Eastern Meadowlark migration, nest success, and response to land use change in Illinois

Grassland birds have been undergoing severe population declines for decades, with habitat loss often being credited for these declines. Eastern Meadowlarks (Sturnella magna) are one of the most rapidly disappearing bird species in North America, having declined by 75% in 50 years. The first chapter of my research investigated where meadowlarks overwinter using archival GPS tags, breeding site fidelity, and factors impacting nest survival. I observed low return rates (15.8%) and found that female meadowlarks in central Illinois migrate to the southern United States (southern Tennessee, southern Mississippi). These results suggest Eastern Meadowlarks are either selecting different breeding grounds or have low return rates due to poor overwinter survival. Nest survival was most influenced by stage (i.e., egg or nestling), with predation occurring more frequently during incubation. Nests were most often oriented to the northeast, presumably to avoid prevailing winds from the southwest. Further research on meadowlark overwinter survival is needed, likely using satellite transmitters due to their low return rates. My second chapter analyzed the spatial and temporal relationships between land cover and the abundance of three grassland bird species along USGS Breeding Bird Survey (BBS) routes. Eastern Meadowlarks and Grasshopper Sparrows (Ammodramus savannarum) displayed lower abundance in areas with greater forest cover and increased with greater grass cover. Dickcissels (Spiza americana) exhibited negative relationships with all land cover types, suggesting they are more abundant in habitats with greater diversity. Temporal models showed meadowlarks to decline in areas with increasing corn, but increase with increases in grassland and development. Grasshopper Sparrow populations also increased with increasing development. Dickcissel numbers declined as corn, soy, and grassland increased. More research with higher-resolution land cover data is necessary to further understand how land cover impacts avian populations.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Natural Res & Env Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Bozzo, Julianne M

Contributors dc:contributor

• Ward, Michael P
• Benson, Thomas J
• Herkert, James R
• VanBeek, Kelly R

• Grassland Birds
• Land Cover
• Archival Gps Tags
• Migration, Sturnella Magna
• Spiza Americana
• Ammodramus Savannarum

Statement dc:rights

• Copyright 2023 Julianne M. Bozzo

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/120183

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F120183