Date of Award

Fall 2024

Project Type

Thesis

Program or Major

Genetics

Degree Name

Master of Science

First Advisor

Adrienne Kovach

Second Advisor

W. Kelley Thomas

Third Advisor

Michael Kinnison

Abstract

Animal diet studies provide valuable insights into evolution and ecology, including about niches filled by species and how they are shaped by interspecific competition. Fecal DNA metabarcoding is an efficient, non-invasive approach to assess animal diets by sequencing DNA recovered from fecal samples. This study used fecal DNA metabarcoding to characterize the breeding season diets of six Atlantic coast tidal marsh sparrow species with varying levels of adaptation to tidal salt marsh habitat. We identified the major prey taxa present in each species’ diet, compared dietary diversity as a measure of niche width across species of varying salt marsh specialization, and evaluated evidence for interspecific competition where sparrow species occur in sympatry. We identified prominent prey items in the six tidal marsh sparrow species’ diets and found significant differences in diet composition and diversity among species, potentially associated with levels of adaptation to salt marsh habitats. We also found that closely related Ammospiza sparrow species had lower dietary diversity on sympatric compared to allopatric sites, suggestive of niche shifting due to interspecific competition. These findings further understanding of diet adaptation to tidal marsh habitats in sparrow species and provide a case study of using dietary niche analyses to study species evolution and ecology.

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