I'd add that no wonder the White-browed Hawk often is confused, as some pretty bad illustrations of this species exists in several books, and it is generally infrequently seen. I might add that this exact species pair sometimes cause confusion even among people knowing the latter relatively well; see e.g this tread, where Fabio Raposo, one of the most knowledgeable ornithologists in Brazil, got it wrong (again you'd need to add www. first):
birdforum.net/showthread.php?t=69956
Rasmus Boegh
15-Mar-2008 10:28
Nice photo, but this is a juv. pale morph Short-tailed Hawk. The White-browed Hawk is superficially similar, although the colours of the bare parts are strikingly different. Here's a photo a White-browed for comparison (as I'm not logged in I can't post full URL's; add the usual www before the below address):