There is a common idea in bird feeding that a healthy diet should look impressive.
Seven or eight vegetables. Several fruits. Seeds. Sprouts. Herbs. Flowers. Nuts. Everything chopped together into one colourful bowl.
Social media has helped reinforce the idea that the more ingredients we can fit into a bird's bowl, the healthier that bowl must be.
But more variety does not automatically mean better nutrition.
As an avian veterinarian, I am often less interested in how many different foods are being offered than in a more practical question:
What is the bird actually eating?
Those can be two very different things.
Birds do not necessarily choose what is nutritionally best for them
One of the assumptions behind offering a very large variety of foods is that a parrot will select what its body needs.
The available evidence suggests that we should be careful with that assumption.
In a study involving adult Amazon parrots, the birds were offered a mixture of fresh produce, formulated food and seeds. The diets they consumed were deficient in calcium, sodium and iron and contained more fat than recommended. Importantly, the birds' food choices made several of the existing nutritional imbalances worse.1
They had access to multiple foods.
Their choices did not produce a more nutritionally balanced diet.
Earlier work involving African grey parrots demonstrated a similar problem. When the birds were offered seeds, oranges, vegetables and a nutritionally complete supplement, they selected predominantly from the seed component and consumed only a small proportion of the supplement. The resulting self-selected diet was deficient or marginal in multiple vitamins, minerals and amino acids.2
This is an important principle in avian nutrition:
Choice is not the same as nutritional balance.
A complicated bowl can encourage selective eating
Now consider a fresh-food bowl containing ten or fifteen ingredients.
From our perspective, it looks wonderfully diverse.
But the bird does not necessarily consume it as a complete meal.
It may select the sweeter fruit.
It may search for particular seeds.
It may consistently eat one vegetable and discard another.
It may carefully remove the foods it values and leave behind much of what we intended it to eat.
The more choices we provide, the more opportunity we may also provide for selective feeding.
This is why simply listing everything that goes into the bowl tells me surprisingly little about the bird's actual diet.
When I take a nutritional history, one of the most useful distinctions is between:
"What do you feed?"
and
"What does your bird actually eat?"
Those answers are often quite different.
Diversity in the wild occurs across place and time
It is also useful to consider what dietary diversity looks like in nature.
Parrots as a group consume a wide range of plant materials, and diets vary considerably between species and environments. Food availability is influenced by geography, season and what is available at a particular time.3
That does not mean an individual bird encounters or consumes a large collection of unrelated foods at every meal.
Certain foods may become abundant for a period. Others appear seasonally and then disappear.
Natural diversity can therefore occur across place and time.
It is not necessarily the same as combining as many ingredients as possible into every bowl.
Ingredient diversity and nutritional diversity are not the same thing
The number of ingredients also tells us very little about nutritional balance.
A bowl containing sunflower seeds, pumpkin seeds, peanuts, safflower, millet and dried maize contains several different foods.
It is certainly varied.
That does not make it balanced.
Similarly, apple, pear, grape, banana, mango and berries provide six different ingredients, but six fruits do not suddenly become a nutritionally complete diet because they have been mixed together.
Ingredient diversity and nutrient diversity are not the same thing.
What matters is the nutritional composition of the diet, the quantities actually consumed and the requirements of that particular species.
Complicated diets can make clinical investigation more difficult
There is another reason I prefer to understand clearly what a bird is eating.
Sometimes I need to investigate whether diet may be contributing to a clinical problem.
A bird may develop changes in its droppings, gastrointestinal function, body weight or another concern where dietary investigation becomes useful.
If the bird eats a relatively simple, clearly defined diet, I can look at individual components systematically.
Remove one food.
Observe the response.
Reintroduce it if appropriate.
Then consider another variable.
That gives me useful information.
Now imagine trying to do the same thing when the bird's daily mixture contains fifteen different vegetables, fruits, sprouts, herbs, flowers, seeds, nuts and supplements.
If several ingredients are removed and the bird improves, which change was relevant?
We may not know.
If another complicated mixture is introduced and the problem returns, identifying the relevant component becomes equally difficult.
The more variables we introduce, the harder it becomes to interpret what we are seeing.
For me, and for other avian veterinarians, that matters clinically.
Variety should have a purpose
None of this means that a bird should eat exactly the same food every day.
Appropriate dietary diversity can provide nutrients, different textures and useful opportunities for feeding and foraging behaviour.
But variety should have a reason.
For many companion parrots, an appropriate formulated food can provide a consistent nutritional foundation, with selected fresh foods offered alongside it.
Those fresh foods can be rotated.
We do not need eight vegetables in today's bowl simply because eight looks better than two.
Two or three appropriate foods today, followed by different appropriate foods later in the week, can provide meaningful dietary diversity while keeping the diet understandable.
The exact approach must also be species-specific.
A lorikeet, African grey parrot, budgerigar, pigeon and toucan have very different nutritional requirements.
There is no universal "healthy bird bowl" that is appropriate for all of them.
Variety can also come from presentation
We can also provide variety without continually increasing the ingredient list.
A suitable leafy vegetable can be placed in a bowl one day and clipped to the enclosure another day.
An appropriate vegetable can be grated, offered as a larger piece or incorporated into a foraging activity.
The bird now has a different feeding experience without necessarily changing the nutritional composition of the diet.
For an intelligent, active parrot, how food is obtained can be an important part of enrichment too.
A better way to think about dietary diversity
A bowl containing fifteen colourful ingredients may look impressive.
That does not tell me whether it is nutritionally appropriate.
It does not tell me what the bird actually eats.
It does not prevent selective feeding.
And if a dietary problem develops, it can make veterinary investigation considerably more difficult.
The research in parrots is particularly useful here. When given multiple dietary choices, they do not necessarily use those choices to produce a nutritionally balanced diet.1 2
So I would not measure the quality of a bird's diet by the number of ingredients in the bowl.
I would rather ask:
- Is the nutritional foundation appropriate for this species?
- What is the bird actually eating?
- Does each component have a nutritional or behavioural purpose?
- Can we clearly identify and adjust individual components if a problem develops?
If you are unsure what your bird is actually eating, keep a simple record for a few days of what you offer, what is eaten and what is consistently left behind.
That information can be very useful for me, or another avian veterinarian, when assessing the diet.
Dietary diversity has value.
But complexity should never be mistaken for quality.
References
- Brightsmith DJ. Nutritional levels of diets fed to captive Amazon parrots: does mixing seed, produce, and pellets provide a healthy diet? Journal of Avian Medicine and Surgery. 2012;26(3):149-160. doi:10.1647/2011-025R.1.
- Ullrey DE, Allen ME, Baer DJ. Formulated diets versus seed mixtures for psittacines. The Journal of Nutrition. 1991;121(11 Suppl). doi:10.1093/jn/121.suppl_11.S193.
- Koutsos EA, Matson KD, Klasing KC. Nutrition of birds in the order Psittaciformes: a review. Journal of Avian Medicine and Surgery. 2001;15(4):257-275. doi:10.1647/1082-6742(2001)015[0257]2.0.CO;2.