​Species: Common Yellowthroat
Most recent capture date: 4/16/2023
Age: around ten months old
​Sex: Male

Notes: This time of year we have several types of Common Yellowthroats at CCFS. Some are locals who breed here, while others are just passing through on their way to breeding grounds elsewhere. A good clue to identify which is which is how fat they are: a very fat bird is probably migrating, not staying here. (Birds don’t generally bother to put on a lot of fat unless they are migrating.) This fellow was the fattest bird I have ever seen, so he is almost certainly just passing through.

(You might say “Well I’ve seen fatter birds than that!” but this isn’t the kind of visible-from-afar volume that results from the bird fluffing up their feathers; this is physical fat stores, which you can only see by looking beneath the feathers at the bird’s skin.)