They’re both Harris’s Hawks. Is it because one is a juvenile?
“Sorry. New users can only post one image…”
Many hawks have different plumage at different ages. Streaky chest plumage in this case indicates a sub-adult bird.
The more mature one is the first one?
Yes. We dont have Harris’s Hawks where I live so I am not sure how many years it takes for them to obtain their adult appearance.
Wheeler only lists juvenile and adult plumages for Harris’s Hawks. Pyle lists aging up to 5 years in some individuals, but by the SY/TY birds, it’s based mostly on retained juvenile plumage or how many generations of adult flight feathers are present. This much streaking suggests mostly juvenile plumage. (Without a date it’s hard to narrow it down further. Also, both Wheeler and Pyle are discussing birds in the US – if the shot’s from farther south (i.e. most of Harris’s range), then the molt timing, etc. is likely to be different.)