Sparrows tend to be small, gray-brown birds with short tails and short, strong beaks. The differences between their species can be subtle. Sparrows are primarily seed-eaters, but they also eat small insects. A few species are scavengers in cities and, similar to gulls or pigeons, will happily eat essentially anything in small quantities. Like the finch, the sparrow's natural predators include jays, magpies, kestrels, hawks and owls.