Safe, Toxic, & Unsafe Foods
Safe Foods in ModerationBecause seeds should not comprise more than 20% of what a finch consumes on a daily basis, a total of 80-100% of the diet should be provided "from the kitchen."6 Birds tend to eat to meet their energy requirements, meaning that they vary their intake based on the caloric density present in foods. If a food is calorie-rich, finches will eat a modest amount of it. On the other hand, finches will ingest a great deal of a lower-calorie diet in order to meet their energy needs. Fruits and vegetables tend to have high water content as well as many trace nutrients, yet they are low in calories. Because of this, they can supplement the nutrients that are likely to be low in seed while not diluting the diet with excess energy.6
"Safe" fruit and vegetable sources include: spinach, broccoli leaves and florets, carrot tops, grated carrot, celery leaves, parsley, endive, Brussels sprouts, cooked peas, alfalfa, kale, dandelion, turnip greens, romaine lettuce, beets, spirulina, kelp, applesauce, winter squash, yams, pumpkin, apricots, citrus, and bananas. Fruits and vegetables should always be fresh, prepared hygienically, and removed from the enclosure within 4 hours to prevent spoilage.5 Increased urine from eating increasingly watery foods may result in polyuria, which should not be confused with diarrhea.6
Because fruits and vegetables may not contain all of the nutrients that tend to be deficient in a typical seed mix, other sources are also available for supplementing your birds. These sources become particularly important during the breeding and molting seasons, as growing, egg-laying, and molting birds have a higher demand for nutrients such as protein. "Safe" animal protein sources include: canned tuna fish (packed in water), hard boiled or scrambled egg, cat and dog kibble, and grated cheese. Cheeses are safe to feed birds because they contain little or no lactose (a milk sugar which birds cannot digest); instead they extract the fat, protein, and some trace nutrients from the milk and leave the majority of the lactose in the whey.6 Amino acids can also be provided from balancing vegetable sources such as mature legumes. Whole grain products are also a valuable source of nutrients; they include: dry cereals, cooked cereals, crumbled whole wheat breads (stale or toasted). Also, commercial products such as monkey/primate biscuits are recommended. Biscuits made by ZuPreem and Science Diet are quality, and surplus quantities can be frozen until needed.
|If providing any of these foods, do so in moderation:
When Safe Foods May Become Unsafe5Any of the foods listed in this section that are normally considered safe may cause problems for a bird if fed in high quantities. Therefore, keep in mind that moderation is key. As long as any of the following foods are fed in minute quantities, your birds should not experience many (if any) problems.
Protease inhibitors inhibit digestive enzymes and, when present in high levels in the diet, may decrease the avian body's ability to digest proteins and lead to pancreatic hypertrophy. Although these enzyme inhibitors are present to a degree in all plants, significant levels are found in all legumes, corn, lettuce, oats, peas, peanuts, barley, beets, buckwheat, wheat, rice, rye, turnips, sweet potatoes and potatoes (in VERY high amounts).5 Luckily protease inhibitors are readily inactivated by cooking,5 so if any of the above-listed food sources are going to constitute a major part of your birds' diet, you should cook them first.
Acorns, lettuce, carrots, rape seed, grape seeds, bananas, spinach, onions, milo, grapes, and raisins have high levels of tannins. (Rhubarb, tea, coffee, and chocolate also contain high levels of tannins but these foods should never be fed to birds anyway as they may be harmful or toxic). Tannins can inhibit digestive enzymes, bind protein, and reduce the bioavailability of vitamin B12 and iron.5 Additionally, at high levels, tannins can cause epithelium and liver damage.5 Tannins (tannic acids) are the chemicals that are responsible for the normal browning of fruits and vegetables that have been bruised or cut. If feeding any of the above-listed "safe" foods that contain tannic acid, only feed them in moderation.
Oxalate (oxalic acid) is an organic acid makes calcium and other trace minerals unavailable to birds because it binds them.5 Lower levels of oxalate can cause reduced growth, kidney stones, and poor bone mineralization.5 Peas, beets, beet greens, lettuce, turnips, carrots, and berries have lower levels of oxalates; high levels of oxalates can cause diarrhea, poor blood clotting, vomiting and convulsions.5 Very high levels are found in spinach (tea also contains very high levels of oxalate, but it should not be fed to birds due to its caffeine content).
The complex of phosphoric acid and sugar is called phytate or phytic acid. This complex effectively forms a heterocyclic ring with metal atoms (minerals such as iron, zinc, and calcium), making the minerals unavailable.5 Phytates are found in nuts, cereal grains (germ and bran), and legumes. Phytic acid is also present in green beans, berries, carrots, broccoli, potatoes, and sweet potatoes, but at lower levels.
Other various inhibitors are present in a wide variety of food stuffs. Briefly, they include: amylase inhibitor (in wheat, rye, sorghum, beans), plasmin inhibitor which inhibits blood clotting5 (in some beans), cholinesterase inhibitors (in carrots, cabbage, asparagus, broccoli, celery, radishes, raspberries, strawberries, oranges, pumpkin, peppers, tomatoes, turnips, apples, eggplant, and especially potatoes), and kallikrein inhibitor which reduces antibody formation5 (in potatoes).
Thiaminase destroys thiamin;5 it is in raw fish, red cabbage, beets, Brussels sprouts, and berries, and is produced by some microorganisms that can inhabit that GI tract. Flax seed (and therefore linseed meal) should not be fed in high quantities because a compound present in it may inhibit pyridoxine (vitamin B6).5 Diarrhea and vomiting can be the result of a bird consuming high amounts of saponins5 which are present in alfalfa, spinach, soy beans, broccoli, asparagus, apples, eggplant, and potatoes. Lastly, goitrogens have anti-thyroid effects;5 they are present in soybean, peanuts, pine nuts, all of the brassica family (turnips, rutabaga, broccoli, Brussels sprouts, cabbage, kohlrabi, mustard, cauliflower, kale), and somewhat occur in carrots, peaches, strawberries, pears, radishes, and millet.
Toxic & Harmful FoodsNever feed any of the following to any of your birds:
- Moldy foods (possibility of mycotoxins, nutrient degradation)5
- Rhubarb and the house plant dieffenbachia (contain potentially toxic levels of oxalate)5
- Castor beans and black beans (contain plant toxins that cause kidney, liver, GI tract epithelium, and heart damage, as well as red blood cell agglutination and cell mitosis interference)5
- Avocado (some species are toxic to some birds, especially to canaries)6,7
- Raw egg (the avidin in it inhibits biotin)
- Poultry feeds (chick starter, chicken scratch, etc. grow large amounts of Pseudomonas, E. coli, & Klebsiella)2
- Stimulants (such as coffee, tea, or other caffeinated beverages)6
- Raw milk and raw milk products (e.g. dried skim milk [50% lactose], dried whey [70% lactose]), uncultured milk products.6 Because they contain significant amounts of lactose (a specific product of mammals), and because birds which have been tested cannot digest lactose, birds suffer from diarrhea when the diet reaches a level of 10-30% lactose on a dry weight basis.6 Milk products containing lactose should be avoided in favor of other sources that can more safely offer the missing nutrients you seek to supplement.