Richmond Battlefield Birds, 2019: A Healthy Forest Community, Few Grassland Specialists

Richmond National Battlefield Park has used prescribed fire since 2005 to maintain native warm-season grass meadows as bird habitat, yet in 2019 volunteers recorded only two grasshopper sparrows there. The forests tell a better story: ovenbirds and wood thrushes, two species that depend on larger intact forest, were relatively abundant, and the park's forest bird community scored as moderately to highly healthy. That is the picture from a National Park Service brief on the park's 2019 breeding bird monitoring.

Prescribed fire is the preferred management tool for maintaining native warm-season grass meadows. These native grasslands provide critical habitats for many increasingly rare birds. NPS / J. Shafer.

How the monitoring works

For ten years, the brief says, scientists of the Park Service's Mid-Atlantic Network have worked with skilled local volunteers to monitor bird populations in national parks across the mid-Atlantic region. The information improves understanding of the relationships between breeding birds, available habitats and park resource management, with the goal of developing the best available science so parks can better understand and protect their resources.

In the summer of 2019, volunteers conducted 86 surveys at 34 sites across the park. During a survey they documented every bird heard or seen over a ten-minute period, and sites in both forest and grassland habitat were visited multiple times during the breeding season. The brief puts the park's native warm-season grass meadows at 96 acres.

Species of regional concern

Partners in Flight is a network of organizations involved in bird conservation in the Western Hemisphere. It has identified a number of bird species that are declining and facing increasing threats across the mid-Atlantic region, and 14 of these species of regional concern were observed in the park in 2019. The ten most observed:

Grassland sites

The most abundant bird in grassland sites was the indigo bunting. European starlings, a non-native bird, were also abundant, mainly because of a single large flock. Most birds seen in grassland sites were habitat generalists, and native grassland specialists were uncommon: the grasshopper sparrow, a species of conservation concern, was present but in very low abundance. The brief says continued and improved management of the warm-season grass meadows should support a future increase in grassland-dependent species like it.

Figure 1. Ten most abundant birds in grassland sites in 2019 (average number observed per site). Chart from the National Park Service's brief.

Forest sites

The European starling was again the most abundant bird in forested sites, again because of a large flock. Ovenbirds and wood thrushes, both species of regional conservation concern, were also relatively abundant. These two depend on larger intact forest ecosystems, and with increasing urbanization around the park, the brief says, their relatively high abundance shows the importance of park forests to local bird populations.

Figure 2. Ten most abundant birds in forested sites in 2019 (average number observed per site). Chart from the National Park Service's brief.

Forest bird community index

Scientists can study the abundance of all the bird species in an area to judge the overall health of the bird community. The forest bird community index described by O'Connell and colleagues in 2000 puts the park's forest bird community at moderately to highly healthy, meaning medium to high integrity. With increased urbanization around the park, it may be difficult for the park to support this full forest bird community indefinitely, and the brief suggests that conserving forests on surrounding private lands may be important for its long-term persistence.

Figure 3. Forest bird community index score (2009-2019). Chart from the National Park Service's brief.

Sources

• National Park Service, Mid-Atlantic Network, Breeding bird monitoring at Richmond National Battlefield Park: 2019 status and trends; the brief's volunteer count is left out because the page gives two different numbers, and its Flickr photo of an indigo bunting is not reproduced; rewritten in hubnx's own words.