The effects of habitat color and surface temperature on habitat selection of various Melanoplus grasshopper color morphs

Abstract

Habitat selection plays a large role in the behavior of many organisms. Ectotherms are unable to produce their own internal heat and rely on environmental sources to maintain an ideal body temperature, so thermoregulation may play an important role in habitat selection. In addition, decreasing the risk of predation may also be an important factor when choosing habitats. Here, we looked at habitat selection in various color morphs of Melanoplus femurrubrum and Melanoplus sanguinipes grasshoppers to see whether thermoregulation or risk of predation determines where they spend the majority of their time. We found that male grasshoppers are significantly darker than female grasshoppers, but none of our color or predation trials revealed a significant difference in color choice. However, we did see trends that generally supported the thermoregulation hypothesis: lighter grasshoppers tended to spend more time in areas with darker backgrounds while the opposite was potentially shown to be true for darker grasshoppers. These results could have implications for the future of these species, especially in the context of the climate change -- as the earth warms, it is possible that the suitable habitat for the grasshoppers that prefer cooler substrates will decrease, which could cause a change in the composition within these species as a whole.