E
edward
Guest
Hi Alan,
You beat me to it, I was digging out my copy of the Concise Oxford Dictionary of Zoology.
There is some argument as to whether some of the aquatic turtles actually are hibernating as they move up and down the thermocline as needed to maintain optimal body temperatures and species such as Glyptemys insculpta and Chelydra serpentina are rountinely seen actively swimming under the ice. In some species, the exposure to the cold appears to not be needed to reset the clock as a change in photoperiod and a temperature drop seem to work as well but this is very species dependent(a temperature drop and change in photoperiod are all that is needed for Clemmy guttata and Pseudobranchus a. axantha for examples in my experience (also a bunch of colubrids work this way)).
The reason I used (and prefer) the word torpor even though it is probably better applied to endotherms is this is how a lot of reptiles and amphibians do function. They are inactive but as long as they are not totally frozen solid can and do routinely move as needed and can become much more active with a few degree increase in during the day. As far as I can tell in the literature, herps that do not freeze as part of thier overwintering strategy do not sleep but are still aware but inactive (many denning snakes behave this way).
Ed
You beat me to it, I was digging out my copy of the Concise Oxford Dictionary of Zoology.
There is some argument as to whether some of the aquatic turtles actually are hibernating as they move up and down the thermocline as needed to maintain optimal body temperatures and species such as Glyptemys insculpta and Chelydra serpentina are rountinely seen actively swimming under the ice. In some species, the exposure to the cold appears to not be needed to reset the clock as a change in photoperiod and a temperature drop seem to work as well but this is very species dependent(a temperature drop and change in photoperiod are all that is needed for Clemmy guttata and Pseudobranchus a. axantha for examples in my experience (also a bunch of colubrids work this way)).
The reason I used (and prefer) the word torpor even though it is probably better applied to endotherms is this is how a lot of reptiles and amphibians do function. They are inactive but as long as they are not totally frozen solid can and do routinely move as needed and can become much more active with a few degree increase in during the day. As far as I can tell in the literature, herps that do not freeze as part of thier overwintering strategy do not sleep but are still aware but inactive (many denning snakes behave this way).
Ed