Comparative migration strategies of wild and captive-bred Asian Houbara Chlamydotis macqueenii

For migratory species, the success of population reintroduction or reinforcement through captive-bred released individuals depends on survivors undertaking appropriate migrations. We assess whether captive-bred Asian Houbara Chlamydotis macqueenii from a breeding programme established with locally sourced individuals and released into suitable habitat during spring or summer undertake similar migrations to those of wild birds. Using satellite telemetry, we compare the migrations of 29 captive-bred juveniles, 10 wild juveniles and 39 wild adults (including three birds first tracked as juveniles), examining migratory propensity (proportion migrating), timing, direction, stopover duration and frequency, efficiency (route deviation), and wintering and breeding season locations. Captive-bred birds initiated autumn migration an average of 20.6 (±4.6 se) days later and wintered 470.8 km (±76.4) closer to the breeding grounds, mainly in Turkmenistan, northern Iran and Afghanistan, than wild birds, which migrated 1217.8 km (±76.4), predominantly wintering in southern Iran and Pakistan (juveniles and adults were similar). Wintering locations of four surviving captive-bred birds were similar in subsequent years (median distance to first wintering site = 70.8 km, range 6.56–221.6 km), suggesting that individual captive-bred birds (but not necessarily their progeny) remain faithful to their first wintering latitude. The migratory performance of captive-bred birds was otherwise similar to that of wild juveniles. Although the long-term fitness consequences for captive-bred birds establishing wintering sites at the northern edge of those occupied by wild birds remain to be quantified, it is clear that the pattern of wild migrations established by long-term selection is not replicated. If the shorter migration distance of young captive-bred birds has a physiological rather than a genetic basis, then their progeny may still exhibit wild-type migration. However, as there is a considerable genetic component to migration, captive breeding management must respect migratory population structure as well as natal and release-site fidelity.