Date of Award

1-1-2018

Document Type

Thesis

Degree Name

M.S.

Department

Biological Sciences

First Advisor

Robin M. Tinghitella

Abstract

When environments change rapidly, adaptive phenotypic plasticity can ameliorate negative effects of environmental change on survival and reproduction. Recent evidence, however, suggests that plastic responses to human induced environmental change are often maladaptive or insufficient to overcome novel selection pressures. Anthropogenic noise is a ubiquitous and expanding disturbance with demonstrated effects on fitness-related traits of animals like stress responses, foraging, vigilance, and pairing success. Elucidating the lifetime fitness effects of noise has been challenging because long-lived vertebrate systems are typically studied in this context. In both chapters described herein, I reared field crickets, Teleogryllus oceanicus, in masking traffic noise, traffic noise from which we removed frequencies that spectrally overlap with the crickets' mate location song (non-masking), or silence. In chapter 1, I tested female mate location ability at reproductive maturity under one of the same three acoustic conditions (masking, non-masking, silence). We found that exposure to noise during rearing hindered female location of mates, regardless of the acoustic environment at testing. Females reared in masking noise took 80% longer than females reared in silence to locate a simulated singing male who was <1m away. In chapter 2, I follow noise stressed invertebrates throughout their lives, assessing a comprehensive suite of life history traits, and ultimately, lifetime number of surviving offspring, for the first time. I found that exposure to noise extended development time (delaying maturity) and reduced adult lifespan; crickets exposed to masking noise spent 23% more time in juvenile stages and 13% less time as reproductive adults than those exposed to no traffic noise. Chronic lifetime exposure to noise, however, did not affect lifetime reproductive output (number of eggs or surviving offspring), perhaps because mating provided females a substantial longevity benefit. Impaired mate location ability and changed life histories can be added to a growing list of fitness costs associated with anthropogenic noise, alongside reductions in pairing success, nesting success, and offspring survival. I encourage researchers to consider effects of anthropogenic disturbances on growth, survival, and reproductive traits simultaneously because plastic responses of different traits are likely to amplify or nullify one another, influencing fitness.

Provenance

Recieved from ProQuest

Rights holder

Gabrielle A. Gurule-Small

File size

55 p.

File format

application/pdf

Language

en

Discipline

Behavioral sciences, Conservation biology, Evolution & development

Share

COinS