Crickets in Context: How Environment and Morph Relate to Locomotory Behavior.

One challenge faced by animal behavior researchers is that behavior observed and studied in captivity may not reflect behavior in nature, but rarely are both contexts assessed. Pacific field crickets encounter an acoustically hunting lethal parasitoid fly in Hawaii, which has facilitated the rise of novel male morphs, like "purring," that sing attenuated songs and are protected from the fly. Yet these novel morphs are still able to reproduce. It is possible that the quieter purring males use an alternative mating tactic like increased locomotory behavior to facilitate encountering mates. Using a population that contains purring males and typical ancestral males, we asked if the two types differ in their locomotory behavior in the wild, whether this result is maintained in the lab, and whether behavior depends on context (varying the test substrate: natural grass or artificial). In the wild, the two male morphs did not differ in the time spent walking on the grass, but ancestral males spent more time under the grass. In the lab, the two morphs spent the same amount of time moving but traveled significantly further and faster on the artificial substrate than on the grass. Unlike in the field, morphs did not differ in movement under the grass in the lab, which is interesting as crickets are subject to parasitism in the field and may be protected under the grass. Our findings highlight the value of pairing lab experiments with field observations to fully understand animal behavior.