The introduction of pen-reared Attwater's prairie-chickens (APC, Tympanuchus cupido attwateri) into the wild to supplement existing populations has met with marginal success. Flight characteristics, predator avoidance behavior, and rearing methods may contribute to post-release mortality of pen-reared birds. We compared flight characteristics and predator avoidance behaviors of pen-reared APC released onto the Attwater Prairie Chicken National Wildlife Refuge with those of a sister subspecies, wild greater prairie-chickens (GPC, T. c. pinnatus) in Minnesota and Kansas. There was no difference (P = 0.134) in flight speed of pen-reared APC and wild GPC. However, wild GPC flew further (P <0.001) in response to an approaching human than did pen-reared APC. Wild GPC flushed at a greater (P <0.001) distance from an approaching human than did pen-reared juvenile APC that had lived in the wild for less than 3 months. A trained dog was able to approach closer (P <0.001) to APC than to GPC before birds flushed, and APC did not fly as far as GPC after being flushed by a dog. The deficiencies in flight endurance and predator avoidance behavior of pen-reared APC compared to wild GPC could explain the high mortality of APC in the wild. Flight conditioning in circular flight pens using dogs to scare and harass captive birds at an early age could improve birds' predator avoidance behavior and increase flight endurance by allowing them to exercise their flight muscles. If the recovery of the APC is to succeed, the behavioral deficiencies of pen-reared birds should be addressed.