Eastern Black Rails (Laterallus jamaicensis jamaicensis) were surveyed during 1990, 2007, 2014 within the Chesapeake Bay region in Maryland and Virginia, USA. A network of point count locations (n = 182) was established and surveyed within tidal salt marshes. Occupancy declined during the study period from 0.84 ± 0.13 (ψ ± SE) in 1990 to 0.06 ± 0.02 in 2014. The annualized rate of decline was estimated to be 6.5%. Extinction and colonization rates between 1990 and 2014 were 0.81 ± 0.09 and 0.04 ± 0.02 respectively. Abundance declined from 1.98±0.05 Black Rails/point in 1990 to 0.26 ± 0.02 in 2014 with a 3.2% annualized rate of decline. Recruitment was 1.32 ± 1.35 between 1990 and 2007 and 0.003 ± 0.05 between 2007 and 2014. Species detection was negatively influenced by advancing season and waxing moon phase while individual detection was most strongly influenced by survey year and advancing season. Anecdotal observations of range-wide strongholds within the Chesapeake Bay suggest that sites have experienced significant declines with birds being extirpated by 2016. Declines throughout the core breeding area and within individual strongholds in the Chesapeake Bay are consistent with Black Rail declines in tidal habitats throughout the broader Northeast region.
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Vol. 44 • No. 2