Reptile & Amphibian Forums

All the talk lately about winter activity has got me pretty interested in the activity patterns of snakes in some of the warmer areas of the country. I’ve had to adjust my thoughts considerably to get to this point, but I now believe some snakes tend to be active year ‘round, if allowed, and I’d like to know which snakes can be shown to be active in winter, and why would that be so? So I decided to search some literature and have come up with some ideas.

Last night I found a book that addresses the idea of activity patterns. It puts it in a light that I can understand well with my type of background and I’ll try to summarize it here. I think observations of snakes in winter are great, but they don’t tell us too much about the snakes. They do help identify which snakes are likely to be winter active, however, and I’m interested now in finding out which species are winter active, how often, and why. Special note is on the common kingsnake as this is a kingsnake forum.

The book I’m using as my source of information is, Snakes: Ecology and Evolutionary Biology, edited by Richard A. Siegel, Joseph T. Collins, and Susan S. Novak (1987). It is a collection of papers with an ecological and evolutionary theme. The paper I’m currently interested in is, “Activity Patterns”, by J. Whitfield Gibbons and Raymond D. Semlitch (Chapter 13, p. 397.) In their article they have researched eleven snakes, year ‘round, at the Savannah River Plant near Aiken, S. C. They have graphed the info on the activity patterns of these eleven snakes. Also they mention similar research on a few other snakes that I will list. This info has helped me to better understand snake activity in a temperate climate. The snakes they researched are Diadophis punctatus, Lampropeltis getulus (getula), Coluber constrictor, Heterodon platyrhinos, H. simus, Storeria occipitomaculata, Thamnophis sirtalis, Storeria dekayi, Cemophora coccinea, Tantilla coronata, and Virginia valeriae. According to their research all these snakes show very little, if any activity, from December through the end of February, with the exception of a little activity on the part of Thamnophis sirtalis.

Although these are all colubrid snakes, I know we are interested in Crotalid snakes also, and the authors did mention research on some other snakes, including Crotalus viridis, Pituophis melanoleucus, Heterodon nasicus, Thamnophis radix, Micrurus fulvius, Natrix tigrina and Elaphe quadrivirgata (in Japan), Crotalus atrox, Sistrurus catenatus, Crotalus mitchelli, and Crotalus cerastes. I know they haven’t mentioned all the snake species we might be interested in, but this is a good enough cross section to make a point about snake activity in winter. The authors have said that these and all the temperate snake species they’ve investigated, or others have studied, show seasonal activity patterns with just two possible modes of peak activity. All these snakes are relatively inactive in the winter months, with a little activity possible due to some little tested reasons, with T. sirtalis and M. fulvius being possible exceptions, and in some areas might be active year ‘round. They are saying these snakes are mostly inactive in winter. (A possible problem here is that they are researching in S. C. and the results might not apply in s. CA, s. AZ, s. TX, or FL.)

I would also like to quote the summation by the authors of the article on activity patterns from p. 403-404.

“Summary. Two distinct patterns of species-specific annual activity can be identified in Temperate Zone snakes.
1. Unimodal: A single peak of activity sometime between late spring and later summer (e.g. Cemophora coccinea).
2. Bimodal: A peak of activity in the spring and another in autumn (e.g., Heterodon platyrhinos). Although polymodal activity patterns have not been documented for any species of snake, it seems likely that some tropical species may have more than two peaks of activity in response to wet-dry cycles.

Most thoroughly studied species of Temperate Zone snakes fall into one of the above categories, and in some instances an explanation for the pattern of activity has been suggested. An additional categorization is that some species are active throughout the year (continuous) when temperatures are warm enough (e.g., T. sirtalis), whereas other species appear to be endogenously inactive during the cooler months, even during warm spells (e.g., C. coccinea). No information is available to determine whether the seasonal activity peaks of snakes in the former category shift in response to differences in the temperature regime from year to year.”

What I’ve learned this week from studying the article and from forum posts is that some snakes are never active in winter, some lightly active during appropriate warm times, and some are continuously active providing the climatic conditions allow activity of their biological functions. Unfortunately, only two snakes were mentioned in the article as being in the continuous activity category, so there is much for some of us to learn about which species have continuous activity in winter, and what functions they can be carrying out. Those of you who have already done research and produced some data could possibly add to the literature someday.

From what I could gather about Lampropeltis getula in S. C., they have little or no activity from Dec to end of Feb. However, in the really warm pockets of the nation I would agree that some kind of activity is probable from what others are telling me. I believe they are mostly inactive, but in s. Texas and other places, maybe they will make an appearance from time to time on some of those really nice days of winter. I also gather from the article that there are some snakes that are continuously active through the winter under appropriate conditions, but they are mostly unstudied and unidentified. Could kingsnakes be continuously active in some places? It seems some might think they fit into this category in their areas. I’d like to find out more about which species are in that “continuously active” category, and what are they actually doing in the winter months.

I’m hoping this post will help us to realize that not all snakes are active in winter, even in the best areas. I think it’s confusing to hear someone say, “Snakes are active in my state or area all winter.” It would sound better to me if one said, “Some snakes are active all winter in my State or area.” Then we could go on to tell which snake or snakes, and maybe sometimes we could state the conditions found under, or what the snake was doing. I think there’s a lot of possible behaviors for winter snakes near the surface.

Sorry for being so long. Thanks for listening if you got this far. I think this is an area of herpetology that needs to be developed a lot more. I’m going to take a new attitude into the field this December and see what I can come up with. I hope the literature is wrong, and I’m wrong, and there will be lots of snake species active this winter. Herping obviously would be better if you could do it year ‘round. So anyway, the big question for me now is, “Which are the snakes that are adapted for year ‘round activity?” I’d like to find a few I can study and maybe produce some data on, as far as their activities, and what they are actually doing in winter. Later….

TC

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Ratsnake Haven...researching ratsnakes since 1988

Ratsnake Haven Group...an information providing list site.

First off Terry you continue to present yourself as a gentleman unlike myself who gets to emotional or to lazy to hide my attitude

Anyway nice post. The thing to realize is some snakes take advantage of hot spots on rocks to elevate their temps to afford them the opportunity to be active. The next thing to realize is that somehow our scientific community has until recently managed to miss this occurrence. I hate to encourage FR but his point about the seasonal time frames that researchers are available seems to be more accurate than we would like. LOL The last thing to think about is what we think of as temp zones for activity might be way off.

For instance I had the honor of seeing a ridge nose in the wild 2 summers ago on a snake trip. This wonderful little snake was preceded by a pyro about 3 minutes earlier. Why this is of interest is that the air temps and ground temps where both below the "active temps" that I was told. It was in the mid forties for the air temps and the road was in the low fifties. To make it more noteworthy the pyro had just eaten two sceloperous(sp) and was still swallowing the second when I found him. It was at night in a rain storm and the rain seemed to be cooling things even more. I would have turned around and went home before I found these but I was on vacation and I figured why wait in the hotel?

As far as actual winter time activity I only have conversations and talks to quote from. I have heard of Atrox being very active in winter from a few sources. Apparently the dens they choose get heated much more than we think and they are able to get their body temps up even when the air temps are in the 40's. I could give you Florida stories but that is not what you are looking for. Hopefully a actual biologist with field experience will see this thread and maybe he/she will have actual data to contribute.

Later Jason

Thanks for the response, Jason. Interesting info about the pyro and ridgenose and temps. If pyros were active in the Dec to Feb time period that would be too much for me, but I'd be interested in knowing if anyone has seen the montane rattlers during this time frame. It doesn't matter about the researchers to me. I assumed we were talking about something they weren't into. The Savannah River study was done year 'round, however, and they did find some snakes in winter, just not much activity.

I know the diamondbacks are very opportunistic. I'm sure they take advantage of warm spells as well as many other snakes (colubrids). Someday I'll study them better and find out more about the idea of "continuous activity", snakes that don't shut down at all.

Your input is appreciated.

Good night

TC

PS: Thanks for the compliment.

AWEsome green, Terry! Well, as stated before, I'm from a semi-tropical zone, and I would almost bet that the indies, (known to breed in Sept.-Oct.) are filling their bellies to produce the very large eggs they are known for. I hear tell the males battle viciously for dominence, and would bet that basking and feeding would promote healing for the contestants. I haven't witnessed the combats but have seen many road kills down US 77 south of Kingsville every year. My group is basking in the winter months, so until I can see what they are doing with this solar energy, it's all speculation on my part. As for the kings down here, I seem to have the best luck finding yearlings on the crawl on dirt roads near the beach. The climate has a huge part in this, as they are my indicators of the coming spring. But I consistenly find them in late Jan.- early Feb. It sounds alien to people from northern climes but it is the norm down here. It is consistently warmer near the coast in winter and cooler in the summer than the surrounding areas. Gulf coast ribbon snqkes and western glass lizards are the main source of food for the island kings and are out in abundance also. I don't see the Mexican milks out till late spring so there's the wrench in the spokes, lol! They are nocturnal, though and are found mostly in the dunes. Western coachwhips are on the prowl and I can only see that as hunting, as they are sight feeders, and what would they be hunting? Herps! Anyway, great thread, and just a view from north of the border. I hope you make it down some day and John and I will show you what we know! Oh yeah, here's a five lined skink caught in Jan. 90 miles north of me. Same day produced cottonmouth and the speck. Check out the breeding colors on his cheeks! Go figure!
Todd Hughes

Haha, Todd, I'm getting Southernized...LOL. Here in the north we say getting "winterized", or ready for winter. There's a lot of preparations. "Southernized" is not having to get ready for winter, but just doing what comes natural. I'm learning, now I just have to do it

Thanks for the comp on the green. Caught that girl roaming across the road in the Ritas last summer. What FR said about them being winter active has really got my attention. I'm entertaining that thought and I'm thinking it's very possible. I could study that species year 'round. Now I just have to get in the field and get some data. I like the fact I can get in the field when noone else is doing that...haha. Do you feel that way about s. TX? Are there herpers coming down to your area in winter?

Indigos..another great species. They may be eating in winter and growing those eggs, but could probably do that w/o eating. Should be fairly easy to do a study on those I'd be willing to discuss some options and what's going on with those with ya. I'm thinking I'll have to give you a call one of these days. Private email coming later.

I understand about the coastal climate. We have what we call "lake affect" here in n. MI. The water of the Great Lakes keeps in environment near it warmer in Fall and cooler in spring. We usually don't get frost, where I work on L. Huron, until about Halloween. This same affect is probably influencing the Brazos Island ratsnakes too. Maybe that's why I had trouble with them at first. The babies couldn't stand any kind of cooling and I actually lost one the first winter. I'm thinking they probably can go year 'round and breed with no brumation, etc. I have yet to test that idea, as next year will be the first for them being adults.

Keep all those winter notes coming, Todd. I love it. More later

Terry

Hey Terry great looking Brazos! I don't see any herpers down here. I guess this is a lonely sport! Yeah, I hope to get into the Huachacas and Ritas and Chiricahuas some day for green rats and mountain kings. There are some great snakes in Ariz. and New Mex. Some day, but Texas is a big state! Looking forward to the email, but aol is being freaky last night and today.
Todd Hughes

Thanks. I'll get on that email soon. Very busy at work right now and with domestic stuff. AZ is a cool place. More later...

Terry

Snakes - and people - are active when conditions permit them to be active.

Ever gone camping without a strong light? All activity ceased at dusk, due to lack of light & cooler temperatures. But if you had been back in your home, with access to heat & light, you might have been active for hours longer.

Same with reptiles. In southern ranges, many types of reptiles have been seen active in warmer times of winter. (There are rare instances of Painted Turtles being seen swimming under ice. Here in the Northwest, I've heard frogs croak EVERY month of the year!)

True also for estivation. Many tortoises will estivate in their burrows during the hottest summer weeks, with little activity. But if temperatures cool down, they immediately become active again.

True, conditioning, especially for hundreds of years, will have an impact on behavior. Creatures accustomed to hibernating will have a natural urge to do so when temperatures drop. But, take them to a southern region with more light & warm temperatures and I'll bet that you'd see them active most of the year.

I think that the Hibernation/Estivation process is more due to point-in-time factors of light & temperature than biologically programmed, long-term behavior.

Wow, that's a great theory.

Sorry I'm so slow answering, but I just ran out of available time. I wish I had an hour here, but have to go back to work (in another county). I know we're going to say more about your theory. I love it because it brings out some great points. I don't have the experience in the warm weather climates to answer in detail, but I have a lot of experience raising snakes from many different climates. We'll talk about behavior more later, learned and instinctive. Sounds like a great subject to get into.

Thanks for the post.

TC

>>Snakes - and people - are active when conditions permit them to be active.
>>
>>Ever gone camping without a strong light? All activity ceased at dusk, due to lack of light & cooler temperatures. But if you had been back in your home, with access to heat & light, you might have been active for hours longer.
>>
>>Same with reptiles. In southern ranges, many types of reptiles have been seen active in warmer times of winter. (There are rare instances of Painted Turtles being seen swimming under ice. Here in the Northwest, I've heard frogs croak EVERY month of the year!)
>>
>>True also for estivation. Many tortoises will estivate in their burrows during the hottest summer weeks, with little activity. But if temperatures cool down, they immediately become active again.
>>
>>True, conditioning, especially for hundreds of years, will have an impact on behavior. Creatures accustomed to hibernating will have a natural urge to do so when temperatures drop. But, take them to a southern region with more light & warm temperatures and I'll bet that you'd see them active most of the year.
>>
>>I think that the Hibernation/Estivation process is more due to point-in-time factors of light & temperature than biologically programmed, long-term behavior.

Snakes - and people - are active when conditions permit them to be active.

Ever gone camping without a strong light? All activity ceased at dusk, due to lack of light & cooler temperatures. But if you had been back in your home, with access to heat & light, you might have been active for hours longer.

Same with reptiles. In southern ranges, many types of reptiles have been seen active in warmer times of winter. (There are rare instances of Painted Turtles being seen swimming under ice. Here in the Northwest, I've heard frogs croak EVERY month of the year!)

True, but not always true. I believe that some snakes and other herps truly “turn off” in the colder months, depending on species and individual needs in the species. Once colder weather hits our area in MI, nights in the 30’s or low 40’s consistently, sometime in September, most of our snakes disappear until the following spring. Question then is, “What are they doing underground?” I’m sure there’s a certain amount of activity we don’t see, but I don’t see snakes on the surface again, except for the occasional garter snake, until next season. I know this isn’t the same thing happening in all areas of the country, but the point is the snakes can shut down when they need to and are adapted to reduced activity, in some instances, for up to seven months, from observations I’ve made.

Some herps are seen in the winter months, of course. I know someone in New England that sees herps year ‘round, including snakes, in mild winters. Some snakes and many other herps will have year ‘round, or “continuous”, activity if conditions allow them. Your example of the painted turtle is a good one. We have painted turtles here too and I’ve seen them swimming or crawling before under the ice. I’ve also seen frogs before through the ice and salamanders. Amphibians are active year ‘round in many areas of the country. I’m still hearing frogs croaking in the woods here, and they won’t stop until it’s so cold they can’t move. That doesn’t necessarily mean they’re actively feeding, however. I think we need to stick to snakes, because other herps may be adapted differently. Also, we need to consider different species of snakes, because they may have different adaptations for cold conditions.

True also for estivation. Many tortoises will estivate in their burrows during the hottest summer weeks, with little activity. But if temperatures cool down, they immediately become active again.

Nice example. Question is, “Do they have reduced activity while aestivating, or are they still very active, just out of sight?” The point about hibernation/aestivation is that the herps become inactive, as opposed to regular activity. They are two different things, but I think with each there is some reduction in activity, depending on species, of course. Just like with hibernation, or brumation, if you will, some snakes shut down except for minimal life functions while they’re aestivating, others do not. There are some species that can go for months during hot weather w/o eating. It is a rest time for them. There’s got to be some activity, however, because they have to do things like lay their eggs. Maybe we should also ask the question, “How do snakes get their rest?”

True, conditioning, especially for hundreds of years, will have an impact on behavior. Creatures accustomed to hibernating will have a natural urge to do so when temperatures drop. But, take them to a southern region with more light & warm temperatures and I'll bet that you'd see them active most of the year.

I think that the Hibernation/Estivation process is more due to point-in-time factors of light & temperature than biologically programmed, long-term behavior.

I’m going to get the chance to investigate that idea in a few years when we retire to AZ. I’ve already learned a few things. Snakes have instinctive and learned behaviors. For instance, neonate snakes can be kept active year ‘round in many instances, even when their parents have been brumating for months. This is not always true, however, as we know in the hobby. Sometimes we have to cool a baby for awhile and bring it out before we can get it to eat. But with many snakes, babies can be kept active continuously until they are breeding age. I have kept several species, like Russian ratsnakes and E. fox snakes, that hibernate up to seven months in the wild. They have a strong instinct to brumate and quit feeding early in the year. However, over time they can become accustomed to a longer “active season” and less brumation. Is the brumation a learned behavior? Can all snakes be taught to skip brumation? I don’t think so. I think some snakes are not only programmed to brumate, but are adapted to be active and grow at certain times of the year, and it would change them too much if they deviated from that schedule.

Thanks for listening…TC

Interesting post. I have been studying and watching several snake species year round in the American southwest since the 1980's. I first became aware of wintertime activity through a kind and wiser Texas Rancher on the Pecos in 1980. Since then, I have watched and looked for snakes to be doing a lot of different things all year. What I would add to your post is that where you said some species have no winter activity, some have a little, and some have a lot is true intraspecifically, maybe more so than declaring species one way or another. A lot of winter activity depends on what individuals are doing at that given point in time. A gravid rattlesnake will spend a great deal of time out and about all winter, possibly with more above ground activity in January then in June. That same individual may not be out much the following winter season if she is not cycling. Even that, however, depends on the continuing cycle AND balance of hydration PLUS caloric intake PLUS thermal opportunity. This combo and interaction equals behavioral possibility, or maybe even dictates it. While I have spent the majority of my field time zeroed in on crotalids, I have not ignored other species. There is a lot going on "in them thar hills" while many are trying to force their captives to hibernate. Our beloved beasts are so absolutely damn good at thermoregulating that I think many herpetologists have missed the boat because "it is sunny but in the 40's." Rock and dead wood are awfully good heat sinks. Herps know this way better than humans, and they use their smarts year round. I think we will see many more species active in the winter once we look.

Thanks for your interesting post. Cheers, Hugh

Thanks for your very interesting post, Hugh.

And I plan on looking. Obviously I was wrong about winter activity. Now that I believe there are snakes trying to stay active in winter I'll be looking for them. It'll take time though. I still have three more winters to put in here in MI. Most of my experience is with colubrids, but I'm interested in crotes too, just never had the opportunities you guys get. Thanks for taking the time and effort on your post.

TC