American Goldfinches are northern birds. They rarely show up before December. By the time they get here, they have molted their bright yellow breeding plumage and replaced it with feathers of a more somber hue. In essence, the American Goldfinches are no longer “gold.”
So why get excited about birds that are a drab olive-gray? Perhaps it is because what they lack in color they make up for in numbers. Goldfinches are social little birds that tend to move around in flocks. Sometimes the flocks will have hundreds of individuals! And as they roam around and feed, they “talk” to each other.
The sweet sounds of goldfinches is rendered as “to-WEE, to-WEE” rising on the “WEE.” They utter it as they come in to a feeder and as they fly away. In the air, goldfinches fly in a gently undulating pattern, giving the impression that the flock is a carousel, and the individual birds are the horses going up and down. And all the while they are calling to each other in happy musical sounds.
It is easy to like goldfinches. Many early ornithologists thought so too. Some, like Bradford Torrey (1885), even waxed rhapsodic. He wrote “Our American Goldfinch is the loveliest of birds. With his elegant song, and his more beautiful soul, he ought to be one of the most beloved of birds, if not one of the most famous, but he has never yet had half his desserts.”
Although Torrey meant that goldfinches were under-appreciated, his choice of words got me to thinking about what goldfinches eat. It turns out that their diet (breakfast, lunch and dinner, as well as dessert!) is almost exclusively seeds. Seeds of plants in the Compositae (sunflower family) are their favorites. These kinds of plants produce a seedhead with hundreds of small seeds. Think sunflower, but also thistles, asters and dandelions. A single seedhead provides lots of food in a compact package. Plus these kinds of plants tend to grow in large patches — perfect for feeding a flock.
Birdwatchers noticed the preference that goldfinches had for Compositae seeds. As bird-feeding began to catch on, they offered the birds sunflower seeds, but the gray-and-white striped sunflower seeds are just too large for the tiny bills of goldfinches. The smaller black oil sunflower seeds are more their size. And the tiny seeds of thistles are even better. Goldfinches are especially fond of thistle seeds.
However, thistles are spiny and not much fun to grow and harvest. A substitute was found in the niger oil-seed (Guizotia abbysinica) of Asia and Africa. This tiny black birdseed resembles thistle seed and is even higher in fat content and in calories. And, studies show that goldfinches prefer it over thistle seed. So, over 40 years ago, the rising birdseed industry began to import niger oil-seed as a wild bird food.
In 1982, many shipments of niger oil-seed were detained at the ports, because they were found to be contaminated with weed seeds. There was particular concern that seeds of the parasitic plant dodder would be accidentally imported along with niger. You have probably seen a local species of dodder. It looks like a yellow-orange net thrown over a field or pasture. Dodder is leafless and rootless. Its vines curl around green plants penetrating their tissues. Dodder then sucks all its nourishment from these host plants. Some species of dodder parasitize important crops, hence the concern.
The USDA-APHIS program went to work on the problem and, in 1988, a method of dry heat sterilization was found to destroy the dodder seeds without damaging the niger oil-seed’s nutritional content. The method also inhibits germination of most of the niger oil-seeds. This was determined to be a good thing since niger is not native to North America and probably should not be allowed to spread. Also, most people prefer that their bird seed does not sprout.
In 1998, the Wild Bird Feeding Industry changed the spelling of the name niger to “Nyjer” and trademarked it. This was to differentiate niger (now Nyjer) from thistle seed and to indicate that it was imported and heat sterilized. Interestingly, Nyjer seed is sometimes called “black gold” because of the extra expense incurred by treating and importing it.
Why pay up to five dollars a pound for specialty birdseed? Because it attracts a very special bird: the American Goldfinch. The goldfinch’s happy songs, sweet nature and bright yellow color (on its breeding grounds) make it a joy to have around. So paying more for Nyjer seed is worth it. But it makes sense to offer Nyjer seed in special feeders. The simplest is just a mesh sock with openings barely large enough for a Nyjer seed to be worked through them. The goldfinches seem to enjoy the activity; after all, winkling a seed out of a seedhead is what they were born to do.
Pre-eminent birder Roger Tory Peterson (1935) said, “The responsibilities of life seem to rest lightly on the Goldfinch’s sunny shoulders.” They do indeed seem to be high-spirited little birds, always happy and full of gaiety. It is nice to have them as our winter guests. So, go ahead and buy Nyjer seed and give the goldfinches their “just desserts.” They are Bee County’s avian winter Texans!