The role of Jungle Jim was played by a few people, with Matt Crowley apparently holding the role the longest (Gerald Mohr played Jim for a few weeks). Jim Bradley was a big game hunter, but the series seldom featured him hunting big game; instead, Jim would be hired out by governments to use his wilderness skills to investigate strange goings-on around in jungle climes, usually in Asia. Accompanying Jim was Kolu (Juano Hernandez), an Indian guide-- though he spoke in the type of speech radio usually gave to American Indians.
The initial storyline where Jim investigates the "Bat Woman" cult, which proves to be led by the criminal Shanghai Lil (Franc Hale), is a pretty darn good adventure serial. Shanghai Lil would turn out to be an undercover good guy who would renounce her criminal past and accompanied Jim on many of his adventures - a sort-of Burma to his Pat Ryan. But to complicate matters, Jim also wound up with his female sidekick Kitty St. John, who would make Lil jealous.
After Pearl Harbor, the show rapidly changed as Jim started fighting German and Japanese foes; he joined the Marines and was sent back to the States to ferret out undercover foreign agents (because when your speciality is hunting and tracking in Asia, obviously your greatest usefulness in World War II is to hang around stateside as a secret agent). By spring of 1942, the show's format was radically reinvented as, instead of the show's accustomed rhythm of lengthy adventures, it tended to feature Jim battling enemy agents and wrapping it all up within his 15 minutes; there were still some continued adventures, but typically they fell into no more than 2-part stories. My suspicion is that the radio show had stopped adapting the comic strip around this time. This version of The Adventures of Jungle Jim is an interesting change to witness, but it's inferior to what came before.
Because there are no shows from 1943 available I don't know when the series changed, but by 1944 Jim and Kolu (a new actor playing Kolu) were back in Asia, going on guerrilla missions against the Japanese in Malaya, which makes a lot more sense for their particular skills. They led an "Allied" team with members hailing from India, Australia, the Soviet Union and China, which meant the actors portraying those characters could use a variety of dialects.
After the war, the series shifted back into what it had been before; Shanghai Lil returned and joined Jim and Kolu on globe-trotting adventures that seemed to be based around Latin America.
Although the show didn't like to credit anyone (including Alex Raymond!) recognizable voices include Gale Gordon (who'd previously been Flash Gordon), Hanley Stafford and Elliot Lewis. The show's theme was taken from the William Tell Overture (a different part of the Overture than that used on the Lone Ranger). Up to 1942 the theme was played with a band, then it shifted to an organ.
Alex Raymond left Jungle Jim and Flash Gordon in 1944; the strip continued with John Mayo and Paul Norris and even spawned a series of movies starring Johnny Weissmuller, but the comic strip, movies and radio show ended in 1954; Weissmuller kept going with a TV show that only lasted 1955-1956. As I noted yesterday, Flash Gordon has transcended his humble origins and enjoys occasional revivals; Raymond's Flash Gordon is considered one of the greatest comic strips of all time. Jungle Jim, by contrast, is a historical artifact; today, it's mostly brought up when discussing Flash Gordon, not for its own merits. Flash Gordon had the last laugh.
The Old-Time Radio Researchers Library has 526 episodes of The Adventures of Jungle Jim; it's pretty much complete up into 1942, then gets a little spottier in later years. A clear sign that this series needs more love is that the OTRR Library files are badly missorted and misidentified. You can view their files at this link.





