If you are feeding birds, you’ve probably seen a house finch.
The male birds are those sparrow-sized, grayish-brown birds with red on heads, shoulders and breast. Females lack the red but are streaked with brown on the belly and breast.
Eighty years ago, it would have been amazing to see one in New Jersey. Fifty years ago, it would have been a bird that New Jersey birders would go out of their way to see (we did).
If you look at a really old bird book, their range in the United States before 1940 was only in the Southwest, southern California and part of Oregon. Look at a current book, and you will see that it extends across the entire continent.
How did they get out of the Southwest? Well, during the late 1930s, thousands of them were shipped from California to pet dealers in the East, under the name “Hollywood finches.” This was illegal — you can’t do that with any of our native birds.
Acting on a tip from a bird lover, agents of Fish and Wildlife raided a pet dealer in Brooklyn in 1940. He presumably released his birds. Other dealers and owners would have learned about this and could have liberated birds they were holding. Our eastern birds are descended from these birds, and possibly just from a few dozen birds released by that one Brooklyn dealer.
All the old eastern records are from western Long Island, i.e., the New York City boroughs of Brooklyn and Queens.
The newly-free birds adapted well to our climate. They were aggressive and defended their nests. They readily found food in the urban environment and they kept other birds away from food sources.
They competed successfully with other native birds including purple finch and goldfinch, and with the non-native house sparrow. They bred and thrived, and by 1960 they were in New Jersey. By 1980, they had reached Ohio and the Carolinas. By 1990, they reached the Mississippi and 10 years later their eastern and western populations met.
House finches are almost exclusively vegetarian, feeding on berries and seeds including the very small seeds of such plants as dandelion and mugwort. They forage both on the ground and in vegetation and they come readily to bird feeders.
They are one of the few native birds that feed their young exclusively on plant material, which incidentally makes them almost immune to parasitism by cowbirds. Cowbird fledglings can’t survive on a vegetarian diet.
House finch nests are cup-shaped and made of small twigs and debris, lined with finer material, and are built by the female bird alone. They are placed in cavities, including crevices in buildings, spaces behind signs, and the other nooks and crannies typical of built-up areas.
Two or more broods are raised each year, with usually four young in each brood.
For information about the Gloucester County Nature Club, see gcnatureclub.org/