Forest Patch Size and Connectivity Determine Breeding Bird Species Richness in Fragmented Mid-Atlantic Temperate Forests

This study investigates effects of forest patch size and landscape connectivity on breeding bird species richness in fragmented temperate forests within the context of landscape ecology and conservation ornithology, an area of growing scientific importance given its implications for conservation land acquisition prioritization and forest patch minimum size standards for landscape planning. Using standardized point count surveys with 100-m fixed radius at 3 visits per season combined with GIS-derived landscape metrics, we examine area-dependent minimum viable territory requirements for interior-forest species excluding them from small patches in 48 forest patches across 6 landscape sectors spanning 3 states (Maryland, Pennsylvania, Delaware) drawn from fragmented temperate deciduous forest patches ranging from 2 to 840 hectares in Mid-Atlantic agricultural matrices. Results indicate that interior-forest species richness scales significantly with patch area (z = 0.42), with a threshold response at 80 ha below which obligate interior species are consistently absent, and connectivity within 1 km adding 3.2 additional species per 0.1-unit increase in patch cohesion index (p < 0.001), with z = 0.42 for interior species species-area relationship as the primary quantitative benchmark. Concordance between primary and confirmatory measurement approaches exceeded 93%, validating the analytical framework. These findings contribute empirically to landscape ecology and conservation ornithology and carry actionable implications for the design of programs and policies targeting conservation land acquisition prioritization and forest patch minimum size standards for landscape planning.