Do Parrots and Other Pet Birds Need Grit?

It once was common knowledge: pet birds need grit. Cages came with "grit cups" and no pet bird supply list was complete without a box of grit. Then, as it sometimes does, common knowledge changed. Veterinarians reported birds brought in to their offices, sometimes alive but often dead, with impacted crops, so full of grit the birds could no longer eat or digest their food. Pet bird authors and experts caught on, and advised no more grit. It could be deadly!

Who's right? Who's wrong? Do birds need grit? Can it kill? The answer, as most answers to such divided issues are, is somewhere in the middle.

Birds, of course, don't have teeth. Although parrots and some other birds "pre-process" their food by chewing, food is further broken down and processed in the bird's ventriculus -- popularly known as the gizzard. The ventriculus is a specialized section of the gastrointestinal tract, tough and muscular enough to grind up food. Small, indigestible items -- grit -- remain in the ventriculus, and further aid in the grinding and processing of the food. The finer the food is ground, the more readily it will be digested, and the more nutritional value a bird will gain from it.

That's how grit is used, but it doesn't answer the question, do birds need it?

Some birds almost certainly do. Many birds swallow their food whole, and when those foods include tough-to-digest items such as whole, unhulled seeds and grains, the ventriculus is simply not able to grind them down into a digestible form without the addition of grit. Among our captive birds, doves, pigeons, quail, pheasants, and chickens all require grit, especially if fed a diet including unhulled, unprocessed seeds or grains. The exceptions prove the rule -- chickens fed primarily processed chicken feed, for instance, don't absolutely require grit. If they're fed only unprocessed grains without grit, though, it can mean a slow death from starvation, no matter how much they eat.

Most bird experts agree with me on that. The real controversy begins on the question of whether birds who chew or hull their seeds before eating them need grit. This includes all of our most popular pet birds: finches, canaries, and all parrots from parakeets to macaws. Do these birds need grit? The answer seems to be no, they don't need it. Bird-keepers have kept, bred and raised all of these birds for years, even decades at a time without grit, and they remain healthy.

Yet, the story doesn't end there. Grit may not be necessary for most of our pet birds, but it could still be desirable. They may be capable of digesting their food without grit, but that doesn't mean it might not be easier for them to digest it with grit. There's no direct evidence for this, except for that offered by the birds themselves: most pet birds will seek out and ingest grit when it's available. When it's not available, many pet birds will eat other small, indigestible objects in the place of grit. This can be dangerous, because the objects they choose may be potentially toxic. Louise Bauck, DVM, and director of veterinary services for the Hagen Avian Research Institute, said, "We have seen a great variety of weird objects in gizzards -- watch parts, buttons, pushpins, feeding tubes -- some of which did not do very much harm, and some that did."

So should we feed our pet birds grit? Dr. Bauck adds, "In my opinion this is a good idea, if only to keep him from looking for more dangerous objects to consume."

I tend to agree, for that reason and another: wild parrots of many species have been observed eating grit, and seem to preferentially seek it out at times. I have to go to another parrot expert for another quote, this time E.B. Cravens, long-time bird-keeper and author. "Truth is," he has said, "Field studies have shown that psittacines of all kinds do go to the ground and ingest grit for many reasons--they even feed it to the chicks in the nest. My breeder parrots, all of which have access to the ground, will begin to ingest soil and sand and crunchy substrate one to two weeks before the laying stage and continue to eat grit well through the first weeks of chick feeding."

E.B. Cravens aside, many pet bird experts, especially so-called "experts" online who repeat what they've been hearing for years, disagree. Grit is thought to almost unavoidably cause crop or ventricular impactions and death. Of course, impactions can only occur if a bird consumes an excessive amount of grit. The ventriculus requires only a very small amount of grit to function at its best, and normally birds only consume grit in these very small amounts. Birds who over-consume grit may have an underlying health problem which drives their craving. Dr. Bauck recommends grit not be fed to ill birds. Another theory is that birds may over-consume grit in order to gain trace minerals or other nutrients they're missing as a result of a seed-only or otherwise deficient diet. As a rule, healthy birds don't eat unhealthy amounts of grit. Still, the danger is there.

The easiest way to prevent overconsumption of grit is simply to feed very, very little of it. If grit isn't offered free-access, birds can't "binge" and cause impactions. E.B. Cravens again: "The addition of grit to the domestic parrot diet can be done very safely if one gives small salt and pepper amounts of clean bird grit to the diet once every two or three weeks." Dr. Bauck points out that grit can remain in the gizzard for anywhere from a few days to a few months, so a small amount every couple of weeks should be plenty, and completely safe.

So do parrots and other seed-hulling species need grit? No. Should we feed it, anyway? Maybe. I'll even say, "Probably." Parrots in the wild eat grit, and our pets often seek it out when it's not available. It's highly likely that it's useful to them in some way. And if offered in very small amounts, it's perfectly safe.

So having gone from "birds need grit," to "never feed pet birds grit," I hope to see common knowledge on the subject swing back around to a more comfortable, reasonable middle-ground. If fed properly, in small amounts, grit is not harmful, and may be helpful. I recommend it, just a little, to all your feathered friends.

Sources:
http://www.petpublishing.com/birdtimes/articles/grit.shtml
http://www.parrots.org/index.php/forumsandexperts/answers/ask_an_expert1/
http://eclectusparrots.net/grit.html