Cross-hotspot insights
Comparative analyses across all four hotspots — phenology, guild sensitivity, harbinger stability, effort bias, and community turnover.
Cross-Site Phenological Concordance
Of 69 shared species, **84%** show concordant trends (r=0.08, p<0.001). **Sandy Creek Park** shifts are **0.2x** slower on average than **Brumley Nature Preserve**.
Weak correlation (r=0.08) suggests site-specific microclimate dominance affects phenology similarly at both sites. The 0.2x difference in shift magnitude may reflect habitat differences, urbanization gradients, or site-specific weather patterns. Concordant trends indicate species are tracking similar environmental cues across the landscape.
Guild-Level Climate Sensitivity
**Other Waterbirds** shows strongest phenological shift at Sandy Creek Park: **9.49 days/year** (advancing). Based on **1 species**. **1** species advancing, **0** delaying.
Most guilds show advancing phenology, consistent with warming spring temperatures. Differences in shift magnitude reflect guild-specific migration cues (photoperiod vs temperature) and trophic dependencies. Long-distance migrants may show weaker responses than short-distance migrants. Resident species may shift breeding phenology rather than arrival timing.
Observer Effort Bias Quantification
**Barred Owl** shows **5-hour** peak shift when correcting for observer effort at Sandy Creek Park. Mean shift across 2 nocturnal/crepuscular species: **2.5 hours**, revealing substantial observer bias in raw counts.
Effort correction reveals moderate observer bias. Nocturnal species appear more common during typical birding hours (dawn/dusk) but peak activity occurs when fewer observers are present. This bias affects ecological interpretations of habitat use, activity patterns, and detection probabilities. Effort-corrected rates provide more accurate estimates of true species detectability.
Cross-Site Beta Diversity
**176** species shared between **Sandy Creek Park** (180 total) and **Flat River Waterfowl Impoundment** (213 total). Sørensen similarity: **0.90** (90% overlap). **4** species unique to Sandy Creek Park, **37** unique to Flat River Waterfowl Impoundment.
High similarity suggests similar habitat types and regional species pool. Flat River Waterfowl Impoundment supports more unique species, suggesting greater habitat diversity. Shared species represent core regional avifauna.