Other updates:

Frog 5 (Lil' Porker) has croaked a few times this past week. Here is a record of vocalization activity:

12/23/11: 2 croaks in the morning at 6:45 am. Temperature was 65F, humidity unknown. Snow was in the forecast.
12/25/11: 2 croaks in the mornig at 6:30 am. Temp/hum unknown :P. There was heavy snow that day.
12/27/11: 5 chirps in the afternoon (between 12:30 am and 1:00 pm). Unsure if it was Lil' Porker or his tank mate Lil' Piggy (frog 6). Temp was 70F and humidity was 50%. Now snow in forecast, but cold temperatures.

On Monday, 12/26/11, upon spraying the terrarium, Lil' Porker tried to mate with Lil' Piggy. This time, Piggy gave out release calls. Porker let go.