Sensory Traps, Imprinting, and Cross-contextual Learning: Can Shifting Food Preferences Alter Patterns of Mate Choice?

University Of Florida, Gainesville FL

Investigators

Abstract

Understanding how biodiversity evolves, and in particular, how sudden environmental changes can lead to rapid responsive changes in plants and animals is an important challenge in biology. This study examines a simple, yet novel, hypothesis to explain why so many animals have evolved elaborate and seemingly arbitrary traits and colors that they display to prospective mates during courtship. This project uses ideas from multiple fields of biology and psychology to test the idea that preferences learned in one context (such as a preference that an animal learns for a specific color of food) can affect the formation of preferences in another context (such as a preference for that same color when choosing a mate). These ideas will be tested in two species of jumping spiders: a Kenyan species that eats female mosquitoes (specifically, the vector of human malaria) where red colored food is preferred and an American species that feeds on many agricultural pests and where red colored food is avoided. Work will alter female food color preference and then determine how this impacts the colors that females look for in mates. Both of these species play critical roles in their respective food webs; understanding how their populations respond to changes in prey have important implications for human health and agriculture. The study will engage several undergraduate student researchers, who will learn the scientific process through hands-on experience. In addition, it will fund the participation of several non-science majors at a local community college to improve scientific literacy among future leaders in other fields (e.g., politics, business, education). In addition to traditional scientific publication, the team will also disseminate findings in a collaborative art exhibit entitled Arachnophilia (to take place in both the US and Kenya). Despite nearly 150 years of research to understand the mechanisms that drive the evolution of elaborate male ornamental traits biologists frequently stumble upon puzzling patterns in nature that challenge existing theory (e.g., yearly fluctuations in mate preferences, unexpected patterns of geographic variation in ornamentation and preference, and the presence of seemingly arbitrary ornaments). Clearly, the current theory falls short of fully explaining the complexity in nature. This study integrates ideas from across three distinct paradigms in animal behavior (sensory traps, sexual imprinting, and cross-contextual learning). It proposes a novel mechanism for the rapid evolution of male display traits: that an individual cannibalistic female's recent experiences with colorful food will shape how she interprets a male's colorful courtship display. Despite its simplicity, this idea could explain broad patterns of diversification and be applicable to a wide range of taxa. Using correlational field studies and manipulative lab experiments, this idea will be tested in two jumping spider species: Evarcha culicivora (a specialist on Anopheles mosquitoes in Kenya) and Habronattus pyrrithrix (a generalist predator from the southwestern USA). This study involves reversing the prey color preferences of these two species by exposing them to different types of naturally-occurring colorful foods and evaluating subsequent effects on mate preferences. This study capitalizes on the charismatic courtship displays of male jumping spiders to creatively link research, science education, and outreach. Work will be carried out by teams of undergraduate researchers (including non-science majors at a community college) and will be disseminated through a collaborative art exhibit.