Alejandra S. Martinez

Alejandra Martinez (M.S.)
Stephen F. Austin State University
Major Advisor: Jessica Glasscock, P.D.

Avian Community Dynamics WIthin A Riparian Corridor: A 12-Year Perspective

North American avifauna has declined nearly 30% since 1970 due to habitat loss, climatic change, and unidentified factors. Declines in avian populations and temporal changes in species composition are critical parameters to evaluate for the maintenance of biodiversity. Our study site is a riparian area along the Aransas River, on the Welder Wildlife Refuge, located in the Central Flyway migration corridor. We aim to examine the long-term temporal dynamics of the avian community and identify any occurrences of observed population shifts or trends. Utilizing the Monitoring Avian Productivity and Survivorship (MAPS) protocol and data, we will compare community dynamics, including species diversity, from the summers of 2007, 2008, 2009, 2021, 2022, and 2023. In addition, we aim to compare the effectiveness of three sampling methodologies in detecting complete breeding bird communities. Utilizing a multi-method modeling approach, we will compare the MAPS protocol, point count, and autonomous recording unit methodologies in terms of the time of detectability, cost-effort analysis, and species diversity and occupancy. Initial analysis of rank abundance curves (2007 – 2021) demonstrates consistency in the most abundant species, Northern Cardinal (Cardinalis cardinalis); however, they exhibited a decrease in abundance each year. Although the species diversity showed no significant difference over the years, individual species did experience shifts within their rank positions in the populations.  

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