Mammal, no. Milk, yes. The European turtle-dove is one of the very few birds that produce "crop milk" to nourish their young. Subsisting entirely on grains, the turtle-dove feeds on farm fields as well as seeds growing in the wild. It winters in the southern parts of its range and summers in the north, taking different parts on its annual migrations. But with fewer birds completing the trip each year due to hunting, disease and rapidly declining habitat, they could use some more of the milk of human kindness.