Date of Award
2024
Document Type
Open Access Master's Thesis
Degree Name
Master of Science in Applied Ecology (MS)
Administrative Home Department
College of Forest Resources and Environmental Science
Advisor 1
Jared Wolfe
Advisor 2
David Flaspohler
Committee Member 1
Jill Olin
Abstract
Anthropogenic activities have impacted ecosystems across the globe. However, wildlife species have exhibited heterogenous responses to these novel changes, with some species experiencing population growth, and others succumbing to population decline. I studied examples of both within the songbird taxon, focusing on drivers of range expansion in the Northern Cardinal and acoustic mitigation mechanisms for migratory bird-building collisions, a source of decline for many songbird species. I found that the Northern Cardinal’s range was primarily a function of climatic stress, which was supported by the modulation of the molt process across latitudes. Specifically, Northern Cardinals exhibited faster feather growth rates in colder climates, likely to avoid molting in adverse weather conditions. This has implications for drivers of population resilience, wherein wildlife species that exhibit life history plasticity may be imbued with greater global-change responsiveness. I also studied mortality mitigation strategies for songbird taxon experiencing population loss due to collisions with anthropogenic structures. I found that flight coordination of migratory birds could be manipulated through the projection of relevant acoustic signals. Specifically, I found that a playback of generalist songbird species acts as a migratory bird attractant and a 2-10 kHz broadband sound acts as a migratory bird deterrent, effectively directing birds away from unsafe airspace. This technology was employed at several large buildings in downtown Chicago to address high numbers of migratory bird collision mortalities. Both research projects address the nuanced manner in which anthropogenic influence has modified wildlife species population dynamics, providing insight into drivers of species resilience and new applied conservation methodologies.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Recommended Citation
Brewer, Jenna, "DIVERGENT RESPONSE TO ANTHROPOGENIC CHANGE WITHIN THE SONGBIRD TAXON: INSIGHTS FROM THE RANGE EXPANSION OF THE NORTHERN CARDINAL AND MITIGATION MECHANISMS FOR MIGRATORY BIRD-BUILDING COLLISIONS", Open Access Master's Thesis, Michigan Technological University, 2024.