The National Wildlife Federation is going on television to tell the country that its national symbol, the American bald eagle, can be saved from extinction in the lower 48 states.

A new 30-minute documentary film, "We Can Save the Eagle," will be shown at 6:30 p.m. Sunday on WJLA-TV (Channel 7). It traces the history of the big predatory bird from colonial days, when it was found in every section of the country, to the present, when only 10 states can count more than 25 eagle nests.

The film was produced for the National Wildlife Federation by Anthony T. Lorch, a Rockville cinematographer. If some of the scenery looks familiar, that is because parts of the documentary were filmed at the 11-216-acre Blackwater National Wildlife Refuge near Cambridge, Md., which is maintained by the Interior Department's Fish and Wildlife Service. Last September, 38 bald eagles were counted there.Another segment of the documentary was filmed at the Patuxent Wildlife Research Center near Laurel, Md.

Drawings made by Montgomery County third graders at Park Street Elementary School in Rockville last May are also included in the documentary, along with the children's comments on why they like the bald eagle.

The film warns that the biggest threats to the bald eagle's recovery are destruction of its habitat, contamination of its food supply with pesticides and other poisons, and illegal shooting.

But there is a hopeful tone to the docementary as well. The biggest breakthrough in the campign to save the eagle, the film reports, has been the national ban on indiscriminate use of DDT and other long-lived pesticides which got into the bird's food chain a few years ago and impaired its ability to reproduce. Stronger federal laws, with stiffer penalties for the malicious killing and maiming of eagles, have also helped the eagle survive.

The film suggests several ways that people can help save the nation's symbol, such as leaving it alone and admiring it only from a distance; refraining from needlessly or recklessly destroying birds' roosting sites; opposing the use of long-lived pesticides; helping to acquire more eagle sanctuaries where eagles can hunt, fly freely and reproduce, and notifying the U.S. Fish and Wildlife Service if a dead or wounded eagle is spotted.

Environmental organizations can borrow the 16 mm color sound film free of charge or purchase prints of it from the National Wildlife Federation, 1412 16th St. NW, Washington, D.C. 20036.