Pigeon flight in a wind tunnel

Summary

• 1. An 8 part 9 m long wind tunnel, built of wooden frames and chipboards supported by an iron tube base, specially suited for bird flight investigation, is described (Fig. 1, 2). The working section measures 1×1×1.4 m and consists of smoothly fitting interchangeable walls of glass, wood or metal. Maximum velocity is 24 m s⁻¹ (86 km h⁻¹). In the working section, velocity distribution is constant within 3% (Fig. 2c). Turbulence factors of 1.25 (15 m s⁻¹) to 1.4 (24 m s⁻¹) were measured.

• 2. Pigeons were kept in dovecots in the wind tunnel room to accustom them to tunnel noise. A 5 phase training program used to train pigeons to fly in the wind tunnel is described in detail.

• 3. Seven different pigeon races, including a newly bred hybrid, were tested. Homing pigeons were not fast enough for steering manoeuvers, hard to train and had varying flight styles. Nicolajew and Hannover pigeons interrupted their flight by pronounced gliding phases. Vienna and Serbian pigeons flew too nervously. English Tipplers flew permanently, but ‘swayed’ occasionally. Russian Griwunis flew calmly and steadily in flapping flight, sometimes interrupted by gliding periods. A hybrid from Tippler and Griwuni proved to be an ideal wind tunnel flier (Fig. 3), being easily trained and performing long, steady, powerful flights. Results are presented in a comparative manner with training diagrams (Fig. 4), flight time training relation (Fig. 5), flight ability data collection (Table 1) and mass loss data collection (Table 2). It is shown that Tipplers, Griwunis and especially the Grippler hybrids are suitable for wind tunnel experiments.