seems like you would need something to detect individuals, and then you would then need something to classify each detected individual. Microsoft has this thing (https://github.com/microsoft/CameraTraps/blob/master/megadetector.md) that might help with the first part, but i bet you would need to design your own way of addressing the second part. so you could train an AI to identify species of interest, or you could just do some sort of simple color analysis maybe. (Microsoft does actually have a species classification model available: https://github.com/Microsoft/SpeciesClassification, but i don’t know if that model has been trained on your species of interest. you could also just use their framework on your own dataset, or do something on else your own. i bet there are other things available out there, not just stuff developed by Microsoft.)
iNaturalist featured something about shedding mountain goats back in the day (https://www.inaturalist.org/blog/16807-mountain-goat-molts-inat-photos-and-climate-change), and there was also a thread about someone’s winter break project analyzing maple leaf color (https://forum.inaturalist.org/t/analyzing-red-maple-leaf-color-in-10-950-inaturalist-observations/9376). these things seem somewhat similar to what you’re describing. so you might be able to reach out to such folks to get more specific advice, if others don’t provide better answers in this thread. or maybe a quick trip or e-mail to your local university might also get you some quick answers to your question (and possibly even some help with your effort)…