Another interesting study was conducted by prominent a Herpetologist and Professor at CU, Dr. David Chizar. In 1995 I listened to Dr. Chizar's presentation of this study, while attending the International Herpetological Symposium.
This study looked at the feasibility of re-introducing captive bred "head started" Aruba Island Rattlesnakes (C. unicolor) to their NATIVE habitat, within an area set aside as a wildlife reserve.
They ran into some interesting data.
Comparing the "head started" captive bred snakes with wild snakes they found that the "head started" snakes essentially had "imprinting" problems. They would not be suited to survive in wild. These "head started" snakes lacked the skills needed to survive in their natural environment.
Wild Caught snakes reacted correctly to stimuli:
They sought refuge of heavy piles of rock or similar shelter when faced with a potential predator. (Such as a human or a dog.)
"Head Started" snakes would often associate humans with food....as they were used to receiving feedings from humans.
Inside the cage they would often witness the head-started c.b. snakes rubbing their faces on the glass in anticipation of feeding when these snakes saw humans.....or even when they saw Dr.Chizar's dog!
(Chizar often had his dog in the lab during the evening feeding sessions....and the snakes would associate human or canine presence with the offering of food items.)
I have also witnessed this face-on-the-glass-rubbing in several species of snakes including Elapids, Pythons, Boas, several Colubrid species and also Crotalus species. We often refer to this activity as "begging".
Wild snakes were able to effectively track their prey items after the bite.
C.B. head-started snakes performed very poorly at this task. They often failed altogether.
Dr. Chizar did a tongue flicks per minute study while the snakes were tracking their prey items.
The wild caught snakes scored off the chart...and rarely if ever got off course while tracking.
The head-started snakes scored poorly with low tongue flicks per minute and often got off track....sometimes they were unable to complete the task.
Head-Started snakes have a greater chance of being introduced to (and infected with) fatal reptilian diseases, while in captivity. This further diminishes their chances of surviving in the wild after re-introduction. It also opens more possibilities of spreading diseases to the wild populations.