I spent the last 8 days staying at the Tropical Regeneration project headquarters (see https://www.tropicalregeneration.org/ ) where a family of Passerini's Tanagers was busy in the bushed near the back porch where I loved to hang out. It took this visiting birder a while to figure out that all of these birds were the same species. Check out these photos.

Adult Male. Fortunately this one was easy. The only similar species is not present in the area of Costa Rica I was visiting, so I had little trouble with him.

With the male there too it was not too hard to ID the adult female, or juvenile? of the same species.

Most fun though was this molting male. I deduced that it is a male born the year prior, and now undergoing its first full molt. You can tell it's not a juvenile by the extensive wear in the flight feathers that are yet to molt. Look at the very ragged tail feather tips and the nearly completely worn off coverts of the tail feathers. A juvenile undergoing a molt from juvenile into its first basic plumage shortly after fledging would have fresh flight feathers that it will keep until the next summer. I don't think it is an adult male in molt because of the other adult males in bright plumage, though I could be wrong in this deduction. Molt is a lot of fun to begin to understand, and you'll see me post on it from time to time.

Enjoy. Good birding. Steem on!