Induced triple clutching in captivity for three falcon species: Common Kestrel (Falco tinnunculus), Saker Falcon (Falco cherrug) and Peregrine Falcon (Falco peregrinus)

Triple clutching within a single breeding season is rarely documented in falcons, particularly under captive conditions. This study reports the occurrence of triple clutching in three falcon species — Common Kestrel ( Falco tinnunculus ), Saker Falcon ( Falco cherrug ) and Peregrine Falcon ( Falco peregrinus ) — reared in captivity in Bulgaria. Two breeding pairs per species were monitored during the 2011–2020 breeding seasons under controlled conditions with optimal husbandry and nutritional regimes. Clutch frequency, egg production, fertility rates, hatching success and chick survival were recorded for each pair. Results revealed that both monitored pairs of each species produced three successive clutches within a single season, with varying degrees of reproductive success. These findings suggest that under good captive conditions, triple clutching is a feasible reproductive strategy in falcons and may significantly enhance the productivity of conservation breeding programmes. Further research is needed to determine the physiological limits and welfare implications of induced high‑frequency breeding in raptors Triple clutching within a single breeding season is rarely documented in falcons, particularly under captive conditions. This study reports the occurrence of triple clutching in three falcon species — the Common Kestrel, Saker Falcon and Peregrine Falcon — maintained in captivity and monitored over the 2011–2020 breeding seasons. Two breeding pairs per species were observed under controlled husbandry and nutritional conditions and clutch frequency, egg production, fertilisation, hatching success, chick survival and breeding outcome were recorded for each pair. All monitored pairs produced three successive clutches within a single breeding season, although the mechanism differed amongst species. Triple clutching occurred naturally in Common Kestrels under full parental care, whereas in Saker and Peregrine Falcons, it was induced through egg removal and artificial incubation. Reproductive output remained high across successive clutches, with viable eggs and healthy chicks produced in all three species, despite some reduction in egg size in later clutches of Saker and Peregrine Falcons. These findings demonstrate considerable reproductive plasticity in falcons and show that, under favourable captive conditions, triple clutching can substantially increase breeding output. The results highlight the practical value of multi-clutch breeding for captive propagation and conservation programmes involving re-introduction or population reinforcement.