As a new joiner to the topic, have we considered the option of adding more annotations than just adult, juvenile or egg on avian taxa? I’ll give three examples. My thing is raptors and I hate placing annotations on Red-tailed Hawks that are 1st Year birds. A bit of background, a 1st Year RTHA is a either (1) a juvenile after between January 1st and March or (2) An adult-plumage bird with aspects of juvenile, namely retained remiges and rectrices, and light-colored eyes. Perhaps immature would be a more appropriate term to use and would also cover 1st Fall individuals, or hawks that starts obtaining adult feathers in fall instead of spring. Other species like Swainson’s Hawks also have a 1st Year/Immature plumage and a 2nd Year plumage.
Example two, we know large species like Golden and Bald Eagles take 5 years to mature and each year they acquire a plumage that’s different from the others. So I think perhaps a chance to label a Bald Eagle 2nd or 4th Year would be helpful but once again, 2nd-4th Years can fall under the category immature.
Lastly, the White-crowned Sparrow. It has a juvenile plumage that is very streaky for summer but once migration starts, they molt into another plumage that most observers are used to seeing in the US. There are two distinct plumages before adult in that species. Once again, it can fall under immature.
All the examples I described have multiple plumages before adults but they can all fall under “immature” and I think an annotation for that would be awesome.