Comparing fostering success between wild-caught and game farm bred captive red-legged partridges (Alectoris rufa, L.)

Abstract As fostered game birds are better prepared for releasing in comparison to those intensively reared, fostering of wild and game farm red-legged partridges ( Alectoris rufa ) was studied on a semi-natural rearing farm using farm-hatched chicks. Parent pairs, barren pairs and single individuals from wild and game farm strains were used in a total of 208 attempts. Fostering was observed in both strains, but more successful attempts were in wild parent pairs (27 of 29 pairs, 93%) than in the game farm strain (12). In the game farm strain all fostering was done by barren pairs and single individuals; as none of the game farm pairs raised their own chicks it was not possible to test game farm parent pairs. Wild parent pairs also showed a high percentage of fostering at a second attempt one week after the first (25 of 27 pairs, 93%), suggesting that fostering is strongly related to parental care behaviour. A low proportion of barren pairs and singles adopted unrelated chicks (9%), with most of these (12 of 13 attempts) being farm-bred. When fostering was observed, adults displayed behavioural patterns related to parental care (brooding and calling) and spent 35% of time in proximity to chicks, compared to 19% and absence of parental care when fostering was unsuccessful. Successful fostering increased brood size four weeks after hatching by 4.4 ± 2.3 fostered chicks. This study suggests that fostering for releasing purposes is a feasible technique in semi-natural rearing systems. Wild strains of partridges and parent pairs should be chosen as foster parents.