On Bullfrog Pond

I drive to the natural area one summer morning and find seven police cars blocking the entrance. I return home and send a message to the woman heading up my citizen-science project, studying bullfrogs. Two days later she responds about an attempted murder that “probably won’t affect you.” She signs her email with a smiley face.

A friend married to a police officer tells me the area is notorious for daytime rapes. I go alone in the morning several times a week. I invite excited friends to go with me. I recruit my hapless husband. Anything to avoid being alone. The only time I encounter a ranger patrolling he asks me with suspicion what I’m doing.

A man wandering into the brush surrounding the pond is close enough for me to see the needle punctures and scarred veins on his legs. He disappears, and then, after a few minutes, reappears. Maybe he’s clean, but the random cars idling in the parking lot in the late evening along with the area’s reputation make me suspicious of drug activity.

The weeds that grow up to my chin and trigger my hay fever and the trash people throw into the pond in increasing amounts are irritations compared to these encounters, but still bothersome.

Twenty or thirty volunteers participated in the training, but all summer I see only three other names on the check-in sheet and these names rarely show up; one of these individuals signs in only once. Could the lack of enthusiasm be because the natural area is creepy if not downright scary?

All last summer, I scribbled notes and filled in data sheets. I mistook algae bloom for eggs. I conscientiously tried to fulfill what soon became the Sisyphean task of counting the rapidly proliferating frogs. Five sit on a log, the next night seven, the next nineteen. Soon I cannot count them. I begin to understand why frogs were a Biblical plague and what it would mean to have the Nile “teem with frogs” that appeared even in the kneading troughs. They had to be bullfrogs.

The study I participated in required charting the ascendance of bullfrogs, an invasive species in northeastern Colorado that competes with native species. One story is that the frogs were accidentally introduced in the early 1900s while an agency was stocking trout. Another story is that the Colorado Department of Wildlife along with commercial meat producers intentionally introduced them as a sport species to be hunted. With a fishing license, giggers may cull an unlimited number.

Although adults may fondly remember childhood experiences catching them in ditches and ponds, bullfrogs are a problem in Colorado. They spread diseases to native frogs that they themselves are immune to, and as their population rises, the native species decline. Bullfrogs, which can measure 3 to 6 inches in the body, with their legs adding another 7 to 10 inches, also eat the eggs and tadpoles of other frog species in addition to devouring the adults, which are much smaller than the bullfrogs.

What keeps me going are the water snakes, the deer, the giant turtle, the foxes hunting grasshoppers in a neighboring field, and the leopard frogs whose call sounds like someone chafing a rubber balloon. The project is rewarding in these unexpected ways, but I am ready to end my commitment as soon as possible.