Understanding the American Goldfinch in Florida
American Goldfinch (AMGO) reports sometimes begin to trickle in as early as September although there are August records of AMGO in Alachua County. These early birds always seem to be just passing through and rarely spend more than a day or two at the feeder.
Activity builds very slowly with only a few more reports coming in each October.
November is really the first month that we can hope to see AMGO in any substantial number. Most people reporting AMGO are inveterate feeder enthusiasts who have been working to build flocks of goldfinch for many years. Goldfinches also seem to prefer oil sunflower to anything else, even Nyjer, in the deep south this early in the season.
Activity levels build very slowly through December. Many feeder yards don't see flocks of more than a few goldfinches until January.
In February, when hardwood trees begin to bud out, goldfinches perform a false migration away from feeders to take advantage of the tender new growth in hardwood forests. As that tender foliage becomes more fibrous and stiffens, goldfinches return to feeders. At this point, they have also begun their molt into breeding plumage and they need to put on weight for migration. Those two new biological stresses increase the demand for quick energy and it's upon the return from false migration that feeder activity finally hits the fever pitch for which AMGO is so well known. This is also the time that they begin to prefer Nyjer to oil sunflower.