Contrary to popular belief, Walt Disney was involved in the development of the film, which began in 1962. Walt disliked the idea of a faithful adaptation of Margery Sharp's first "Miss Bianca" novel in which the protagonists set off to a rescue a Norwegian poet from a gloomy prison; he instead suggested it be changed to the rescue of a polar bear named Willie. Following Walt's death, Sharp's second novel was chosen as the primary source for adaptation.
This is the very first Disney animated classic film to feature a small prologue prior to the start of the opening credits; the credits are thus attached into the storyline as they are shown over images describing the journey of Penny's bottle. Madame Medusa is also the first Disney villain to affect the flow of the story from the very start of the film.
Early in the film's development, Cruella DeVil from 101 Dalmatians (1961) was to be the villain instead of Madame Medusa. There are similarities between the two characters, notably during the reckless driving scenes where the women are seen through their car's windshields. Veteran Academy Award-winning American actress Geraldine Page voiced her character of Madame Medusa with a British accent in order to add the element of sophistication that is stereotypically associated with it. Further connections can be made to the early suggestion of reusing the character of Cruella DeVil (who also spoke with a British accent), as well as to reflect the primary inspiration for the character of Madame Medusa, which was the Diamond Dutchess in Margery Sharp's "Miss Bianca" (1962). Early sketches of Madame Medusa showed clear similarities to Garth Williams's design of the Diamond Dutchess in the original novel, "Miss Bianca". Brutus and Nero are based on the two bloodhounds, Torment and Tyrant. The character of Mr. Snoops is a retouched "Mandrake" from "Miss Bianca". One of Miss Bianca's talents in the original novels was being able to charm dangerous animals like cats and dogs (she being a mouse), that element was added to the film in the form of the wise cat, Rufus. Mr. Snoops is a caricature of film historian John Culhane, who made regular visits to the Disney studio during production and was nicknamed "Mr. Snoops" by the animators. The Rescue Aid Society was originally the "Prisoners' Aid Society", just as it was in the original Margery Sharp novels.
Bernard (Bob Newhart) complains several times that he hates flying. One of Newhart's comedy routines was called, "The Mrs. Grace L. Ferguson Airline (And Storm Door Company)", wherein he explains why he hates to fly.
The last film participation for animator-director John Lounsbery. He died nearly a year-and-a-half before the film's release. His co-directorial duties were eventually passed on to animator Art Stevens.
The name of the cave where Penny must locate the Devil's Eye, the world's largest diamond, is never mentioned by a character in the movie, but according to the map that Madame Medusa is looking at, the name of the place is the "Black Bayou".
Early in story development, Bernard and Bianca were supposed to be rescuing a poet much older than Penny from a gloomy prison. This idea was scrapped since the directors decided that it was just not working.
Bernard and Miss Bianca were supposed to go to a mouse supply room in the International Rescue Aid Society Headquarters. In here, they were supposed to have bins full of items Bernard and Miss Bianca would need on their journey. Once they were packed Rescue Aid would then send them off. Ken Anderson drew conceptual art of this storage room, what was inside of it, etc. This idea never made it past this stage.
In one scene, Bernard, Miss Bianca, and Penny are in the cave trying to retrieve the Devil's Eye out of the skull of a dead man. Ken Anderson's Multiple Choice Layouts displayed Miss Bianca taking pictures of the skull and Bernard inside the cave.
The first of the Disney classics to improve the Xerography process considerably. While its xeroxed predecessors had a much sketchier look and used a black toner, this movie used a medium-gray toner for a softer-looking "line" (the cel artists added some color inks, too, but Xerography handled most of the inking). The Rescuers was also the first one where purple outlines (for Miss Bianca) was used (color-xerography). Later, other colors were developed.
CASTLE THUNDER: Heard over the Buena Vista opening logo (on the DVD version, the thunderclap is heard over the 1985 Walt Disney Pictures opening logo), and then again at the first sight of the old riverboat. All other times lightning flashes in the movie, it is silent except for music; the dialogue and sound effects have been muted.
Considered by many of the film's producers, critics, and audiences to be the film that proved that Walt Disney Productions' animation department could survive after the death of Walt Disney. The film was the company's first major success since The Jungle Book (1967) and last until The Little Mermaid (1989). The Rescuers (1977) also out-grossed strong competition such as Star Wars: Episode IV - A New Hope (1977) in many European countries including France and Germany.
In the scene where Penny is seen carrying Rufus the cat off to supper, Penny grabs Rufus and uncomfortably carries him off in her arms, pushing him up with her knee as he begins to slip. Ollie Johnston, who animated this scene, explained that he did this in order to show the tender affection between Penny and Rufus, by having the cat be too fond of Penny to complain, since it would have been easier for Penny to walk away and have Rufus follow her.
Animator Ollie Johnston did an extensive observation of the albatross in order to correctly animate Orville. He had an easy time making a realistic albatross landing "funny", but for the take-off, he decided to rely on gasping as well as feet thumping noises in order to create the comic effect he wanted.
Actor Phil Harris, who had played Baloo the bear in Walt Disney's The Jungle Book (1967), Thomas O'Malley in The AristoCats (1970) and Little John in Robin Hood (1973), was almost brought again for yet another comic role in this film. However, the dramatic nature of the film called for comic relief characters and humor gags to be toned down, so only the characters of Orville and Luke were left.
The film was the last of the Disney classics to be announced for a DVD release, receiving no more publicity than the standard press release. Even so, it became a popular seller and sold much better than expected. Walt Disney Home Entertainment had understocked the DVD, and copies were high on demand.
The talking animals in this film can communicate not only with other animal species but also with human children who bother to begin conversation with them. The 1977 "Disney's Wonderful World of Reading" picture book based on the film revealed that the reason Rufus had not told of Penny's fate to another child at Morningside Orphanage was because no child or adult had bothered to ask him. It is unknown whether Rufus could have spoken to a human child without being talked to first, or if he could talk to grown-ups at all.
The popularity of the film almost led to a spin-off TV-series in 1989; however, when the animation department green-lit its sequel, The Rescuers Down Under (1990), the project was scrapped. The series was still made, but Bernard and Miss Bianca were replaced with Chip and Dale, and the series was called Chip 'n' Dale Rescue Rangers (1989).
According to their publisher, The Rescuers (1977) helped put all of British author Margery Sharp's "The Rescuers" novels on the bestseller lists; not just "The Rescuers" and "Miss Bianca", on which the film is based, but all nine of them.
Fans of Walt Disney animation, and animation in general, have often mistakenly referred to the sometimes "sketchy" style in this film, as well as in others such as The Sword in the Stone (1963) and The AristoCats (1970) as "lazy" and budget-cut. In fact, the veteran animators working on these films, particularly Milt Kahl, strongly objected to their drawings being altered in any way and demanded that they should appear on the film's animation cels exactly as they had been drawn.
Even though most of Walt Disney Productions' films during the early '60s and '70s were shown theatrically in the aspect ratio of 1.75:1 they were actually animated in 1.37:1. This is the first non-Scope release to be animated in another ratio (in this case, 1.66:1).
The film was considered by Walt Disney's marketing department to represent the decade of the '70s in their prestigious Diamond Edition line introduced in 2009. However, in the winter of 2012, it was announced that it would instead be released as a "2-Movie Collection" commemorating its 35th Anniversary, and packaged along with its 1990 sequel.
Madame Medusa's fiery red dress and hair and Penny's light blue overalls use their color to contrast the theme of good and innocence against evil. This use of color for personification was later used in other Walt Disney Company films such as Beauty and the Beast (1991) and The Hunchback of Notre Dame (1996).
Louis Prima was set to play the deleted character Louis the Bear in an earlier script. He had recorded four songs and much of his character's dialogue for the film, but he underwent brain surgery in 1975, and never regained consciousness. The material, and his character, was not used in the film.
Sammy Fain's original version of "Someone's Waiting for You" commenced with a stanza not heard in the final film: "Every child has many wishes / that they wish when they're alone. / Faith can work just like magic, / nothing changes when you're grown." It is unknown whether the song's singer, Shelby Flint, ever performed and recorded this missing stanza.
Performer Nancy Adams, whom had previously appeared in Robin Hood (1973) singing "Love", recorded a demo for Sammy Fain's "Someone's Waiting for You" which was not used in the final film. The recording is believed to have been lost.
The song "Someone's Waiting for You" was originally entitled "The Need to Be Loved" with lyrics by Paul Francis Webster as opposed to Sammy Fain. Two demo recordings of the song exist, one featuring Webster and another with Jennifer Paz, and are to be released as part of a collection of unused songs entitled "The Lost Chords."
Orville the albatross hums the US Air Force theme "Into the Wild Blue Yonder" when he first meets Bernard and Bianca at the airport. He even mentions going to the "wild blue yonder" before they board the sardine can.
The film was originally released in 3 Channel Stereo much like Fantasia in 1940, but however due to major problems with sound equipment, the film was released in some parts of the U.S., Canada, and Mexico in monophonic sound. However, when Dolby Stereo dominated almost all sound film production in the 80's, the film was released in stereo once again in 1983. The film was still screened in mono sound in some theaters in the Midwest who were unwilling to equip with Dolby Stereo, but in all home video releases it is in true stereo sound.