Abstract

Florida Scrub-Jays (Aphelocoma coerulescens, FLSJ; federally Threatened) are cooperatively breeding birds endemic to Florida and dependent on fire-maintained xeric oak scrub. FLSJs are year-round residents, highly territorial, and rarely disperse far from their natal territory. Lifetime reproductive success is highest among individuals breeding in early-successional habitat, usually less than 9 to 10 years post-fire. However, because scrub burns infrequently such early-successional, high-quality habitat is extremely limited and competition for it as breeding space is likely intense. Because some birds live long enough to experience habitat succession, FLSJs also occupy later-successional overgrown scrub, even though both survival and fecundity decline. Although immigration rates into later-successional habitat decline, some birds settle there, perhaps to avoid competition. Prior to dispersal into new breeding territories, most non-breeders engage in pre-dispersal forays, which occur before and immediately after the breeding season. Because FLSJ territories occur across a gradient of post-fire succession, and young birds make frequent forays beyond their natal territories, and are highly visible while doing so, they are ideal models to test how individual and environmental factors drive habitat preference when exploring a post-fire mosaic. I investigated how individual behavioral phenotype, natal territory condition, and body condition relative to conspecifics influence extra-territorial foray behavior across a habitat mosaic that includes various time-since-fire (TSF) intervals. My study system was a population of individually marked FLSJs on 1,214-ha of managed scrub at Archbold Biological Station (Highlands County, Florida). I measured off-territory movements of 114 yearling birds in three annual cohorts and quantified habitat preference using fine-scale fire history records. These data, paired with behavioral assays and morphometric records for each individual FLSJ, allowed me to create and compare models of exploratory behavior underlying searching patterns during pre-breeding forays. My results indicate significant variation in habitat preference by individual FLSJs during forays, driven by an individual's behavioral phenotype and the TSF of its natal territory.

Graduation Date

2019

Semester

Fall

Advisor

Bohlen, Patrick

Degree

Master of Science (M.S.)

College

College of Sciences

Department

Biology

Degree Program

Biology

Format

application/pdf

Identifier

CFE0007864

URL

http://purl.fcla.edu/fcla/etd/CFE0007864

Language

English

Release Date

12-15-2022

Length of Campus-only Access

3 years

Access Status

Masters Thesis (Campus-only Access)

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