I've never seen the film, is there any link to a digital copy? And I wonder if it used this archive footage of TR (www.theodorerooseveltcenter.org/Research/Dig...) or if it was original material filmed specifically for the Audubon Society?

AFAIK, that film has been completely lost. But I believe the clip you referenced was shot as part of the same trip, by Herbert Job. More footage of the trip is here: www.loc.gov/item/mp76000...