Do Green Lynx Spiders (Peucetia viridans) Change Color in Response to Their Backgrounds?

For animals that traverse patchy or dynamic backgrounds, morphological color change can help to stay hidden from predators and prey. The green lynx spider (Peucetia viridans) is a sit-and-wait predator that hunts pollinators and other insects among vegetation. In the field, it is often bright green with variable patterns of white, red, orange, yellow, and purple, and individuals often appear well-matched to their backgrounds. A previous study that relied on human observers to assess color suggested these spiders can shift their body colors to match their surroundings. Our goal was to replicate this work using modern reflectance spectrophotometry to quantify spider colors. Across two experiments (in different years), we collected adult female spiders and assigned them to three differently colored backgrounds in the lab. Unexpectedly, we found little evidence that the spiders in our study shifted their colors to match their backgrounds. However, exploratory analyses revealed that color change did occur, just not as expected, and was likely related to senescence, diet, body condition, or some combination. We discuss these findings in the context of previous work and suggest that the complex nature of color change in this species makes it a promising candidate to provide novel insights for the field.