Picture these happenings:
A family arrives in an Eastern resort city and checks in at a well-known hotel. Grabbing their attention in the Victorian-style lobby is a 30-foot-tall brass birdcage with five life-size, brightly colored, fully animated macaw birds perched inside, singing witty lyrics. Every hour, the computer-controlled ''birds'' perform six different two-minute shows.
Or: A couple with young children goes to a fast-food restaurant for an inexpensive dinner. As they munch their pizza, they are amused by a stage show performed by nine life-size, walking, talking, singing, joking, animated animal characters.
These are just two of the many types of businesses using mechanical animals to attract customers these days.
Sophisticated three-dimensional lifelike or fantastic animated figures such as these were once found almost solely in top-ranking amusement parks. But fast-growing AVG Productions Inc., a leading animation design and special-effects company in Valencia, Calif., is trying to spread the trend to other businesses like restaurants, hotels, and even miniature golf courses.
The company builds scale models, entertainment and electromechanical animation displays, free-walking radio-controlled figures, and computerized, pneumatic, hydraulic, and electrical figures. It also manufactures most of its own pneumatic cylinders, interface boards, and electronic components.
Chief among AVG's current projects is the creation and mass production of an animated show for a new chain of family-restaurant-and-entertainment centers called Circus Playhouse & Food Emporium, a division of Jewelcor Inc.
AVG has also designed and built animated shows for the Castle Park chain of miniature golf courses. Still another project is an animated figure featured in a multimedia stage production to be taken around the country. And, in the planning stage, there's a major international attraction to be owned and operated by AVG Productions itself.
The company was begun by Alvaro Villa, a native of Colombia who came to the United States in the early 1960s as a student. Originally interested in aviation , he first worked for the space program. Later he went to Walt Disney Productions, where he created many new animation systems, several of which are patented.
In 1978 Mr. Villa started his own business in a workshop the size of a two-car garage with a crew of three. Today AVG -- named for Villa's own initials and that of his mother's maiden name -- is housed in a 12,000-square-foot building with approximately 30 employees. Gross revenues have reached a projected $2.5 million for fiscal 1981.
AVG's first contract was an expensive one -- building animated robots and outer-space aliens for ''The Battle of Galactica'' effects on the Universal Studios tour. The construction of miniature spaceship models for ''Galaxina,'' a Crown Pictures Inc. science fiction spoof, followed. Then AVG designed and built animation and special effects for ''Castle Dracula,'' a live stage attraction on the Universal Studios tour which opened in June of 1980.
After that the real fun began, for ''fun'' is what's behind this ''theatronics,'' as the AVG experts like to refer to their work. To the crew of artists and technicians, the whole point behind finding new ways to make the unreal appear to be real is to have as much fun as possible.
In this case, the fun came in producing some 130 unfrightening monsters of every color, shape, and disposition for the ''Monster Plantation'' attraction of Six Flags Over Georgia in Atlanta. This $3 million-plus ''dark ride,'' which opened to the public last June, is operated entirely by a central computer linked to the monsters by more than 7,000 feet of wire.
''We use standard equipment from a computer company,'' Villa says, ''and then have our own electronics department adapt this with the animated figures. Then the whole thing is packaged in a single console which will control the show.''