A Cool Snake: The Western Yellow-bellied Racer

June 5th, 2024

Each day I spend on the mitigation lands is a lesson in observation. The three main habitats—grasslands, riparian corridors, and wetlands—are filled out by beautiful oak and ash woodlands. There is always something new and surprising to encounter. Yesterday, my colleagues Jake, Robert, and I visited our northern wetland area to help move some cows to different grazing pastures. Jake heard a sound moving through the tall grass we were walking through, and we all stopped to find what was moving so steadily. It turned out to be a large western yellow-bellied racer snake (Coluber constrictor mormon). This is a subspecies of the eastern racer and is a nonvenomous snake. We did not see any aggressive behavior from this snake, even after we picked him up to photograph.

The racer snake we encountered was unlike any I had seen before, both in its girth and length. Though the western subspecies rarely gets longer than 1 meter, the eastern species can grow to a staggering 2 meters long. The individuals I have previously encountered were small, slender, and true to their name, swift in their movements. This snake can reach a speed of seven kilometers per hour and its territory ranges out about 1 kilometer from its den. Its unique physical characteristics, such as its impressive length and speed, make it a fascinating creature to study.

The adult yellow-bellied racer is brown to olive-green above and pale yellowish below, but the juveniles look completely different. They have dark blotches on the side and many dark blotches on the back. They look similar to gopher snakes, except the racer has large dark eyes and a long, unmarked, pointy tail. I have never seen a juvenile racer (or perhaps I have seen one but mistook it for a gopher snake).

Western Racers are diurnal, which means that they are out during the day. They eat lizards, small mammals, birds, eggs, other snakes (even their own kind), small turtles, and large insects. I wonder if they eat praying mantises. We have a lot of those! They hunt by holding their head high off the ground and swinging it back and forth. Being able to climb trees probably aids them in their pursuit of birds and eggs. Understanding their hunting habits gives us a deeper insight into their ecological role and behavior.

Another interesting fact about the western yellow-bellied racer is that it has been found denning in winter with other species of snakes.

Snakes are difficult to see among the tall grasses of Willits Valley, and it is always interesting to find one as beautiful and fast as the western yellow-bellied racer.