Year of the Kingsnake: My Best California Kingsnake Field Season Yet!

Being one of the greatest reptile and amphibian diversity hotspots in the United States, California offers a wide range of treasures for the field herpetologist to find. One of the most iconic members of the California herpetofauna is the California Kingsnake (Lampropeltis getula), a nonvenomous colubrid snake that is found throughout most of California, as well as parts of Nevada, Arizona, and Northwestern Mexico. Throughout its range, the California Kingsnake displays great variation in pattern and color, some of which is genetics based and some of which is environmentally determined. Most individuals have a banded pattern with alternating dark and light colored bands, but the width of the bands and color can vary wildly between individual snakes. Some have narrow light bands, while others have wide light bands. Some are black and white, while others are yellow and brown. It is also not uncommon for California Kingsnakes to have incomplete bands or chainlink bands, introducing even more variation in the pattern. The markings on top of the head also vary between individuals. Some populations also have darker faces and darker light bands than normal, often being referred to as mud morphs. But perhaps the most extreme form of pattern variation in the California Kingsnake is the striped and scrambled morphs that are found in Southern California, where the typical banded pattern is replaced with either a dorsal stripe, a mottled pattern, or a combination of the two. All of this phenotypic variation makes the California Kingsnake one of the most visually variable snakes in the world, and it is no wonder that countless field herpetologists have journeyed out to California to find this beautiful snake.

But it is not just looks that makes the California Kingsnake awesome. It also has an amazing life history. Most people are probably familiar with the kingsnake’s habit of occasionally hunting and eating rattlesnakes, and this is certainly impressive. It is immune to rattlesnake venom and kills its prey by biting the head and then constricting it until the prey dies of asphyxiation. But rattlesnakes are not the only prey items the California Kingsnake eats. Just as often, it feeds on rodents and lizards, making the California Kingsnake an important secondary consumer in the ecosystems where it occurs. But the most interesting part of the California Kingsnake’s life history has to be its secretive, often subterranean nature. While its habits vary between habitat types, the California Kingsnake spends much of its time underground in animal burrows and natural cracks in the soil, and the degree to which it can do so is mind boggling. If the burrow network is large enough, a California Kingsnake can rest, find food, cool off or warm up, keep its skin moist, and possibly even find a mate without ever coming above ground. Because of this, some experts estimate that a single California Kingsnake may spend as little as just two weeks worth of time above ground during an average rain year. During a drought year, that time could shrink down to only a few days. Some populations of California Kingsnakes spend more time moving above ground than others, but even these populations likely do not stay active above ground more than a few weeks a year. The California Kingsnake is also very sensitive to changes in ground moisture and air humidity, preferring to be active during moderately humid weather. As a result, it is active above ground less frequently than other snake species in the same ecosystem and is seldom seen.

However, there are some methods for increasing the probability of finding this snake. In desert habitats, driving roads at night during warm, humid weather is the best bet, but there is still no guarantee of seeing California Kingsnakes this way. The most productive method for finding this species is to place pieces of plywood (called coverboards) over vole and mouse burrows in the California grasslands and then checking underneath the plywood for any snakes that might be hiding there during the warm, relatively humid spring months (Late February through April most years). Called board flipping, this strategy works great for finding this species because well-placed coverboards can both create a moist microclimate underneath that the kingsnakes like and persuade the kingsnakes to thermoregulate under the coverboard instead of inside a burrow (the snakes still think they are underground). When the conditions are right, a site with many well-placed coverboards can reveal several California Kingsnakes in a day, making it possible to not just see the snakes but learn more about their local densities and movement patterns as well.

I have been actively searching for California Kingsnakes since the spring of 2019 and not only have I seen a good number of these incredible snakes, but I have also learned a lot about their life histories. However, this helping season, the spring of 2023, has been by far the most rewarding kingsnake field season I have had. For starters, I found 15 individual California Kingsnakes this year alone, by far the most I have ever seen in one year. Several of these snakes had unusual patterns, such as a bright brown and yellow banded morph I found in San Diego County, CA and a banded morph from Los Angeles County, CA with atypically wide and white light bands. Others were just overall spectacular snakes, such as a large banded morph I got to see on a field survey in Ventura County, CA. I also got to experience two "perfect" days for looking for snakes, those days when the conditions are perfect, the timing is right, and you end up finding a lot of snakes. The first was on April 2nd, when I found the first 3 California Kingsnakes of the year at boad line with 20-24 boards. In addition to the kingsnakes, I also found 4 Gophersnakes and 4 Ringneck Snakes, meaning that I was finding snakes at a rate of one under every other board, something that I had never done before. It is Southern California snaking at its finest. The second perfect day was April 13th, where I was able to find 6 kingsnakes in one day, beating my record for most seen in one day.

But the most rewarding California Kingsnake observations of the year were personal discoveries I made. The first of these was finding a hatchling in shed under a coverboard I placed a year and a half earlier in Santa Barbara County, CA. While the in-shed snake was not much to look at, I was still so excited to see it, as this was the first time I had found a California Kingsnake under a board that I had placed. I have found snakes under my own coverboards before, but never a kingsnake, as they are more particular about the moisture under the board and the placement of the board over rodent burrows. I also learned a lot about above-ground kingsnake movement thanks to one board line in particular, where I was able to find 7 of the 15 kingsnakes I saw this year. Three of these kingsnakes I found on multiple occasions, with each one being easily identified by its pattern. It is not unusual to find the same snake again when visiting a board line multiple times in a season, but it is unusual to find the same snake under different boards, or so I thought. All three of the kingsnakes I found multiple times this year moved to a different coverboard between encounters. What was more was that many of the boards I was finding kingsnakes under at this spot did not have holes or cracks underneath them. This meant that the kingsnakes were finding the boards by traveling above ground and were then moving considerable distances above ground to reach other boards. One individual that I found under a board with no holes was found just over a week later under another board around 200 feet away from the first board. Clearly, it had reached the board above ground. I was truly amazed to find that this snake had not only moved such a great distance, but had also done so above ground. After my experiences with the kingsnakes this year, I believe that it is likely that the California Kingsnakes in Southern California probably spend a lot more time traveling above ground than previously thought. Of course, further observations will have to be made to investigate this. But perhaps the greatest California Kingsnake find I had this year was a typical banded adult from a known board line in Ventura County, CA. While it did not look too special as far as California Kingsnakes are concerned, it is one of the most significant herpetological finds I have made in my life. To my knowledge (from talking with other field helpers and personal experience), this was the first California Kingsnake to ever be found at this site, a site where other common snakes are plentiful and the habitat looks like a California Kingsnake paradise. Being my last field day of the season, this was one heck of a way to end the spring herping season of 2023.

I will never get tired of searching for the California Kingsnake and this year has only made me more curious about the habits of this amazing species. I am sure that I will see more of this species in the future, but it is going to be hard to top the experiences I have had with the California Kingsnake in 2023.

Publicado el abril 24, 2023 11:10 TARDE por tothemax