Sequence on Harris' hawks on nest in arms of saguaro cactus. LA of scientist Jim Dawson climbing up bird-watching hide. Harris' hawks wheeling in sky. Sequence on scientist Jim Dawson watching fom hide as Harris' hawks feed in nest. Sequence on Harris' hawk intruder attacking Harris' hawk nest, but is seen off after mid-air fight. Sequence on Harris' hawk returning to nest, being observed by scientist Jim Dawson in hide. (61)