From personal experience and a great deal of research, I wrote the article I have included below for one of my parrot-related websites, the Elite Parrots Club. Lettuce is NOT deadly to any parrot, but iceberg lettuce can cause problems because it is nothing but watter. Here's a large section of the article and I hope you enjoy reading it.
[b:987914d16e]Seven Foods That Are Deadly To Your Parrot[/b:987914d16e]
When parrots were first keep as pets, people thought they only lived a short time. This was in part because most of the soft billed wild birds only live a few years but also because the parrots they kept die within 10 years or so. This was because the diet these parrots were being fed did not supply the necessary nutrients and the birds basically starved to death very, very slowly. Some succumbed to illness but this was in large part due to the fact that they were malnourished and their bodies couldn't fight the disease.
Today we know that many of the large parrots can live to be over 100 years of age and even budgies and cockatiels can live to be 20 or more. This is because we now know what to feed our parrots and what to avoid letting them eat.
There are lots of good things to feed your parrot, but there are a few things that you might offer that can kill your beloved feathered friend. The reasons may differ but the results are the same: death.
[b:987914d16e]Foods You Must NEVER Feed You Parrot[/b:987914d16e]
There are only a few things that can actually kill your parrot as far as human food goes. These are:
• Avocado
• Chocolate
• Alcohol
• Pits of any fruit
• Raw or undercooked meat
• Uncooked eggs
• Any food that may have mold or may have spoiled
(including seeds)
As you can see, this is a very short list.
[b:987914d16e]Foods You Should Limit[/b:987914d16e]
This list is a lot longer and contains people foods that won't kill your parrot quickly. However, over time, these foods will be detrimental to its health. These foods fall into 3 main categories. Some foods may fall in to several or even all of these categories:
[i:987914d16e]Foods High In Fat[/i:987914d16e]
Any food that has a high fat content should be limited. This doesn't mean that you parrot can't have a taste of these foods occasionally. Think of feeding your parrot as if you were feeding a three year old child. You would let a child have a few potato chips even though they are high in fat and salt, but you would limit the quantity. If you want to let your parrot have a bite of a single potato chip once in a while, there is nothing wrong with this very, very limited quantity. Everything in moderation is the practice to be followed for this list – very small amounts if what moderation means here.
Examples of these foods are: Potato chips, Vegetables with butter, Fried foods, Cream, iced, whipped or liquid, cake icing, fatty meat, butter sauces, cream soups
[i:987914d16e]Foods High In Salt[/i:987914d16e]
Too much salt isn't good for people or birds. Of course, since parrots are so much smaller, a little bit goes a long way. Some foods can simply be taken out of the food preparation cycle before salt is added to allow the parrot to enjoy a safe serving. Many foods can be found in unsalted versions that can safely be shared with you parrot. For example, unsalted nuts are fine but eating a lot of salted nuts is not good for your feathered kid.
Some of the foods in this category are: potato chips, corn chips, salted nuts, salted vegetables or meats, prepared foods such as microwave entrees that list high sodium content, salted popcorn, bacon, ham and other cured meats
[i:987914d16e]Foods High in Sugar[/i:987914d16e]
Parrots can become little junk food junkies if allowed. They seem to love sweets and will insist on having a taste. Most foods with sugar are perfectly safe to allow the parrot to have a very small bite or even two, but limit the quantities to a very small amount and do so rarely. Examples of these foods include: cake, cookies, candy, sweetened juices, other sweetened drinks, cereal that is high in sugar, ice cream.
[i:987914d16e]Everything Else[/i:987914d16e]
Everything else that you eat, you can and should share with your parrot. The more different foods your bird eats, the better its health will be, the more vibrant the feather colors and the happier you'll be. However, use some common sense about feeding people food to parrots.
Fruits and vegetables are very good additions to the diet, preferably raw but if you parrot prefers some things cooked, that is better than not eating the food at all. Eggs, cheese, pasta, rice, potatoes (other than potato chips or French fries), pizza, noodles, very small amounts of meat or fish and other people foods are great for you parrot. Limit the amount of meat to very small amounts because in the wild, parrots do not get a lot of meat-type protein. Some parrots LOVE a bone with bits of meat left on it to chew on and will even eat the marrow out of the bone which is quite health as long as you remove the bone before it has an opportunity to spoil.
Of course, fruits and vegetables are the best for the parrots and for us. But variety is the spice of life and everyone wants variety including your parrot.