Feeding Behaviour.

House finches. April 8, 2025, Rondeau Provincial Park, Ontario, Canada. In the hedge in the yard a pair of house finches displaying courting behaviour with the male giving seeds to the female. Haemorhous mexicanus The red of a male House Finch comes from pigments contained in its food during molt (birds can’t make bright red or yellow colors directly). So the more pigment in the food, the redder the male. This is why people sometimes see orange or yellowish male House Finches. Females prefer to mate with the reddest male they can find, perhaps raising the chances they get a capable mate who can do his part in feeding the nestlings. House Finches feed their nestlings exclusively plant foods, a fairly rare occurrence in the bird world. Many birds that are vegetarians as adults still find animal foods to keep their fast-growing young supplied with protein.