The Discovery Channel's one-hour premiere of "The Wild Horses of Australia" (Monday at 9) reveals why these beautiful and independent animals, once vital to survival in the Outback, are now considered outlaws.

The special features some wonderful photography of horses charging across the hillsides, along with excerpts from the lyrical ballad "Man From Snowy River." And the narrative offers such apt lines as: "It was grand to see that mountain horseman ride." It sure is.

Horses are among Australia's most beloved animals, but the over-population of these free-roaming brumbies, as Aussies call them, is damaging the natural environment of the fragile continent and driving other native wildlife to extinction.

This is no small problem. Horses were introduced to Australia to help settle the land in 1788. Championed as faithful cavalry steeds, 120,000 were shipped to British forces during World War I. But since they were displaced by technology and set free after that war, the number of wild horses in Australia has grown unchecked -- to as many as 300,000 to 600,000 brumbies, by some estimates -- and they are increasing by as many as 150,000 a year. In the United States, the number of wild horses was down to 17,000 in 1971 when the Wild Free-Roaming Horse and Burro Act was passed protecting the wild breeds. There are an estimated 44,000 this year.

Current means of managing the brumby population include setting up trap yards around water holes, trucking them to slaughterhouses and exporting the meat to Japan, Belgium, Luxembourg and the Netherlands; and shooting the brumbies from helicopters. Aussies note that helicopter culling is the preferred and most humane method, using competent professionals to kill the horses instantly and cleanly.

The overpopulation of wild horses is of major concern to conservationists and ranchers. Lacking natural predators, horses compete with native fauna, as well as domestic livestock, for limited sources of food, shelter and water. They consume vast quantities of water and 20 to 30 percent more food than cattle.

Continuous pounding of the soil by brumbies also hampers the ground's chances of regenerating and satisfying other wildlife. During times of drought, wild horses also dry up water holes and graze off available vegetation, leaving other native animals to starve.

Producer/director Gary Steer has been a pioneer in Australian wildlife documentary. His love for animals -- horses, in particular -- goes back to his youth and days of "jackarooing" (herding sheep on a ranch). He has 28 documentaries and short films to his credit and is the founder of Sky Visuals, which co-produced this program with TDC. Steer's works seen on U.S. television include "Wild Dog Dingo," "Australia's Improbable Animals," "Camels Outback, Eh?" and upcoming on National Geographic, "Kula: Ring of Power."

This is his first production for The Discovery Channel, which plans what it calls a "new special premiere" each quarter hereafter. The network believes its additional original programming has attracted additional viewers: October prime-time ratings are up 43 percent over October 1989.

Repeat showings of this special are scheduled for Friday at midnight, Saturday at 3 p.m., Dec. 16 at 2 p.m., Dec. 18 at 10 p.m. and Dec. 22 at 1 a.m.

Sunday on The Disney Channel at 9:30 p.m. another vintage Frank Sinatra special: his 1971 debut on network television taped at London's Royal Festival Hall. He is introduced by the late Princess Grace of Monaco and his songs include "The Lady Is a Tramp," "My Way" and "I've Got You Under My Skin."

Monday on TNT at 9 p.m. Glenn Close hosts "The Divine Garbo," a one-hour retrospective chronicling the life and career of the glamorous Greta Garbo. Following the special, TNT will air one of Garbo's biggest hits, the 1936 tragic love story "Camille." TNT will show six other Garbo movies during the week. "The Divine Garbo" encores Monday at 11:30 p.m. and Saturday at 8 p.m.

Monday on Showtime The premiere of an original holiday children's special, "The Gingham Dog and The Calico Cat," which utilizes a unique form of dissolve animation. Singer Amy Grant provides the narration with original music by Chet Atkins and illustrations by Laszlo Kubinyi. Repeats: Dec. 12, 16, 21 and 27.

Thursday on TNT at 8 p.m. Dr. Seuss' holiday favorite, "How The Grinch Stole Christmas," returns. This show holds the distinction of being the highest-rated entertainment program to air on TNT. Encores: Dec. 9 and 12.

Saturday on Lifetime at 10 p.m. The premiere of "Kenny Rogers' Christmas in America," in which Rogers reminisces about Christmas during four different stages of his career. Repeats: Dec. 15 at 2 p.m. and Christmas Day at 1 p.m.

Saturday on The Nashville Network at 5:30 p.m. "Home for the Holidays," a 30-minute special, features songs from a new RCA album (same name) with Clint Black, K.T. Oslin, Baillie & The Boys, Restless Heart, Paul Overstreet, Foster & Lloyd, and Prairie Oyster. Some songs were written by those artists for the album and have never been performed on television. Repeats: Dec. 18 and Dec. 24, both at 8:30 p.m.