Long lasting breeding performance differences between wild-born and released females in a reinforced North African Houbara bustard (Chlamydotis undulata undulata) population: a matter of release strategy

摘要

The success of translocation programmes is reflected by the ability of translocated individuals to survive and reproduce in their new environment. However, it has previously been reported that translocated individuals have lower demographic performance than their wild-born conspecifics, due to management and individual factors (such as release conditions or age). Here, we study six breeding parameters in free-ranging females of the North African Houbara bustard (Chlamydotis undulata undulata) and compare these parameters between captive-bred released (n=204) and wild-born (n=101) birds, considering the age of individuals and the period of release (autumn versus spring). Our results indicate that (1) captive-bred released females successfully breed in the wild; (2) for three out of the six breeding parameters studied, released females show lower performances than wild-born females; but, (3) Although we observed consistently reduced breeding performances in 1year old females relative to older females, we did not uncover any interaction between age and the origin of females, suggesting that the impairment of breeding parameters in released females is long lasting; and, (4) interestingly, this impairment of breeding parameters depends on the period of release, with lower breeding performances for spring releases compared to autumn releases. Overall, our study highlights the capacity of captive-bred females to reproduce in the wild, contributing to the dynamics of the population beyond their individual history. Our results also uncover complex variations of breeding parameters in translocated birds, but suggest that these differences can be minimized through an appropriate translocation strategy.