In 1903, Julius Neubronner, an apothecary in the German town of Kronberg near Frankfurt, resumed a practice begun by his father half a century earlier and received prescriptions from a sanatorium in nearby Falkenstein via pigeon post.
He delivered urgent medications up to 75 grams (2.6 oz) by the same method, and positioned some of his pigeons with his wholesaler in Frankfurt to profit from faster deliveries himself.
When one of his pigeons lost its orientation in fog and mysteriously arrived, well-fed, four weeks late, Neubronner was inspired with the playful idea of equipping his pigeons with automatic cameras to trace their paths.
This thought led him to merge his two hobbies into a hybrid activity, combining carrier pigeons with amateur photography. Neubronner began the development of a light miniature camera that could be fitted to a pigeon’s breast by means of a harness and an aluminium cuirass. Using wooden camera models weighing 30 to 75 grams (1.1 to 2.6 oz), the pigeons were carefully trained for their load.
To take an aerial photograph, Neubronner carried a pigeon to a location up to about 100 kilometres (60 mi) from its home, where it was equipped with a camera and released. The bird, keen to be relieved of its burden, would typically fly home on a direct route, at a height of 50 to 100 metres (160 to 330 ft). A pneumatic system in the camera controlled the time delay before a photograph was taken. To accommodate the burdened pigeon, the dovecote (the structure that houses pigeons or doves) had a spacious, elastic landing board and a large entry hole.
Initially, the military potential of pigeon photography for aerial reconnaissance appeared attractive. Battlefield tests in the First World War provided encouraging results, but the ancillary technology of mobile dovecotes for messenger pigeons had the greatest impact. Owing to the rapid perfection of aviation during the war, military interest in pigeon photography faded and Neubronner abandoned his experiments.
The idea was briefly resurrected in the 1930s by a Swiss clockmaker, and reportedly also by the German and French militaries. Although war pigeons were deployed extensively during the Second World War, it is unclear to what extent, if any, birds were involved in aerial reconnaissance. The United States Central Intelligence Agency (CIA) later developed a battery-powered camera designed for espionage pigeon photography; details of its use remain classified