|Posted by loriana12 on May 4, 2019 at 3:30 AM|
May 2019 Pilot Study Update
Lori A. Torrini, CPDT-KA, A.A.S.
This seems to be a controversial subject among snake keepers, breeders, and hobbyists. Since I began to research this topic over a year ago, I have read and heard opinions from “never do it” to “I have done it for years with no problems” and everything in between. I have searched for scientific studies into the subject and been disappointed to find none, other than some on communal behavior of snakes in the wild and cohabitation of breeding pairs or groups in captivity.
Personally, I find it much easier as a keeper of multiple snakes to house them individually. This way I am dealing with just one animal at a time when I have the enclosure open, I know which one shed, drank water, eliminated, etc. I can feed it in the enclosure or out without having to worry about another snake nearby, and I can conduct training without another snake interfering. With that said, there are some keepers who, for their own reasons, would like to keep more than one snake together, maybe to observe behavior to maximize resources, etc. Either way, the most important thing should be what is best for the welfare of the animal. If, in fact, snakes prefer to be in the company of conspecifics or, to at least have that option available, then we should be providing them the opportunity.
The American Pet Products Association reported for 2017-2018 that 9.4 million reptiles are kept as pets in United States households. The American Veterinary Medical Association reported in 2012 that 555 snakes were being kept as pets per every 1000 households in the United States. These numbers do not include those snakes kept in zoos or those maintained in herpetoculture for breeding and sale into the pet trade. Despite large numbers of snakes under human care there is a lack of research regarding their social behavior and preferences. The question this study will endeavor to answer is whether snakes kept under human care prefer to be housed individually or in pairs/groups. Ask anyone in herpetoculture if pet snakes should be kept individually or together and responses will be from one extreme to the other.
While one snake owner, breeder, or pet shop clerk may make statements such as: “snakes are solitary animals”, “snakes prefer to be kept alone”, “snakes should never be housed together”, and “snakes could cannibalize each other”; others will make statements such as: “I have always kept pairs of snakes together”, “my snakes have been housed together all their lives”, “I keep breeding pairs together all year long”, and “snakes huddle together for warmth”. These previous statements are anecdotal. They are not based on empirical scientific research. The quest to uncover previous behavioral studies to support any of these claims has come up empty. This pilot study will be an important first step in providing answers based on actual scientific observations of snake social behavior in a captive setting.
The facts as I have been able to find, or not find, simply do not tell us if snakes maintained under human care (in captivity) prefer the opportunity for the company of conspecifics or not. Clearly some species predate upon other snakes and even those of their own kind, and others spend time with multiple members of their kind in communal hibernacula and other settings on occasion in the wild. There have simply not been any controlled scientific studies on cohabitation of snakes under human care with any published findings.
The following studies were the only ones found relevant to aspects of snake social behavior that did not specifically involve breeding, prey capture, and basking behavior. While they do address aspects of snake social behavior relevant to communal living, except for one these were conducted in the wild and not in captive environments. The one conducted in 1975 and published in 1977 observed a group of 4 males with 1 female Indian Python and studied the social hierarchy regarding dominance in breeding behavior.
• Dinets, Vladimir. 2017 “Coordinated Hunting by Cuban Boas”. Animal Behavior and Cognition 4 (1): 24-29. Open Access.
• Alexander, G. J. 2018. “Reproductive Biology and Maternal Care of Neonates in Southern African Python (Python natalensis)”. Journal of Zoology; Zoological Society of London. Press Release.
• Amarello, Melissa. 2012. “Social Snakes? Non-random Association Patterns detected in a Population of Arizona Black Rattlesnakes (Crotalus Cerberus)”. Arizona State University, USA. Master’s Thesis.
• Amarello, M. 2012. “Social Snakes? The Role of Kin Selection in Rattlesnake Aggregations”. Sonoran Herpetologist 25: 129-130.
• Barker, D.G. 1979. “Social Behavior in a Captive Group of Indian Pythons with formation of a Linear Social Hierarchy”. Copeia, 466-471.
Through Spirit Keeper Equine Sanctuary 501c3 and Behavior Education LLC, with assistance from Pikes Peak Community College Zookeeping interns, I am conducting a pilot study. This pilot study is designed to answer the question of whether snakes given the opportunity and choice will remain solitary or near other snakes when provided two identical connected enclosures. When two snake enclosures with identical environments that are carbon copies of each other in every way (i.e. duplicate layouts, furniture, perching, hides, water, heating, lighting, vegetation, etc.) are connected so that each snake may access both, will the snakes remain apart from each other or near each other most of the time? This must be a long duration study. The animals must be observed throughout the year and throughout their various life-stages as behavior may change based on age and seasonal fluctuations.
For over a year now I have been observing four cohabbed pairs of snakes from the genus Morelia. I have the animals in carefully controlled and monitored set-ups and keep detailed journal notes on them. I plan to continue the current study and to set-up additional pairs for observation. I journal their behavior and record statistics as to how much time they spend together versus separate when given choice and control. No agonistic behaviors, conflicts, or failure to thrive have been observed in these four pairs to date. The current pairs are as follows: M/F 2017 Morelia spilota variegata, M/F adult Morelia spilota unknown subspecies, F/F 2017 Morelia spilota harrisoni, and F/F 2018 Morelia spilota harrisoni. Animals pending pairing are sub-adult Morelia spilota metcalfei and Morelia bredli. Statistics are being pulled from the logs and a time budget is being produced. In general, the F/F pairs spend less time together the older they get. The M/F pairs spend most of their time together versus separate; this is observed in the adult pair and in the sub-adult pair. Interestingly all four pairs spend time basking together for several hours after they have been separated for feeding and placed back inside their enclosures. 100% of the time they move around the enclosure(s) immediately following their return from eating until they locate each other; then, they coil together in the same basking area for several hours.
The four pair of Morelia spilota currently observed indicate a preference to be with conspecifics some of the time. No agonistic, bullying, or conflict behavior has been observed. The animals are consistent feeders that express natural behaviors free from any indicators of fear or distress. It is not known if their individual personalities or behaviors would change if permanently separated.
Based on my findings so far, I would offer these considerations for anyone thinking of cohabbing snakes:
• Choose a species that is not known to engage in ophiophagy.
• Choose male/female or female/female cohabitants as some males engage in male to male combat during breeding season.
• Set up two enclosures with identical furnishings and resources in each and then connect the enclosures; or, set up one double-sized enclosure with resources duplicated (2 of everything). SEE VIDEO EXAMPLE BELOW.
• Two connected enclosures or one large enclosure with duplicated resources will allow everyone the choice and control over utilizing resources alone or with the other animal and will give one animal the opportunity to move away from the other animal if it chooses.
• Monitor the animals closely for any signs of stress, agonistic behavior, health issues, or general failure to thrive.
• Consider surveillance cameras to monitor the animals when you are not there to watch them in person.
• Divide the enclosure or separate the animals for feeding to avoid feeding accidents or conflicts over food.
• If you are training the animals, separate them so that they may be worked with individually during training sessions.