Estimating sustainable harvest for the management of the eastern population of sandhill cranes (Antigone canadensis tabida)

Abstract

The Eastern Population of sandhill cranes has expanded rapidly from near extirpation in the early twentieth century. Rapid population recovery and range expansion have resulted in the increased take of the Eastern Population through crop depredation permits and hunting. To provide a better biological foundation for managing the Eastern Population, the management community desired a scientifically informed evaluation of take to maximize the protection and use of this species for 3 major purposes: wildlife viewing, control of crop depredation, and sport hunting. We used a prescribed take approach, which uses data from population, demographic, and management parameter estimates to determine the allowable take. Furthermore, we used 2 different methods of estimating growth rates to control for demographic uncertainties. We estimated a maximum growth rate of 0.092 to 0.123 for demographically informed and demographically invariant methods, respectively. Depending on management objectives, median take ranged from 3,123 birds at a low take management goal to 6,245 at the maximum sustained yield management goal. We found that this species can sustain current reported take and likely can sustain additional take if needed. Owing to inherent differences in productivity, driven by small clutch size and lower fledging success, sandhill cranes need to be more closely monitored for take compared to more fecund species.