Do Finches Need Grit?
This is a question that comes up frequently and the simple answer is beneath the feet of the wild Owl and Longtail finch in the photograph above.
The photo was taken in northwest Australia, and at least for Australian finches (and I would think for most wild finches), grit is everywhere all the time in both soluble and non-soluble forms (limestone, crustaceans, sand, etc). The photo I don't have is of the several hundred acre burn just a couple of miles from where I took this photo. Charcoal is never very far away from finches living in the top half of Australia and they usually have easy access to it.
Soluble calcium grit is the best calcium supplement you can offer your finches as it allows them to regulate their calcium intake naturally. Non-soluble grit allows your finches to consume grit when they feel the need for grit without consuming calcium. Parent birds use grit to help grind the food they are feeding nestlings in addition to providing calcium for the nestlings' development and to replenish calcium in the hen's body lost through the production of eggs. Finches will also consume grit throughout the year to a lesser extent as a dietary supplement. A good grit mix is about 90% soluble (egg shell, oyster shell, etc), 5% non-soluble (sand), and 5% charcoal (they have access to burned out stumps that stand for years), and certainly in the case of Australian finches you can offer all of the above ingredients ad-hoc continuously.
Fixed doses of calcium supplements in water or foods don't work as the bird has to eat or drink more or less of the food or water to regulate the amount of calcium they are getting. How much calcium does a hen that lays 4 eggs need vs. a hen that lays 6 eggs? A fixed supplement dose of calcium can't be right for both! And does she have to drink more water or eat more of a certain food to get it? This can lead to gorging on food or a calcium deficiency/overdose if you guess wrong on the water supplement dosage. Excess calcium accumulates in the liver and can lead to liver damage. Too little calcium in the diet can lead to a number of health problems. Calcium supplements must be free choice. Many foods have natural levels of calcium, so the answer is a high quality natural diet with a cup of soluble/non-soluble grit on the side to let the birds decide.
The feeding of grit seems to be a point of controversy among veterinarians also, with some recommending it and others opposed to it. The argument against offering grit is that your finches may gorge on it which can lead to crop impaction. Gorging can occur if the overall diet is incorrect or if the bird is sick. So offering a good calcium grit can also serve as an indicator of a poor diet or poor health. If you see continuous gorging of grit outside of the breeding season this serves as an excellent warning system of other underlying problems...problems you may not otherwise know exist. So the advice of not offering a soluble/non-soluble grit is advice designed to protect your birds from behavior related to an already deficient diet or health problem, not advice for the proper maintenance of birds on a balanced diet that are in good health. Grit is simply part of a well balanced nutrition program for species that consume grit in the wild, and the science of finch nutrition has reached the point that offering grit is quite appropriate and in fact an optimum practice.
Bill
http://www.FabulousFinch.com
http://www.NigerThistle.com
