Coots are generally thought to be omnivorous, but that is not the case with any specific individual coot. As wild animals, coots will want to eat whatever they are familiar with. They are very suspicious of foods that they don't recognize. Fortunately, most wild birds will like the Cheez-It crackers, which will form a starting point in trying other foods. I believe that flocks of coots that forage together share the same skills, and taste for food. If you can train one coot in a group of coots to eat something, it is more likely the others will try it too. It is important to understand that every coot is an individual, and each one may have greatly different preferences in food.
In 2004, I started growing meal worms as a diet supplement for the coot. Most birds and reptiles like the worms. Worms are grown in oat bran with a slice of apple or other fruit thrown in for moisture. After four weeks, my worms changed to cocoons and hatched out into beetles that breed and lay eggs. When the beetles are done laying eggs, they are supposed to die. By the middle of February, dozens of pin size worms have hatched. I start transferring these worms to another enclosure (as soon as I can see them) to prevent cannibalism.
In July 2005, I have become tired of the worms that seem to be growing smaller, eating each other, and attracting flies. I dumped them in the trash and now buy meal worms from the pet shop. I obtained some "super worms" and found that the coots wouldn't eat them. The super worms also stink.
Ornithological journals say that corn is high in carbohydrates and makes a good high energy diet. The coot now seems to prefer corn to worms.
In fact, most migratory coots I encounter here will not eat corn. It seems odd to me to hear about bulk feeding coots with corn. Even migratory coots that have been well trained by hand feeding will not eat it. When placed in their beaks, they simply drop it and continue to look up at me to be fed.
I wanted to try commercial poultry feed for the coots to see if I could find a more nutritious diet. Six samples were obtained from a feed store. The coot knew what he had to do, and obediently tried them all. It seemed like he might tolerate the Purina laying mash, and showed some interest in the wild bird feed (probably because of the dried corn). The coots really didn't like any of it, and probably only captive animals would eat it. This feed is relatively cheap at 40 cents a pound, but if you wouldn't eat it, wild coots probably wouldn't eat it either.
In 2002, I would put out an open bag of bulk rolled oats and a coffee cup with water. The coot could come and go, and eat whenever he wanted, and not make a mess.
Blackbirds were beginning to be a problem, eating the coot's food and hanging around in large numbers. To thwart the blackbirds, I hid the food under the bath towels that are always around the boat. I showed Beaky where I hid his food and Thirty minutes later, but never before, he was busy wadding up all the towels he could find searching for food. A week later, the blackbirds began looking under the towel also.
Since he got the idea that the food is hidden, he will continue to turn everything over until he finds what he wants, or throws everything over the side into the bay. Cups and towels can often be recovered at low tide.
By 2006 it became obvious that playing with the coot up on the boat was very dangerous. A hawk attack proved that I could not protect the coot from everything, and if he ever fell inside the boat's cockpit while I was away and could not get out, he would be an easy meal for any predator. Since then, the coots stay on the dock.