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Grit, Calcium, Salt and Water – Wild Bird Feeding “Extras” – Part 1

While any food provided to wild birds is beneficial, there are a few items that are very important to their health, especially in the winter, but which are often over-looked by well-meaning avian enthusiasts.


Pigeons, Doves and many other birds must swallow small stones, sand and similar materials (“grit”) in order to break down seed coats and other foods before digestion can take place.  Grit is often in short supply during the winter, being either covered with snow or frozen to the ground (in NYC, I’ve observed English sparrows on buildings, pecking at gravel within brick mortar).

You can help winter birds along by providing pet bird gravel, sand and oyster shell (available at garden supply shops) in snow-free locations.  It is best to keep grit separated from food, as it will be used slowly and may become contaminated with feces if it lies out too long.


Calcium is especially important as winter turns to spring, since female birds utilize this mineral to produce egg shells.  However, insects, the main source of calcium for many species, are often scarce at this time of the year.  Our Wild Bird Mealworms will be most appreciated by nearly every bird that visits your feeder.  You can also supply calcium by mixing oyster shell and ground-up eggshells into your wild bird food.

Food and Shelter

Of course, food and shelter are important concerns year-round.  Please be sure to check out our extensive line of bird and wildlife foods, houses and feeders.

Next time we’ll cover a few additional winter-feeding essentials.


Further Reading

Winter is a great time to try your luck at hand-feeding wild birds.  Please see Hand Taming Wild Birds for more details.

Woodpeckers, chickadees and other acrobatic birds will put on quite a show if given the chance – please check out Feeding Woodpeckers and Other Avian Athletes for details.


Grit and Gizzards – how birds digest seeds


Seed-eating birds utilize a unique process in order to digest their hard-shelled diets. Digestive enzymes cannot penetrate the seed shells (for doves and other species that swallow the shells) nor, in some cases, the inner seed covering (species that crack seeds before eating). To get around this, birds have evolved a muscular organ known as the gizzard, or ventriculus, to help grind their food into smaller pieces.

Seed-eating and certain other birds increase the gizzard’s effectiveness by swallowing stones and gravel, which are stored and act as grinding surfaces. These stones are periodically regurgitated or passed in the feces, possibly to prevent their becoming smooth and, consequently, less effective. Be sure to always have grit available to your seed-eating birds, prod or they will not be able to derive adequate nutrition from even a well-planned diet. Bits of cuttlebone also help to grind seeds, but only temporarily.

Pigeons swallow huge amounts of gravel, as they consume their seeds shell and all. While working with reptiles years ago at the Bronx Zoo, it was standard practice to trap pigeons for use as crocodile food (sorry, pigeon fanciers – I like pigeons too, but it was impossible to keep them out of certain exhibits, and they were implicated in the spread of diseases to the collection and staff). However, tests showed that the pigeons’ lead levels were incredibly high, due in part to ingesting the heavily-polluted Bronx gravel, and we ceased the practice (the pigeons were and remain fat and healthy none-the-less).

In the Bronx community where I grew up, “city” pigeons featured in the diets of people from several European countries. Elderly but quick-handed women tossed wet towels over pigeons as they came to feed on fire escapes (on bread put out by the same women, of course!) and knocked the squabs from nests with long bamboo canes. I never protested, despite my interest in all things avian, as their quick reflexes were just as likely to be used against annoying children as tasty pigeons! Well, that neighborhood is still home to some quite elderly people, so perhaps the lead-laced pigeons have not had their revenge!

A number of fishes and crocodilians have gizzards and utilize stones – more on that in the future.

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