They were a secret airborne force who worked undercover during World War II. Those who were discovered were shot — or eaten by falcons.

The feats of Britain's wartime pigeons, who flew dangerous missions to bring messages from behind enemy lines, are being recalled this month with an auction of naturalistic portraits of some of the birds' ancestors.

The paintings depict birds owned by a Belgian collector who sold British breeder Jack Lovell eight pairs of breeding pigeons in 1935. Four years later, Lovell was approached by British intelligence services planning covert operations against Germany — and the pigeons' offspring were soon mobilized.

Pigeons' homing instinct makes them excellent messengers, and more than 200,000 served with British forces during the war.

Thousands of members of an elite avian unit, based in secret pigeon lofts in the coastal city of Dover, were placed in containers fitted with parachutes and dropped by British bombers behind enemy lines, where they were picked up by Resistance fighters or sympathetic locals and used to send messages back to England.

Others worked as double agents, fitted with tags identical to those worn by Nazi-owned pigeons in the hope they would be given coded messages which they could bring to British codebreaking headquarters at Bletchley Park, near London.

In all, 32 pigeons were awarded the Dickin medal, Britain's highest award for animal valor. They include an American bird named GI Joe, credited with flying 20 miles (30 kilometers) in 20 minutes with a message that stopped U.S. planes bombing an Italian town occupied by British troops.

The Bonhams auction on Jan. 15 also includes a silver candlestick inscribed to Jet, a German shepherd awarded the Dickin medal for finding survivors in the rubble of bombed London buildings.

But not all items conjure up memories of the war.

Most accessories are aimed at "a gentleman's library," the auction house says, including walking canes, humidors, furniture, bronzes, busts and lamps.

And what gentleman's library would be complete without a tiger skin rug with mounted head; a Boy Scout hat once owned by the movement's founder, Robert Baden-Powell; a pair of glass cucumber straighteners; or a lock of hair belonging to Catherine Parr, sixth wife of Henry VIII?

Bonhams director Robert Bleasdale said the items were intended to reflect a sense of "comfort, nostalgia, the unusual, fun."

"It's more of a gentleman's indulgence, really," he said.