That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information
While the importance of providing a shelter for pet herps is well-known, the question of where to place the shelter is often not given adequate consideration. In both zoo exhibits and home terrariums, I have noticed that animals sometimes refuse to enter perfectly suitable shelters. Studies carried out at the University of Sydney have recently shed some light on the factors that influence shelter choice in lizards.
Safety vs. Warmth
Writing in the journal Behavioral Ecology (21:72-77), researchers report that Velvet Geckos (Oedura leseurii) avoided shelters that carried the scent of their predators (in this case, Broad-Headed and Small-Eyed Snakes). The geckos refused to enter the shelters despite the fact that they represented the only warm areas within the enclosures, choosing instead to hide in cold shelters. When the cold shelters were also scented, the geckos remained in the open. The experiment was repeated in the geckos’ natural habitat, with the same results.
Practical Applications for Pet Owners
While this behavior might seem to “make sense” to us, I think it is important to bear in mind that hiding from predators and thermo-regulating are key aspects of reptile and amphibian survival. Remaining in the open is very stressful for most species, and may lead to illness and death. Similarly, the failure to maintain the correct body temperature is a direct threat to their survival.
Other Considerations
While we do not (hopefully!) house our pets with their predators, other factors may be at work. For example, I have found that many animals will remain in a shelter even if the temperature within is too hot or too cold – safety trumping thermo-regulation in these cases.
Also, dominant tank-mates may prevent others from using shelters or basking sites, or cause them to remain within shelters for extended periods (thereby affecting feeding and basking behavior). This can occur even in the absence of actual aggression – the mere presence of a dominant animal is often enough to influence the behavior of other animals.
Where highly territorial, visually-oriented animals are concerned, a dominant individual can cause stress just by being within the view of another animal, even if housed in a different terrarium. I have observed this to occur among both chameleons and monitor lizards.
Further Reading
Turtles need shelters other than their shells! Please see my article on Turtle Shelters.
Please see this Herpetologica article abstract for information on other factors that influence shelter choice.
Thanks, until next time,
Frank Indiviglio
Lesueur’s Velvet Geko from Sydney image referenced from wikipedia and originally posted by Hexasoft
Very interesting that the Geckos would not enter hides with their predators scent. A friend and I have found Kingsnakes and Rattlesnakes in the wild sharing the same hides during the winter months. I have often found it useful to provide two hides in all my enclosures whether there are multiple occupants or not but especially with multiple occupants. Thus allowing for the reptile to choose whether it wants to be cool or warm.
Hello John, Frank Indiviglio here.
Thanks for your comment and observation. We see something similar here in the Northeast; i.e. a co-worker of mine noted an American Bullfrog basking near a northern Watersnake in an artificially warmed (but still cool) abandoned pump house one winter, and I’ve seen the same in early spring outdoors.
The shelter concept needs more attention I think, may explain some otherwise perplexing captive situations.
Good luck and please keep me posted.
Best regards, Frank Indiviglio.
Fascinating interpretation of some neat research. Are you familiar with the “Retes stack” idea?
On my recent trip to SD zoo one thing I found fascinating(practical probably only in SD and similar environs) was that each enclosure in the reptile house appeared to be equipped with a skylight…made for difficult photography but you could tell that at least some of the reptiles were very appreciative.
Hello Joseph, Frank Indiviglio here.
Thanks for the note; you’re looking at the right things; skylights make a huge difference in appearance and behavior. Even here in NY, skylights in the world of birds, reptile holding areas and elsewhere prove invaluable. I had one built into the centerpiece exhibit (Sonoran Desert) for the Staten Island Zoo’s reptile house as well, public and animals seem to like it. UVB-permeable glass is available now, but quite expensive.
Good luck and please keep me posted.
Best regards, Frank Indiviglio.
Hey Frank, I recently had a conversation with Dr. Robert Sprackland about this and other subjects. There seems to be a lot of interesting research going on with the UVB lighting and exposure do you know of any publicly accessible reports?
Hello John, Frank Indiviglio here.
Thanks for your interest in our blog.
The research is spread widely but I monitor the Journal of Herpetology and others and post updates – you might enjoy this article on Chameleon Basking Behavior.
UVB UK seems like a good central location for checking recent findings.
W. Gehrmann is an expert on the subject, especially as regards the technical aspects of bulbs etc. He was a great help to me when I was setting up the new Reptile House at the Staten Island Zoo. Anything he publishes is well worth reading.
Good luck and please keep me posted.
Best regards, Frank Indiviglio.