Date of Award

January 2017

Degree Type

Open Access Thesis

Degree Name

Master of Science (MS)

Department

Biological Sciences

First Advisor

David R. Brown

Second Advisor

Gary Ritchison

Third Advisor

Stephen C. Richter

Abstract

Coastal habitats are being impacted by land development, fragmentation, and disturbance related to climate change. The remaining natural areas need to use planned management that may, in some cases, include the use of prescribed fire to maintain habitat quality. Numerous species of passerines, including some with declining populations, use the Gulf Coast as a wintering area, and some depend on habitats managed by fire. To provide information for land managers, I studied the winter bird community at Naval Live Oaks in Gulf Islands National Seashore with two primary objectives: (1) to describe the distribution, abundance, and diversity of the non-breeding winter bird community among the available habitats, and (2) to describe the distribution, abundance, home range size, foraging behavior, and spring-migration departure times of Ruby-crowned Kinglets (Regulus calendula) found in the dominant available habitats. These habitats include fire-managed areas such as longleaf pine savanna, oak scrub, and sand pine scrub. During the winters of 2013 and 2014, the bird community was surveyed with repeated fixed-area searches paired with vegetation surveys. Kinglets were banded and regularly re-sighted to record foraging behavior, map home ranges, and monitor spring departure times throughout the winter and the spring migratory period. Bird community surveys revealed differences in the abundance, distributions, and diversity between the two years and within habitats. Species richness was minimally higher in 2014 than in 2013, but overall abundance increased in all habitats. Different fire-management regimes provided varying structures of habitat that provide both high- and low-quality habitat. Habitat segregation among age/sex classes of Ruby-crowned Kinglets was apparent in some habitats. Male kinglets were on average larger than other kinglets based on structural body size. Foraging attack type varied in regards to the burn treatment, but total attack rate did not. Body size was a strong indicator of the timing of spring departure, which may explain some of the overlap between the departure times of the age/sex classes. My results provide a description of the landbird habitat use in the different available habitats of the Naval Like Oaks area of the Gulf Islands National Seashore, and suggest that fire-based management will help to maintain the current bird community structure. The current mosaic of habitats at Naval Live Oaks provides both successional gradients and ecotonal gradients that provide a wide range of habitats. The diversity of habitats provides areas for a diversity of ecological niches. Species that use predominantly pine trees (Brown-headed Nuthatches, Pine Warblers, and Eastern Bluebirds) and open habitats have the strongest responses to fire management. Kinglets also responded to changes in habitat by demonstrating differing abundances and evidence of segregation among age/sex classes, but these differences were not completely dependent on fire-based management. Suitable high quality habitats were found in both burned and unburned areas, and depended largely on available foraging substrate and the corresponding horizontal structure.

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