This tiny black seed has a high oil content and is very appealing to American Goldfinches and other finches. ... The seed that is fed to birds commonly called "thistle" is actually imported from India, Ethiopia, Myanmar, and Nepal. It is heat-sterilized when it is imported into this country so it will not germinate and therefore will not grow (weeds) under your feeder. (J.J. Cardinal's Wild Bird & Nature Store)For the first couple of weeks, the feeder was mobbed with House Finches. Finally the little yellow birds showed up - one or two at first, but then more and more. They are Lesser Goldfinches. They've been feeding from our sock feeder and later our metal thistle feeder since mid-May. I was apprehensive at first that they would be overwhelmed and chased away by the much larger House Finches, but they hold their own quite well.They ate the flower heads from our newly planted Desert Marigolds, and more recently have begun to feed on the seeds of a Butterfly Bush.
When I go out to fill the feeders, they fly up into the mesquite tree above my head, but don't go very far away.According to my Peterson Field Guide, they are resident in southern Arizona year-round. I wonder if they'll frequent our patio all year.