At one time, Mormon crickets were responsible for devouring settler’s crops in Utah. Seagulls saved the day by feasting on the crickets, later becoming Utah’s state bird in honor of their miracle. In late June, Mormon crickets, or Anabrus simplex Haldeman, are a remarkable food source for fish in Lodore Canyon. At roughly 1 1⁄2 inches in length, these crickets are a large meal for fish, birds, and anything that can get a mouth around one. We even considered dipping them in chocolate for dessert. When arriving at camp in Lodore Canyon, we immediately noticed an abundance (or infestation, depending on how you feel about bugs) of crickets on the sandbar. It seemed as if the crickets were wandering around aimlessly, eating anything that crossed their paths. Conversely, fish were waiting for the crickets to cross their paths, occasionally rising in the backwater to gulp one down. A backwater pool, roughly 6 ft deep, was bounded by a sandbar on one side and the canyon wall on the other. During high flows, fish would swim into this backwater and simply devour crickets. It seemed as if every fish in the river knew exactly what was going on and was looking for a piece of the action. In other words, it was Christmas time for these fish. In order to understand what kinds of fish were in this pool, we decided to sample using hook and line techniques, all in the name of science. No lead weight was needed for the fishing rig, as the weight of the bug was enough for a 15 ft cast. Four different fish species were caught using real and artificial Mormon crickets: channel catfish, flannelmouth sucker, brown and rainbow trout. The trout and the catfish were kept for the purposes of stomach content analysis and a tasty diner. The outer appearance of these fish indicated that they had full stomachs. One large rainbow had 11 recognizable Mormon crickets, and many more that were being digested. At our next campsite, an extremely obese Western toad was easily captured. It was obvious that this toad had too been gorging itself on Mormon crickets. Mormon crickets seem to be an important food source for many different creatures in Lodore Canyon.
Pictures showing backwater pool and flannelmouth sucker fooled by artificial cricket.
Pictures showing gut contents of rainbow trout, Mormon cricket, and obese Western toad.
