Answer: He returns to the man village willingly.
Bagheera has almost given up hope of returning Mowgli to the man village, when by chance Mowgli hears an unfamiliar sound. Following it, he and his friends see a sight such as the man cub has never seen before. When he asks in awe what it is, the worldly wise Baloo replies, "Forget about those, they ain't nothin' but trouble!" He tries valiantly to forestall the inevitable, but Mowgli wants a closer look.
All the time the girl, sung by Darleen Carr, is filling her water jar. In his eagerness to get a closer look, Mowgli falls out of the tree he had climbed, splashing into the water and making the girl laugh. He swims to shore but, as Baloo says, he's hooked. She starts up the path and, in a lovely piece of business, drops the jar. Mowgli leaps to retrieve it and, with a last look back at his grieving friends, he follows her into her house.
Richard and Robert Sherman, who wrote the music for several Disney films including "Mary Poppins" as well as other movies including "Chitty Chitty Bang! Bang!" felt that songs should grow organically from the story and, where possible, forward the action. Their score for "The Jungle Book" (which incorporates Terry Gilkyson's "Bare Necessities) does this. But in a sense it does more. The song that the unnamed young girl sings at the end merely puts words to the theme that runs through the entire film, what one comes unconsciously to think of as "Mowgli's Theme". So, when he hears her sing, it seems totally right that he is drawn to her and, in the end, follows her.
Baloo is heartbroken to lose his man cub. Though Bagheera is sad too, he knows it is for the best and things are now back as they should be. The film fades with the friends walking into the jungle sunset, singing "Bare Necessities".