Date of Award

Spring 2020

Project Type

Thesis

Program or Major

Biological Sciences

Degree Name

Master of Science

First Advisor

Daniel R Howard

Second Advisor

Carrie L Hall

Third Advisor

Donald S Chandler

Abstract

Communication is essential in biotic systems, and signals represent information exchanged between a sender and receiver. Noise can interfere with the transmission, detection, and processing of signals, and can occur in any sensory channel. Noise can also disrupt behaviors related to foraging, predator detection and avoidance, and social interactions. Most research on the effects of noise on animal behavior has been focused on its effects on terrestrial avian species and marine mammals in an isomodal context, with data on invertebrates generally sparse. Many insects have highly adapted structures for sound and vibration detection, and thus make ideal models for studying noise effects on behavior. In the following experiments, I used house crickets, Acheta domesticus, to answer the following questions: 1) Do different types and durations of noise influence the daily locomotor patterns in animals? 2) Do different types and durations of noise influence decisions related to male signaling?

To assess the effects of noise in three forms (isomodal, crossmodal, and multimodal) on locomotor patterns, I first recorded cricket locomotion in an activity monitor to establish a daily pattern, with a focus on identifying peak periods of activity. Crickets were then exposed to either noise only during this peak period (intermittent) or continuously across a 24-hour period. I found that all durations and forms of noise had an effect on A. domesticus locomotion, changing not only the daily pattern of locomotion, but the magnitude as well. All three forms of noise changed when crickets were

active, and just how active they were, highlighting the importance of noise conditions in the daily behavior of this species, and potentially other species of cricket, and other taxa. Crickets may endure fitness costs due to this change in activity.

To assess the effects of noise in three forms (isomodal, crossmodal, and multimodal) on male cricket signaling behavior, male calling was first recorded over the course of four days to identify peak periods calling times and the overall temporal pattern of male display. As in the first experiment, all noise treatments changed male calling behavior in both the time of day and magnitude of calling. In Acheta domesticus, accurate reception of the male’s call by females is crucial, and mating opportunities could be missed when males change their calling behavior, as they have done here. Anthropogenic noise will only increase in the coming years, and further research is needed to understand the impact it may have on organism behavior and fitness.

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