Streamside Bird Monitoring in Delaware Water Gap National Recreation Area

Veery (Catharus fuscescens) with caterpillar in bill. Veeries are one of the most abundant bird species at Delaware Water Gap National Recreation Area point count stations.
Photo © Bill Thompson.

A new report from the Eastern Rivers and Mountains Network summarizes the first 12 years (2007 to 2019) of monitoring the streamside bird community at Delaware Water Gap National Recreation Area. During that time period 13 observers conducted 3,970 point count surveys detecting 33,263 individual birds at 216 point count stations within the park.

Delaware Water Gap National Recreation Area contains a rich and diverse streamside bird community with a total of 112 species detected; 87 of which were target species and presumed to be breeding in the park during summer months. The majority were forest-associated species including forest-interior species whose life-histories depend on large tracts of mature, unfragmented, deciduous forest and forest-generalist species. However, several abundant species were associated with early-successional forests, shrubby fields, and suburban landscapes reflecting the mixed vegetation structure at the park including at the point count stations.

Twenty-three species overall and three of the five most abundant species were of conservation importance in the Appalachian Mountains bird conservation region highlighting the significance of Delaware Water Gap National Recreation Area and the surrounding landscape to avian conservation (Figure 1).

It is striking, and one of the more significant findings of the monitoring program to date, that out of 87 species in the target population, 77 species (89%) were stable or increasing and only 10 species (11%) declined during the period of monitoring.

Figure 1. Twenty most abundant streamside bird species at Delaware Water Gap National Recreation Area point count stations from 2007–2019. Bars represent the unadjusted mean birds per point (+1SD) across all years of monitoring. *Species of regional conservation importance.

Several of the species showing stable or increasing populations trends at Delaware Water Gap National Recreation Area point count stations were species of regional conservation importance due to decades of population declines throughout the Appalachians (e.g., Wood Thrush) or were priority species for regional conservation (e.g., Scarlet Tanager, Wood Thrush, Eastern Wood-Pewee, and Hooded Warbler). An encouraging sign in the face of recent overwhelming evidence of dramatic declines in bird populations.

This report provides the first information regarding long-term population trends of breeding birds in Delaware Water Gap National Recreation Area. Continued monitoring will provide new insights and future analyses will explore specific factors linked to population trends. As anthropogenic land use and climate change continue to reshape the Appalachian landscape, park managers will need this information to best allocate effort that aligns with regional conservation planning and other park priorities.


Report Citation:

Marshall, M. R. 2021. Streamside bird monitoring in the Eastern Rivers and Mountains Network: Delaware Water Gap National Recreation Area 2007–2019. Natural Resource Report NPS/ERMN/NRR—2021/2326. National Park Service, Fort Collins, Colorado. https://doi.org/10.36967/nrr-2288147.

For more information, contact the Eastern Rivers and Mountains Network Program Manager, Matt Marshall.