“French pigeon trainer, France, during World War I. This photograph shows a French Army officer holding a carrier pigeon ready to fly. Below the rank chevrons on his sleeve he is wearing a badge of a flying pigeon, showing he was a pigeon trainer. He has the weather-beaten skin of a countryman.
“On September 11, 1914, the French gave 15 pigeons to the British Intelligence Service. By 1918 there were some 20,000 birds and 380 expert pigeon trainers in the British Army alone.”
UPDATE: From our Facebook friend the 18é Régiment d’Infanterie du Ligne: Great photo! However, the chevrons on his arm denote his combat experience and senority. Enlisted rank is located on the sleeve cuff (near the wrist) an looke like “hash” marks.