these plants may still possess a small amount of toxicity, they are unlikely to affect your bird. However, birds are much smaller than a person and the amount of toxin needed for an adverse effect is likely to be proportionately less. There are very few controlled studies in parrots of any of the foods in this list. If there are, I have tried to find and reference them. Unfortunately, most of the information is anecdotal or extrapolated from known toxicity in other species. In compiling this list, I first tried to find reports of toxicity for parrots, failing that, in other avian species. If there were none for birds I looked for toxicity in mammals, including people.
Not all the foods in this list are toxic for parrots. In fact, if properly prepared most probably are not. I include some foods because they are toxic to other species and sometimes they are toxic to just a small subset of individuals within a species. This is the case for most food allergies. I also include foods frequently mentioned as toxic to birds, but are probably not so toxic as other authors would have you believe. Examples of these are milk and the brassicas. I list other foods as a way to refute the popular notion that they are toxic, e.g. milk. I have tired to avoid anecdotal reports, but reports of the toxicity chocolate are so disturbing, I had to make special mention of them.
Oddly, there are very few good scientific reviews of intrinsic food toxicity. One of the best is by Ross Beier
Alcoholic beverages. Most parrots, including caiques, usually have little interest in consuming things like beer, dry wines, and other unsweetened alcoholic drinks. Their penchant for sweet liquids, however, may lead them to drink sweet alcoholic beverages. Like people, parrots get drunk if they consume too much. Alcohol has a deleterious effect on physiological markers in quail and turkeys when put into their drinking water. If their water contained 4 to 5 percent alcohol, it adversely affects the thiamin status of young turkeys
Alfalfa sprouts. The sprouts and seeds of alfalfa (Medicago sativa) contains the amino acid L-canavanine
Alliums—Onions, garlic, leeks, shallots, chives, etc. The small amounts of these used in regular cooking are unlikely to affect a parrot. Thus, you need not panic if your bird takes a bit from your plate. Some people feed a bit of garlic as a tonic, and this may be beneficial. However, you must not feed it long term or in excessive amounts. There is a report of a person force-feeding garlic to a dusky-headed conure which resulted in its death
Aloe. Aloe (Aloe barbadensis or more popularly Aloe vera) is often used as a tonic food for parrots (104). The latex that exudes from its skin, however, can irritate the large intestine of people. When taken in large amounts it can lead to red urine due to its anthraquinone content. This may be associated with nephritis
Annona fruit seeds. The annona family includes the atemoya, sugar or custard apple (A. squamosa) and the cherimoya (A. cherimola). The insecticide rotenone is present in the seeds of these fruits and rotenone induces a disease similar to Parkinson’s in rats (91). The seeds also contain annonaceous acetogenins that are active against parasites and microbes (84).
Apple seeds. When people consume a large number of seeds from the apple (Malus domestica) they can get very sick. It is uncertain if this is also true for parrots. The Carolina Parakeet, considered an agricultural pest at one time, would destroy whole apples just to get at the seeds
Apricot seed kernels. While the flesh of the apricot (Prunius armeniaca) is safe for people to eat, the seed kernel is not
Avocado. There are studies showing avocado (Persia Americana) is harmful when fed to cockatiels (40, 92)
shoots. Fresh bamboo shoots contain
cyanogenic glucosides and you need to cook them for human consumption. This
warning does not applied to canned bamboo shoots that cook during the canning
process. It is recommended that you peel away the outer leaves and fibrous
portions, then cut into thin strips and boil them for 8 to 10 minutes.
(Information from the
Basil (Ocimum basilicum)
contains estragole. This compound gives basil its distinctive taste, but it is
also a potent carcinogen in rodents. This compound also occurs in tarragon,
majoram, cumin, star anise, and other herbs and spices. The amount of the
carcinogen in these herbs, however, is hundreds of times less than that needed
to induce tumors in rats. However, the essential oils distilled from these herbs
contain very large amounts of estragole and you should avoid providing these to
your bird or consuming them yourself.
Raw and dried beans contain the toxin phasin. This warning applies to all beans
including the string or
green bean (Phaseolus vulgaris), red
runner bean (P. coccineus), kidney bean (Phaseolus
vulgaris), lima bean (P. lunatus), and jack bean (Canavalia
ensiformis). Canned beans
and beans cooked for ten minutes are fine since this denatures the toxin.
Ologhobo (2003) showed that feeding raw
BHA (butylated hydroxyanisole) is one of several compounds added to foods to
prevent oxidation of fats. BHA has some cytotoxic activity
. This antioxidant is less common that BHT in
processed foods for people and ethoxyquin in pet foods. (See BHT and ethoxyquin.)
BHT (butylated hydroxytoluene) is one of several compounds added to foods to
prevent oxidation of fats. BHT has some cytotoxic activity
; however, the National Toxicology program has
tested BHT and did not find it to carcinogenic
. Still, several countries have banned its use
in food products, and the
This is a family of woody vines of the Aristolochia
spp. Some of members of this group, such as Dutchman’s pipe, are grown as an
ornamental vine. Members of this group of plants produce the poison aristolochic
acid. This acid is cytotoxic and can activate oncogenes
. (Oncogenes are involved in the initiation of
cancers.) It is used in Chinese and folk medicine for various purposes,
including aiding the expulsion of the placenta after a child is born,
Unfortunately, it often kills the mother.
Almonds. While feeding of sweet
almonds (Amygdalus communis var. dulcis)
is very acceptable, feeding bitter almonds (Amygdalus communis var. amara)
is not. Like the kernel of the apricot, they contain a high level of amygdalin
and the ingestion of too many of these seeds will result in cyanide poisoning.
Bitter almonds themselves are not available in most stores, but almond oil is.
They press bitter almonds to make the almond oil used to flavor confections. You
should use this oil sparingly yourself and avoid feeding it to your bird.
People occasionally use the leaves and flowers of borage (Borago officinalis) in cooking. The leaves
contain pyrrolizidine alkaloids that are toxic for the liver. The raw flowers,
however, have a sweet cucumber-like taste and do not contain toxic alkaloids.
Chefs often use them to decorate foods. (Also, see comfrey)
Brassicas. The Crucifer or Brassica family is comprised of a large number of
edible cultivars. These include cabbage, kale, collards, broccoli, brussels
sprouts (all varieties of Brassica oleracea), rape (Brassica napus),
turnips (Brassica rapa), rutabagas (Brassica
(Raphanus sativus), etc. Early experiments indicated that when eaten in
excess, these were goiterogenic. They all contain glucosinolate toxins in their
seeds and leaves. Brussels sprouts are reported to have the highest levels of
. However, there are very few
reports of toxicity when mammals consume them. An exception is the feeding of
kale to cattle. This results in anemia due to S-methylcysteine sulphoxide or
“kale anemia factor”
. On the other hand, studies
indicate that eating brassica vegetables helps prevent colon cancer in people
. I routinely provide broccoli,
cauliflower and cabbage to my birds, but they usually eat very little. I have
also fed fresh radish seedpods to my birds without any problem. We know little
about feeding these to parrots. (Also see Rape seed.)
greens. Buckwheat (Fagopyrum
esculentum) greens and sprouts contains
fagopyrin which when ingested causes people to become photosensitive to sunlight
. Doctors call this condition “fagopyrism.”
This is a reddening of the skin accompanied by a burning sensation after the
fagopyrin accumulates under the skin and you expose your skin to light. It
usually takes a few weeks of consumption of greens before the symptoms appear.
This is not a problem with buckwheat seed or groats since they contain only
trace amounts of fagopyrin. (Some of this information is from the Townsend
or yuca (Manihot esculenta)
is a staple source of starch in
tropical countries. It contains the toxin linamarin which is metabolized to
cyanide by enzymes in our gut. Cassava is the source of tapioca. In
Celery contains furanocoumarins
capable of producing a “phytophototoxic”
. This response is typified by a vesicular,
peeling rash when exposed to light. It is particularly prevalent among produce
workers who must handle it daily. Whether furanocoumarins or any other factor in
celery can affect parrots is unknown.
Chamomile (Matricaria spp.) is a common
herbal tea. Some people, however, have an allergic response to it. It is a close
relative of ragweed, and some think they may share allergenic epitopes.
Excessive use can also cause diarrhea
seed kernels. Like other members of
the prunaceous fruits, the seed kernel is usually listed as toxic. However, Low
noted that the larger parrots often are in
such a hurry to reach it, they discard its flesh. She did not note any ill
effect on her birds.
Danger! Danger! Danger! This may be the one human
food you must absolutely avoid feeding your parrot. However, all the information
on chocolate’s toxicity for birds is anecdotal. There are several reports of
its extreme toxicity, a parrot ate some chocolate
and immediately became gravely ill
; an African Grey ate a chocolate donut and
; and a curious wild Kea apparently ingested
some dark chocolate and died
. People have fed very dilute chocolate milk,
etc. without ill effect
, so dose may be a factor. Chocolate contains
a compounds called methylxanthines, including theobromine and caffeine, that are
toxic for cats and dogs and they seem to be toxic for birds too
. Curiously, a native Indian in Brazil told me
that they call the caique the cocoa parrot because it likes to consume the sweet
gelatinous substance surrounding the bean in the cocoa pod. I was unable to
confirm if they ate the bean itself. It may be that only processed baking
chocolate and cocoa powder, both of which contain high amounts of
methylxanthines, are toxic.
beans. The data supporting the
toxicity of coffee and caffeinated beverages is weak. There is a report of the
effect of coffee bean seed, i.e., un-roasted beans, in which chickens
experienced reduced egg production and other adverse physiological damage. They
recovered once they stopped feeding them the beans
. I see no need to panic if your bird elects
to share a sip of your coffee or cola with you.
People have long used comfrey (Symphytum
officinale), a member of the Boraginaceae family,
as an herbal remedy. However,
people must limit their ingestion of comfrey since it contains
hepatotoxic pyrrolizidine alkaloids. When taken in excessive amounts it can lead
to liver disease. The main liver injury caused by comfrey is veno-occlusive
disease. It is also reported to be carcinogenic
. Comfrey is
considered so dangerous that several countries, including Germany and Canada,
ban its distribution
. With this in
mind, it is probably unwise to offer this to your parrot
. (Also see
oil or Red palm oil. Dendé oil, also known as red palm oil, is very high
in saturated fats. It is very popular in Brazilian cooking, particularly in Bahia.
Veterinarians sometimes recommend it for parrots as a source of vitamin A. This
may be excellent advise for the African Grey because it eats this oil palm fruit
in the wild
. Giving any bird a small amount
may be healthy for it. In large doses, however, it is dangerous for some birds.
noted that the natives of South
American sometimes feed it to birds in order to induce a bright yellow plumage.
These birds, however, develop severe liver lesions.
The locals in Southeast Asia call
the durian (Durio spp.) the “King of fruits.” However, they describe its odor as
something between rotting dead cats and unwashed socks. Durian is reputed to
exacerbate high blood pressure and tradition indicates that you should not eat
it with alcohol
. Every year, the newspapers of Thailand report one or two deaths from
eating durian (NY Times, April 8, 2007). Raw seeds should not be eaten because
they contain 1-Methylcyclopropene
that may cause shortness of breathe. However, people do eat the
seeds after they are roasted or boiled and then deep-fried. These seeds are a
treat in some cultures. We know little about durian toxicity for birds.
Some people feed the ripe berries of the elderberry (Sambucus
nigra) or European black elder to their parrots. I have fed the berries to
my caiques without any adverse effect although they did not really like them.
The twigs, leaves and unripe berries contain the toxin sambunigrin. Low
recommends them. Shropshire
fed the leaves to budgerigars and did not
find them toxic.
Some pet food manufacturers use ethoxyquin, butylated hydroxyanisole (BHA) and
butylated hydroxytoluene (BHT), to increase their product’s shelf life
. These compounds have antioxidant activity
that prevents fats from turning rancid. Manufacturers are not permitted to add
ethoxyquin to any human food products. Ethoxyquin has been reported to cause
chromosomal damage in human lymphocytes
and nephrotoxicity in male but not female
. On the other hand, the addition of
ethoxyquin has been shown to reduce the toxicity in chickens of peroxides that
develop in feeds when they are stored
and reverse the effects of lead contamination
of poultry feeds
. The Federal Food and Drug Administration
(FDA) states that it has no reports of its toxicity when used in dog food
. Nonetheless, the FDA also recommends that
you feed a pet food from one manufacturer for only a few months since not all
manufacturers use the same ingredients and preservatives. The wisdom of
switching around among manufacturers should become an accepted practice. The
recent contamination of pet foods only serves to emphasize this point.
beans or Broad beans. The faba or fava beans (Vicia
faba) are toxic to people genetically
sensitive to them. In these individuals, it causes “favism,” a form of
hemolytic anemia. This is usually sex linked with men being more predisposed to
favism than women. These individuals lack the enzyme glucose-6-phosphate
dehydrogenase. They believe the cause is a compound called vicine. There are
many reports on the adverse effects of feeding raw fava beans and their hulls to
chickens. Most report a decreased egg size and loss of fertility.
Fiddle heads. See Ostrich fern.
Fresh figs (Ficus
carica) have some toxicity. Some people develop contact dermatitis to fresh
figs. This does not seem to apply to dried figs. I doubt that parrots have the
same response. I have been feeding dried kalamata figs to my caiques for years
without ill effect. They eat the tiny little seeds and leave behind the outer
husk-like skin. My caiques are not
as fond of the fresh figs sold in markets as they are of the dried ones. Wild
caiques eat the wild figs of South America
. If you own fig-parrots, it is almost
mandatory that you feed them figs.
Some people develop an allergy to ginger (Zingiber
officinale). The allergic response is usually mild causing only flatulence.
Severe responses take the form of constriction of the throat and burping to
relieve the build up of gas.
The fruit of the ginkgo (Ginkgo biloba) is consumed by some oriental peoples. The juice of
this fruit is thought to be toxic for people.
of Paradise. This spice, the seeds
citratum is rapidly gaining wide use. It is typically
used in place of black pepper corns. I have found no reports of toxicity for
people or birds. It is toxic to snails
, and may be helpful in preventing infection with the parasites borne by
There is very good evidence that anyone on certain medicines should avoid
. There is a very long list of medicines
affected by drinking grapefruit juice. Typically, grapefruit juice has the
effect of greatly increasing the blood level of these medicines by promoting
better absorptions of them from the gut. Deaths due to overdoses of medications
can result from drinking grapefruit juice. You should probably avoid feeding
your bird grapefruit is you are medicating it. The grapefruit is thought to be a
hybrid of the pomelo (Citrus maxima)
and the sweet orange (Citrus sinensis).
Orange juice does not to have the same effect.
Grated horseradish (Armoracia rusticana) is a common condiment. Excessive
exposure, usually by people grating it, can lead to irritation of one’s mucus
membranes. Other than that, it is generally safe for human consumption.
Insects and insect larvae. Aviculturalist frequently feed insects, insect eggs and insect larvae to their birds. These include waxworms (Galleria mellonella) (52) , meal worms (Tenibrio molitor ) and crickets that can be purchased as many pet stores especially ones catering to amphibians and reptiles. Caiques and other parrots greatly appreciate these and they are safe to feed. It is when you gather larvae from the wild that you need to be careful. There is a report of a person who routinely fed the “common green inchworm” to her birds, on one occasion she gathered some that had been feeding on an azalea. She fed these to several non-parrot species including Dybowski’s Twinspots (Euchistospiza dybowskii), Black-cheeked Waxbills (Estrilda erythononotis) and Purple Grenadiers (Uraeginthus ianthinogaster). These birds developed labored respiration, paralysis of the legs and feet, and other clinical signs (116) . The toxin affected them for several hours before they recovered.
Kava or Kava-kava. The peoples of Pacific Oceana regularly consume Kava (Piper methysticum). It has psychoactive properties, but is not addictive. It is sometimes sold in health food stores, although it has been banned in Germany, France, Switzerland, Australia and Canada because of its toxicity for the liver (2, 26)
Kumara. Kumara is a variety of sweet potato (Ipomoea batatas) with a unique taste grown in New Zealand and other parts of the South Pacific. When injured or attacked by molds or insects it produces a toxin called ipomeamarone. This gives the potato a bitter taste. Moldy kumara are been reported to have killed cattle. You should remove damaged parts of the tuber before cooking and do not eat if it tastes bitter. (Information from New Zealand Food Safety Authority.)
Lactobacillus. Scientists often tout Lactobacillus as a probiotic that affords people protection from other gastro-intestinal pathogens and there is evidence that this does work for people. There are several Lactobacillus species. Because of its efficacy in people, some owners provide Lactobacillus to their birds; however, this probably is not very effective. The reason for this is that Lactobacillus ferments lactose, which is present in milk, and most of the foods we feed our parrots do not contain it. Further, in order for the bacteria to hang around in the gut, it needs to attach to the gut wall. For this it needs the proper receptors on the intestinal wall, which I doubt lactobacillus has in birds. There has been a study of Lactobacillus acidophilus in cockatiel chicks, but the addition of the bacterium to the hand-feeding formula did not prove very useful (109)
Licorice root. The licorice (Glycyrrhiza glabra) root contains glycyrrhzic acid that affects the adrenal gland’s capacity to regulate sodium and water balance. However, to notice any adverse effect one has to eat a large amount of black licorice for several months. People disposed to edema hypertension should avoid eating licorice.
Lupin or Lupine seed. They harvest this seed from members of the same group plants that contains the ornamental flower. Lupine seed and fodder (Lupinus angustifolius, L. albus, L. luteus) is sometimes fed to chickens and live stock because it is high in protein. McGrath
Mango. The sap and skin of unripe mango (Mangifera indica) contain a number of compounds that are strong skin irritants. Some people develop a hypersensitivity to these irritants (75). For these people, they recommend using one knife to peel the fruit and another to cut off the flesh from the seed. You should not burn its wood because it produces irritating vapors. I have fed mango to my parrots without ill effect.
Milk. Many experts claim you should not allow your bird to have milk or dairy products. They seem to believe that birds are like people who suffer from lactose intolerance. While birds do not have an enzyme for digesting lactose, this does not mean they have the same adverse reaction seen when lactose-intolerant people drink it. Indeed, milk is rich in protein and calcium. Because of this, many respected, mostly early, aviculturalists offered it to their birds. Bechstein (10) found milk very beneficial for birds in the early nineteenth century; Low (67) believed it was important to provide it to birds when they are rearing their young; while Stoodley (102) advocated providing skim milk as a source of essential amino acids. Lee, one of the first to hand rear parrots, included dilute raw cow or goat milk in the formula he fed every few hours to African gray chicks (62). The argument against milk is that certain bacteria, if present in the bird’s gut in the bird’s gut, will ferment the lactose and cause diarrhea. It is true that the presence of lactose in a chicken’s diet does yield less “compact” excreta (33), but it is hard tell if a bird has diarrhea since both urine and fecal matter collect in the cloaca and are expelled together (39). Thus, this may only be a problem for maintaining cleanliness.
Of course, one should not allow one’s bird to overindulge, and in the case of caiques this is very unlikely. Avian nutritionist Tom Roudybush (87) did not see any problem with providing parrots with milk, especially low fat milk, as long as the bird’s total diet contained less than 10 percent lactose. Several studies indicate that lactose can comprise up to 20 percent of the diet without adversely affecting the growth of young chickens (33, 36, 37). While another study indicated that feeding lactose to young chickens actually accelerated their growth (89). Some recent studies suggest that lactose can serve as a “prebiotic” that helps fend off some bacterial infections in chickens (29, 30, 119). I agree with Roudybush that feeding milk in small amounts is not harmful, and my pets often share my breakfast of milk and cereal even though I do not offer it as a regular menu item.
If you remain concerned about lactose, you can still feed your bird a dairy product. One of these is the whey protein isolated as a byproduct of cheese making. Modern production methods now render this quite pure and free of lactose. You can buy whey in health food stores catering to the body builders. The other lactose free dairy products are those that are fermented in their production, i.e. yogurt and cheese. While young cheeses still contain some lactose, the general rule is the older the cheese the less lactose. Both yogurt and cheese are excellent sources of calcium and amino acids that parrots need, especially when they are breeding. The chief problem with these is that they usually contain high levels of saturated fats. I provide my caiques with a small half-inch cube or smaller of cheddar cheese daily. They tend to prefer yellow cheese to white cheese.
Nectarine seed kernels. See Apricot seed kernels.
Niacin. People, and presumably birds, need dietary niacin (vitamin B3) to survive; however, consuming it in excess can be dangerous. When a group of people accidentally took a dose of 190 mg they developed a rash, pruritis, and a warm feeling. Fortunately the symptoms were of short duration
Nutmeg. People sometimes abuse nutmeg (Myristica fragrans) by taking it in high doses to achieve a legal high. Those who have done this, however, note that they experience a horrible hangover. Because we do not know its effect on birds, it is best avoid allowing them access to nutmeg.
Olives. Uncured olives contain oleuropein, which is very bitter. If you eat one, the bitterness will linger for hours. This is why olives are cured either by treating them with lye or other pickling process to destroy or leach out the oleuropein (New York Times, Oct. 17, 2007). Aside from their extreme bitterness, there is little evidence that fresh olives are toxic to people.
Oils. Cooking oils can be toxic to your birds. The chief danger for birds comes from frying with olive oil. This was the sad experience of a parrot owner who killed his birds when he decided to fry food in olive oil in his small, poorly ventilated travel trailer
Ostrich fern. The emerging sprouts of the ostrich fern (Matteuccia struthiopteris) provide the gourmet delicacy called “fiddle heads” or “crosiers.” In their raw form, they contain a toxin that leads to gastric distress including nausea, vomiting, and diarrhea. Health Canada recommends that these be boiled for at least 15 minutes or steamed at least 10 to 12 minutes for human consumption (6). We have no idea of their toxicity for birds.
Oxalic Acid. This acid is present in many of the plant foods we eat. Those with a high concentration include rhubarb and sorrel. However, oxalic acid is present in tomatoes, spinach, and other commonly eaten plants too
There is another problem with oxalic acid beyond its capacity to kill. Problems can develop from long-term consumption of foods containing oxalic acid. Oxalic acid is a strong binder of polyvalent metal ions, particularly calcium ions. This can cause nutritional deficiency. Oxalic acid can also exacerbate some diseases. They recommend that people with kidney disorders, gout, rheumatoid arthritis, and some other disorders avoid foods containing oxalic acid. The composition of one type of kidney stone is calcium oxalate. Thus, it is probably a good idea to avoid feeding foods rich in oxalic acid to your bird, especially gravid hens that need calcium to form eggshell.
Papaya. The unripe papaya (Carica papaya) contains the proteolytic enzyme papain. While the ripe fruit still possesses a small concentration of the enzyme, it is not enough to warrant avoiding. Indeed, you should encourage you parrot to eat ripe papaya as much as possible since it contains nutrients, especially vitamin A, that parrots need
Parsnips. Parsnips (Pastinaca sativa) contain furonocoumarins. These are concentrated on the outer surface layer and in damaged portions of the parsnip root. They recommend that you peel and cook parsnips for human consumption. Feeding diseased parsnip roots to mice adversely affects their liver and tissues (74) . The leaves and stems are also thought to contain toxins. (Also see celery.)
Pawpaw. The pawpaw (Asiminia triloba) produces edible fruit that can cause dermatitis and severe gastroenteritis in sensitive people
Peach seed kernels. The flesh of the peach is an excellent food for parrots. The kernel of the peach seed has a toxicity similar to that f the apricot. However, I would not worry too much if one on my birds ate one or two. Low
Peanuts or Groundnuts. The peanut (Arachis hypogaea) is pervasive in the diet of much of the world. However, some people are so allergic to them that a single nut or even the dust from a peanut can be fatal. There is no evidence of any such problem for birds, and, indeed, most parrots find them a great treat. Obviously, if you are allergic to them, you should not feed peanuts to your bird.
Pear seeds. See Apple seeds.
Peppers. There are a wide variety of peppers or chili peppers. They all belong in the Capsicum genus. The pepper itself is a berry and not toxic to birds. Other parts of the plant, however, may be toxic and this is mentioned under Solanaceous plants later in this list. Peppers are ubiquitous in our diet, and we grade them by their “hotness” or piquancy. Bell peppers have no piquancy at all, but most people cannot tolerate eating a raw habanera. Birds do not have the same response to them as mammals (50, 51). In fact, it is thought that the existence of the compound capsaicin in hot peppers evolved as a way for the plant to limit its eating to birds (108). Studies at the Virginia Tech University indicate that if you feed capsaicin to chickens it protects them from Salmonella enterica, formerly S. enteritidis. This bacterial species causes food poisoning of people. Because only birds seem to be able to tolerate hot peppers, some people add them or their juice to their wild birdseed to keep the squirrels and other vermin from eating it. (See also Solanaceous plants.)
Persimmon. There are three species of persimmon commonly sold in our markets. They are the American persimmon (Diospyros virginiana) and two Asian varieties, the lotus (D. lotus) and kaki (D. kaki). The kaki is the most readily available. The fruit as sold in the market is very astringent due to tannins. There are two ways to overcome this astringency. One is to allow the fruit to ripen completely. The other is to freeze it until it is completely hard and then allow it to thaw completely. Persimmons are not toxic per se, but on rare occasions they cause an rare intestinal obstruction called a phytobezoar (117). The persimmon’s tannin can polymerizes in the stomach and in susceptible individuals this leads to bezoar formation (46)Consuming the fruit’s skin greatly increases the chance of bezoar formation. A bezoar is any fibrous mass that accumulates in the intestine that results in a blockage. They can be the result of eating a large number of other high fiber foods including oranges, coconuts, berries, green beans, figs, apples, sauerkraut, brussels sprouts, and potato peels (34). It is a particular problem for young people, people who have had gastric surgery, and those who suffer from stomach ulcers (23). Phytobezoars rarely occur in birds. Nonetheless, Clipsham suggests that you should not feed persimmons so birds (25), however, there is little evidence to support this assertion. I have fed persimmon to my birds on occasion without ill effect; however, I tend to avoid feeding them because both the very ripe and the freezer treated fruits are extremely gelatinous making them difficult to cut into serving pieces. This is one instance where you should avoid feeding the fruit’s skin.
Pine nuts. They harvest pine nuts from a number of pine tree species belonging to the Pinus genus. There is no evidence that pine nuts are toxic for parrots or other birds and, indeed, they are a favorite treat. Some people, however, have an allergic response to them that precludes them from feeding them to their birds
Pokeweed. The young sprouts of the pokeweed is (Phytolacca americana) are sometimes consumed in salads and as a tea. You must always cook them, and you must avoid the root and berries. Swine seem especially sensitive to pokeweed poisoning. Some North American songbirds eat the berries, but they are poisonous for young turkeys.
Potato. I cover the toxicity of the potato (Solanum tuberosum) under the Solanaceous plants. The green tomato-like fruit of the potato is especially dangerous. In addition to toxins, ingesting the skin of the potato by gastric surgery patients can also lead to phytobezoars
Plum seed kernels. See Apricot seed kernels.
Prunus species. The prunus species includes apricots (Prunus armeniaca), nectarines, peaches, plums, and cherries. The flesh of the fruit of these fruits is perfectly safe, but their pits, bark, and leaves contain toxins. (See apricot seeds.)
Rapeseed. Rape (Brassica napus) is a member of the mustard or Brassica plant family. In the past, rapeseed sometimes made it into commercial canary seed mixes. However, there is a serious difference in types of rapeseed. While both are high in protein, one type is safer to eat than the other. The original use of rapeseed was of limited to the production of oil to lubricate steam engines and burn as a lamp oil. Occasionally this oil makes it into the human market and results in “toxic oil syndrome.” This syndrome includes serious neurological symptoms. They feed the seed to animals, but only in limited amounts since it has a high level of glucosinolates and uric acid. Feeding of rapeseed meal to leghorn chickens can cause liver hemorrhage (20). Canadian agronomists were able to develop a much safer form of rapeseed that they named Canola™. The oil pressed from the Canola seed is now sold in most groceries and both the seed and oil from this plant are safe for human, and presumably for avian consumption (45). (Also see brassicas.)
Rhubarb. The leaves of rhubarb (Rheum rhaponticum) contain high levels of oxalic acid. The stalk contains a much lower concentration, and we can eat them without undue worry. (See oxalic acid.)
Saint John’s Wort. While not considered a food, people sometimes use St. John’s wort (Hypericum perforatum) as a home remedy. This herbaceous plant produces the toxin hypercin.
Salt. Salt, NaCl, can be toxic to birds when fed in large amounts. Parrots can develop salt poisoning if you feed too many salty foods such as salted peanuts and potato chips
Sassafras. People sometimes brew a tea from the bark of the sassafras (Sassafras albidum) root. This tea contains the toxin safrole, which is hepatocarcinogenic
Sorrel. They sell the leaves of French (Rumex scutatus) and occasionally garden sorrel (R. acetosa) as an herb for use in sauces and soup. These leaves are rich in oxalic acid and this acid binds calcium ions very strongly. They do not recommend that people eat too much of this herb, and the same probably applies to parrots, especially hens during the breeding season. (See oxalic acid.)
Solanaceous plants. These include the tomato (Solanum lycopersicu), potato (Solanum tuberosum), eggplant (Solanum melongena), tomatillo (Physalis ixocarpa or Physalis philadelphica), peppers (Capsicum sp.), and tobacco (Nicotiana tabacum). You need not worry about feeding ripe tomatoes and peppers. Caiques have a great fondness for the seeds of the tomato and pepper. Just be sure to remove the green vines and stems. Aviculturalists have been feeding these for years. However, they almost never feed tomatillo, eggplant, potatoes, or tobacco. You should take care to prevent your bird from eating certain parts, particularly the green parts, of these plants. Some parts of these plants contain nicotine and/or the glycoalkaloid solanine that are poisonous. Ingestion usually does not cause a serious condition; however, there have been cases of death. (Also see potato.)
Soybeans. This warning only applies to raw soybeans (Glycine max) fed as a regular diet. Geese fed raw soybean meal exhibit reduced growth, pancreatic enlargement, and other adverse effects. This may be due to the high concentration of trypsin inhibitor in the raw meal edamame, which are fresh soybeans blanched in the pod at least 5 minutes in boiling water and thoroughly cooled. Processed soy meal is a frequent ingredient in formulated diets. However, if you feed large amounts of soy meal without supplementation, birds are less fertile as a result of a low serum thyroxine level due to goiter. This may be overcome by supplementing the meal with iodine (97). Tofu and unsalted roasted “soy-nuts” are probably no problem (21). Some people have an allergy to soy. If this is the case, you will have to avoid feeding it to your bird to protect yourself.
Spirulina. Health stores and some pet shops sell spirulina as a dry powder. “Spirulina can be any of a number of species of blue-green algae. People can develop an allergy to spirulina and they should avoid consuming it. Some people believe their pet birds develop a similar allergy. http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-spirulina.html.
is a potent inhibitor of CYP3A. For more on
this see the entry on grapefruit. As noted under the grapefruit entry, the juice
of this fruit increases the absorption of some medicines from the gut, sometime
causing death from an apparent overdose.
seed. It is my opinion that one
should not feed parrots sunflower seeds as a regular part of their diet.
Unfortunately, most seed diets intended for parrots are predominately composed
of sunflower seed. Parrot are so fond of sunflower seeds that they will pick
them out and ignore all the other seeds. Caiques on a high sunflower seed diet
develop abnormally colored feathers that give them a “pied” appearance. This
is a result of a failure of the feather follicle to deposit melanin in the
feather when it forms. Based on the nomenclature of Buckley
, I refer to the this as a “localized
melanic leucism.” These birds also have high levels of triglycerides in their
blood. Whether this is due to the lipid content or some other component of the
sunflower seed is unknown. High serum triglyceride levels are often associated
with liver ailments.
seeds, particularly their dust, can also be a problem for both parrots and their
owners. They produce an allergic response in sensitized people
. When a parrot has an allergy to them, the
clinical signs are struggling to defecate, flatulence or an inflamed cloaca.
Vitamin A. Vitamin A is toxic if you feed it in excess to your bird. Diets containing between 2,000 and 10,000 International Units (IU) are sufficient for a cockatiel, but when the experimenters fed 100,000 IU, the birds developed vitamin A toxicosis (57). Researchers have also noted that cockatiels have a different vocalization pattern when fed a diet high in Vitamin A. Those receiving a 100,000 IU daily dosage vocalized more frequently and for longer periods (58). Macaws and African grey parrots may be more sensitive to vitamin A excess (28). Rather than feed vitamin A itself, it is preferable to feed a pro-vitamin A such as β-carotene that the bird converts to vitamin A by its own metabolic processes (68). β-carotene is found in many vegetables and fruits.
Vitamin B3. See niacin.
Vitamin D3. Some think vitamin D3 toxicity causes mineralization of the kidney
Wheat. Some people, particularly those suffering from celiac disease are sensitive to the gluten and gliaden proteins found in wheat
Zucchini or courgette. The zucchini is a member of the curcubit family and occasionally they produce a toxin called a cucurbitacin. This is very rare in domestic zucchini, but if you notice that one is bitter or smells unpleasant, do not eat it. (Information from the New Zealand Food Saftey Authority.)
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