when reintroduced into their habitat, the species could face many problems due to years in captivity. relaxed selection and reproduction with no environmental pressure may have taken place for père david's deer, due to captive breeding, which can result in the loss of adaptive anti-predator behavior. it is possible that when fully released in the environment from captivity, after generations of offspring, the species could be unable to retain parasite-defense behaviors like grooming. if the population is reintroduced into the environment with no protection against tick infestation then they can face major problems if not adapted to that environment. since also no longer being adapted to other predators, such as tigers, it could cause confusion for the père david's deer. they could have possibly lost the memories of their ancestral predators. although, a study was done on the species that are in captivity using the sounds of tigers roaring and dogs barking and the deer did not respond to the barking of the dogs, but hearing the tiger roar caused the deer to spend more time being cautious after hearing the sound, thus showing that the deer still retained memories of their previous predator, the tiger.