Goldfinches in the Garden

We have Goldfinches in our garden and my wife isn’t happy. Sure, these little guys are colorful and cute but it is their diet that is causing problems around here.

When I was growing up we used to call these birds Wild Canaries but at some point the name was either changed or we just found out that officially they are American Goldfinches. They are a migratory bird further north but here in Tennessee they stay year round. Goldfinches like humans because we clear forests into fields and gardens and that is where these birds thrive.

The male goldfinches are bright yellow with black wings and a black cap in the summer breeding season. The rest of the year they are drab olive very similar to the females.

Goldfinches are primarily seed eaters. They eat seeds from thistle, teasel, dandelion, ragweed, and sunflowers. They especially like the store-bought “thistle” seed called nyjer or niger (pronounced ni-jer). This expensive tiny black seed isn’t native thistle, but rather it is imported mostly from Ethiopia and it is sterilized before being imported so it doesn’t become an invasive plant like kudzu has become. There are even special feeders for this seed for goldfinches.

Goldfinches are one of the latest birds to nest each summer…usually waiting until July before starting a family. Their cup nest is so tightly woven and lined that it often can hold water without leaking. Goldfinches are usually monogamous, but supposedly every once in a while, a female will leave as soon as the eggs hatch and let the male feed and raise the babies. Meanwhile that female flies off to find a new boyfriend and start another family. I think there are names for females like that; I just can’t print them in a family newspaper.

There is an interesting fact about their seed diet that protects goldfinches. As you may know, cowbirds are brood parasites. That means the cowbirds don’t build a nest; they just lay one egg each in other birds’ nests and let the other birds raise the cowbird baby. The young cowbird often hatches first and, because it is bigger, it gets all the food from the foster parents to the detriment of the real babies. Well, even though cowbird eggs are found in as many as 10% of goldfinch nests, the cowbirds never make it to maturity in a goldfinch nest. The reason is because cowbirds can’t make it strictly on a diet of pre-digested seeds…they need meat, such as insects, to grow. While goldfinches do eat some insects, they don’t supply enough to meet the protein needs of the cowbirds.

The reason that goldfinches are not on my wife’s favorite birds list is because they tear apart our zinnias and coneflowers to eat the seeds. They even perch on the little rubber snake in the flower box that was put there to scare them away. We have a flower box with many stems with empty seed heads and no petals. But there are enough flowers to still look O.K. and I guess the little guys need to eat too. I’ll feed them nyjer seed again in the winter to keep them around because they are fun to watch and they rate a 9.9 for “cute” on my Olympic rating system.