Jake,
The conventional thought for eons has been that during the winter in the northern hemisphere, reptiles hibernate. Well, that is partly true, particularly east of the Sierra Nevada and Cascade Mts. to the Atlantic. S. Florida, Texas, etc there are exceptions. However, west of those mountains to the Pacific, here on the west coast we have a rather unique situation in which during the winter months, there can be relatively frequent periods of decent weather in which the sun shines for a number of days accompanied by mild temperatures; mild meaning from the mid 50 degrees F. and above.
Under those circumstances, some species of reptiles will come to the surface or beneath surface objects to thermoregulate. Beside the species William (Fieldnotes) mentioned, the Southern and Northern Alligator lizards commonly can be found during late fall and winter months of November, December, January and 'February. Even the W. Fence Lizard can be observed at such times, usually when the sun is out and air temperatures at or above 60 degrees, especially on south facing slopes.
I live in western Oregon and ever since 1971, I have never failed to find the Rubber Boa during the month of Feb. About every 3-4 years, I will find the species during the month of Jan. and on occasion have found them during December as well. It is not that uncommon to find the species during the firsts couple of weeks of Nov. The same applies to the Sharp-tailed Snake which is even more unusual in that it can continue to feed and digest prey with temperatures in the high 40's into the 50's and above during the winter months. In a study on that species published by Cook in 1960, I believe the peak period of when the Sharptail was observed in Calif. was Feb. and March.
Past input on this and other forums from Calif. residence indicate the same scenario only with greater frequency as your temperatures, especially near the coast, are even more mild than they are here in the Willamette Valley of W. Oregon. So a researcher mentioned finding a boa last Jan. 25 in he Santa Cruz Mts. which I duly recorded and place in my folder dealing with such matters. I believe Brian H. (Fundad) a couple of years ago mentioned it was not all that in the LA to San Diego region, it was not uncommon to find S. Pac. Rattlers, Gopher Snakes and Common Kingsnakes (perhaps other species) beneath cover objects during suitable conditions during the winter.
When my children were young, they lived with their mother in Lucerne, Calif. along the NW shore of Clear Lake in Lake County. I went to visit them for two years during Christmas time between Dec. 23 - 30th. In those two years, we found a Common Kingsnake, Ringneck Snake, two Sharp-tailed Snakes, W. Fence Lizards, S. All. Lizards, and W. Skinks. One year the frost remained unmelted in the protected shaded areas of the south facing hills but with totally sunny skies, those south facing slopes obviously warmed subsurface temperatures sufficiently to bring out those species.
It's a nice challenge to find herps, including reptiles, during the winter months.
Richard F. Hoyer
