Behavioral decisions in sensory landscapes: crayfish use chemical signals to make habitat use choices

Abstract

Animals make many ecological decisions such as foraging, mating, and avoiding predators based on the information they extract from the sensory cues in their environment. Environmental stimuli which include the information animals use for decision making can be called a sensory landscape. To investigate ecological decision making in complex sensory landscapes, we presented a crayfish with a choice of resource rich and resource poor habitats under different simulated predatory conditions within a Y-maze setting. A simulated predation event (alarm odor) was alternately placed in either the resource rich or poor habitat to observe the impact of the predation event on the habitat choice and use. Habitats consisted of multiple food resources, multiple shelter resources or combined food and shelter resources. Trials were videotaped and crayfish behavior was analyzed for time spent in each habitat under different predatory and resource conditions. Results show that crayfish avoided the location of alarm odors, regardless of resource presence. Resource preference of crayfish differed among resources depending on the alarm odor location. Female and male crayfish made different decisions based on resource type and alarm odor location. Information from the crayfish’s sensory landscape drives the decision making of crayfish. Researchers need to understand the sensory environment of an animal in order to make the most accurate prediction on an animal’s decision making and behavior. We suggest using a sensory landscape model, because organisms use the entire umwelt of stimuli to guide their decision on habitat and resource use.