tree frog hibernation

Question
I live in Idaho and have 4 tree frogs that we caught this summer.  I am trying to hibernate them in the refrigerator since it is now winter. I put them in a container with a dirt mixture so they could bury themselves since that is what the information I could find said to do.  They have been in the refrigerator for about 2 1/2 weeks and still haven't buried themselves in the dirt. The refrigerator is between 36-38 degrees.  Do I need to cover them with leaves or something so they don't dry out?  I have a small lid in there with them that I keep water in to try to keep the humidity up. They will move if I touch them so I know they are alright so far but it will be at least 4 months before the weather is good enough to put them out. Thank you for your help and advice!

Answer
Hi Dianna,

I'm assuming that you have Pacific tree frogs. Your temperatures sound fine and should trigger them to bury on their own. You might try adjusting the consistency of the hibernation medium by mixing in some spagnum moss to give it a looser, less dense texture. More like loose vegetation/leaf litter rather then soil. You can dampen the moss slightly as well to mimic the higher humidity found below the surface level.

Ideally they should burrow on their own. If they don't and you are intent on hibernating them then I would suggest placing a layer of medium over them.

I'm sorry I couldn't be more helpful. I don't actually have personal experience with fridge hibernation because I work with tropical species. Their cooling requirements are far more easily met. :) Turning off the heat source and a cool room is sufficient for them.