During the war years, Warner Bros. acquired a few foreign imports, which were re-edited into short subjects and given English narration and new music scores. Two of these were nature documentaries from the Soviet Union. I think, but am not sure, the first was "The Struggle For Life", which was completed in July 1943 (according to Roy Liebman's Vitaphone Catalogue) and copyrighted April 18, 1944. This second one may use footage from "Zakon Velikoi Lyubvi" (Great Romance) by Boris Dolin, but, again, I'm not certain and am open to any corrections.
Basically, a cute story about a baby red fox in a western Russian forest (with images of fallow deer, rabbits and other critters), the loss of his mother to a dog, a fight with a raven and the constant search for food. It closely resembles one of the later True Life Adventure films of Walt Disney, but instead of being filmed in Technicolor (like many Warner documentary shorts of the period), the camera work is soft-focus black & white... very dreamy and poetic. As mentioned in the previous review, the narration is a trifle "cute"; it resembles the Disney feature "Perri" in this regard.