the common (English) name is the variable or red-backed hawk. They are a native Argentinian species (the range covers western and southern South America). A very nice species indeed.
I just checked ISIS and they appear to be extremely rare in zoos outside South America. The Disney Animal Kingdom is listed as having a female though.
In the UK they had a group of these at the Hawk Conservancy, which may have been deposited there by Customs [can't remember details]. I saw at least one trained & flying free as a demo bird. Very handsome indeed.
