Goats Influence Avian Research in Frick Park

Exciting things are happening at Frick Park’s Clayton Hill! 

In August, the Pittsburgh Parks Conservancy introduced you to Team Hobo, the herd of 11 goats (and a guard donkey) from Allegheny Goatscape as it initially arrived at Clayton Hill in Frick Park to begin its assignment of removing invasive bush honeysuckle from the area. The Pittsburgh Parks Conservancy (PPC) and Allegheny Goatscape, along with partners in the Allegheny Bird Conservation Alliance (ABCA) – including the Western Pennsylvania Conservancy and the Carnegie Museum of Natural History – are working to restore native forest habitat to improve ecosystem health and benefit birds. The basic restoration strategy at Clayton Hill is to remove destructive invasive plant species from the forest (using browsing by goats and manual removal), replace the invasives with appropriate native plants, and monitor the effects on both breeding birds and migrants.

Recently, Team Hobo arrived at Clayton Hill once again to start its next assignment of removing invasive species from the 155-acre woodland of the park.

However, this next assignment is not going to be a walk in the park for our four-legged friends.

"The goats had the easy job before because they fed in the same area that they have for the past couple of years, and it is a site that the Department of Public Works park crews had helped prepare the previous winter by mowing down bush honeysuckle that was 10-feet tall and so thick that a person could not walk through the site," Phil Gruszka, Director of Horticulture and Forestry at the Pittsburgh Parks Conservancy.

“Now the team is going to feed on sites that were not prepared for them. The bush honeysuckle was not cut down, so the goats have a heavy lift when they go to this new site. They are going to have to work for their dinner, and oh, breakfast and lunch too," Phil continued.

So, why is this project taking place? 

Recent conservation research shows that across North America, bird populations have declined by 30% since 1970, and we have lost nearly 3 billion birds (www.3billionbirds.org). This includes 2.5 billion migratory birds like warblers, vireos, and orioles and 170 million eastern forest breeding birds like the Wood Thrush and Scarlet Tanager. Habitat loss is the number one driver of these declines, followed by habitat degradation – including forests altered by invasive plants or fragmented by roads and other development.

In 2015, Pittsburgh was designated an Urban Bird Treaty City. The ongoing work in Clayton Hill addresses the goals of the Urban Bird Treaty Program, including protecting, restoring, and enhancing urban/suburban habitats for birds, reducing urban/suburban hazards to birds, and educating and engaging the public about the role of birds in our everyday lives and the health of our ecosystems. The Parks Conservancy, Carnegie Museum of Natural History, and the Western Pennsylvania Conservancy, all members of the Allegheny Bird Conservation Alliance, are partners on the bird surveying and monitoring components of this project.

Even within the urban landscape of the region, Allegheny County provides habitats for birds. The natural areas and green spaces provide vital stopover sites – places for birds to rest and refuel – for the millions of birds migrating through the state each spring and fall. Neotropical migrant songbirds, which spend most of their year in Central or South America but take advantage of spring and summer resources for nesting in North America, need native habitats like the Red-Oak Mixed Hardwood Forest and Dry Oak-Mixed Hardwood Forest that the team is currently restoring in Clayton Hill.

Now, work continues the implementation of the integrated vegetation management and native plant restoration of the woodland area; this will improve the ecological health of the site. Many migrants, like myriad warbler species including American Redstart, Connecticut Warbler, and Mourning Warbler, fuel their migration with insects – particularly moth caterpillars. These insects are dependent on native vegetation. For example, moth caterpillars require specific host plants to survive, and the oak genus Quercus alone supports more than 500 species of moths! Similarly, many migrant songbirds such as Wood Thrush and White-throated Sparrow feast on late summer and fall seeds and fruits, and berries from native trees and shrubs, like spicebush, viburnums, or dogwoods, hold higher levels of nutritious fats than non-native invasive shrubs like multiflora rose, honeysuckles, or autumn olive –as much as 30-50% for natives versus just three to four percent for the invasives.

This is a critical project that combines professionals from diverse backgrounds. University of Pittsburgh professors will evaluate plant community health. Local avian researchers will monitor bird populations to establish a baseline survey of avian species and assess population changes over time. Pittsburgh’s community of amateur and professional birders will continue to add data to the eBird hotspot established for this project but more help is needed to foster enough data to make an impact on this project.

The results from the data will be a record that reflects changes in species diversity and abundance at the site. Over time, these results will provide a further understanding to share with other professionals in the industry on the impact of invasive removal, particularly bush honeysuckle, on the health and nesting viability of urban bird populations.

Throughout this fall migration season, ABCA partners and citizen-scientist volunteers have been monitoring the birds using Clayton Hill within four different restoration areas. With different habitat restoration activities happening within each area, we will be able to compare how birds respond to habitat improvements. Here are the bird monitoring results so far:

Frick Park - Clayton North (Monitoring) - 90 species, 107 checklists
Frick Park - Clayton East (Monitoring) - 82 species, 77 checklists 
Frick Park - Nature Trail East (Monitoring) - 28 species, 15 checklists 
Frick Park - South Clayton West (Monitoring) – 64 species, 57 checklists

This project promises to yield data that will demonstrate the impact of improved habitat on bird populations in the park. Stay tuned for more project updates along the way! 

Are you ready to help us with this vital citizen's science project? Learn more! 

Special thanks to David Yeany of the Western Pennsylvania Conservancy for contributing to this article and to the National Fish and Wildlife Foundation (NFWF) for awarding the Parks Conservancy the Five Star and Urban Waters Restoration Program grant and making this project possible!