Goats in the Woods

This summer, Hawk Mountain Sanctuary embarked on a wooly experiment: testing the use of goats as a no-chemical alternative to invasive plant removal.

“It was certainly an experience,” laughs Hawk Mountain Director of Land and Facilities Todd Bauman, and he’s not kidding. Testing goats required herders, and mapping areas of invasion with GPS units to measure success over time. Goats also had to be supplemented with hand-pulling and other removal applications to compare the effectiveness of removal methods. 

All this fuss for one deceivingly lovely-looking groundcover: Asian stiltgrass, 
Microstegium vimineum, sometimes called Japanese packing grass, and a major threat to natural areas. Stiltgrass was introduced to the United States in 1919, likely through its use as packing material for porcelain. The bright green invasive quickly forms dense stands and in short time, chokes out native plants and tree seedlings, reduces biodiversity, and depletes the overall health of the ecosystem.  

“Even deer won’t eat it, and because the Sanctuary is bisected with a road, water runoff carries the seeds far into the forest and down to lower-level riparian areas,” explains Bauman. 

In such areas, invasive plant control becomes an even bigger challenge. “Riparian habitats are ecologically sensitive, so using a chemical spray isn’t an option there. The chemicals will spread, so you can’t limit it to the siltgrass, and that negatively affects the native species,” he says. As part of its overall management plan, the Sanctuary started in 2013 to use a target-specific herbicide on stiltgrass where it grows in low-quality habitat, such as along the roadway and around edges of parking lots. 

For the more sensitive areas, enter the goats, and with interest and support from the Pennsylvania Department of Conservation and Natural Resources and the Schuylkill County Conservancy, the Sanctuary received funding for materials as well as oversight. Other partners included local goat farmers, including a Pennsylvania Game Commission land supervisor, and local landowners interested in using goats on their own properties.


“Hawk Mountain was interested in testing goats, and forester Frank Snyder recommended a presentation I could attend, and also recommended that I talk with Tracey Coulter, agroforestry coordinator at DCNR. Tracey had more contacts, and soon we had a group interested in following this project and offering advice along the way,” Bauman says.

At the Sanctuary, three seasonal staff and one intern served as the on-site invasive plant removal team, and also were responsible for the goats. They mapped areas to pilot, erected portable electric fencing, and then during the first pilot test, carried 11 kids to the site. Here they introduced them to their new food source—lush, green invasive stiltgrass. With the kids came five adults, but it quickly became apparent that lactating adults and kids, or perhaps the relatively young age of the grass, just didn’t work. 

“The goats during our first round simply would not eat the stiltgrass,” Bauman admits, “so it was disappointing, but the team wasn’t ready to give up. The question became ‘why,’ and if other goats already proven to eat the grass could be identified, we were happy to try it again.”

And so they did. From south central Pennsylvania came four more adults who did, in fact, graze happily on the stiltgrass along with some other vegetation for the remaining two weeks of the project. The goats are now gone, but the area where they grazed will be studied for re-growth to gauge effectiveness. 

Coulter says the experiment had mixed results, but was a learning experience and one she can share with other private landowners. “We do know that animals learn to eat from one another and when introduced to an alien food source they may refuse to eat it. And while adorable, we also can now recommend that you don’t include kids with the does.  Finally, definitely do first confirm that the herd will eat the target species before moving them to your site,” Coulter says.