POISON IVY FOR BREAKFAST, SCRUB OAK FOR DINNER
SHEEP CURTAILING INVASIVE PLANT SPECIES
BY PETER B. BRACE INDEPENDENT WRITER
There is a delectable combination of island vegetation on the menu for the 29 Romney and Cotswold sheep that are spending the summer at Squam Farm.

ROB BENCHLEY/The Independent file

The Nantucket Conservation Foundation, now in its third summer of research, is sharing preliminary results of a study as to what invasive species of plants - plants that dominate and edge out less competitive and aggressive species of vegetation - sheep might eat on Nantucket.

Hoping to have a completed report by next spring, study leader Karen Beattie should be making recommendations that will work sheep into a vegetation control program that already includes controlled burns and the mowing of selected parcels on the foundation's holdings of 8,800-plus acres around the island. The sheep, it is theorized, could play a crucial and unique role in this effort that fire and mowing do not.

"A lot of the preliminary things we're observing anecdotally are very encouraging," said Beattie. "They're eating invasives, and another thing that sheep do that burning and mowing don't do is their hoof action breaks up the ground and the roots of the shrubs, creating a place for seeds to germinate."

Before prescribed burns and motorized mowers came into being, Nantucket's founders were sheep farmers who grazed sheep all over Nantucket on pastureland they shared, the sheep commons.

Originally an island of rolling grasslands with pocket forests here and there, Nantucket's landscape was shorn to grass and low shrubs by the grazing sheep. Invasive species that now blanket much of the island's conservation land, including Japanese pitch pine, scrub oak, poison ivy and Japanese huckleberry, could not get a foothold on the island because of the sheep's insatiable appetite.

Beattie, along with NCF's Science and Stewardship Department, including Shepherdess Nicole DuPont and Properties Maintainer Chris Iller, both working behind the scenes on this study, are quickly learning about present-day sheep's dietary preferences on Nantucket.

"They do eat scrub oak earlier in the season when the leaves are young in the spring," said Beattie. "They do eat grape, they like to eat Japanese honeysuckle and we've seen them eat poison ivy. Some of them, do not like bayberry or sweet fern, the aromatics."

Spending their downtime in a large paddock near the Squam Farm barn, the sheep are rotated between different fenced-in plots in fields and meadows on the property to see what species they'll eat and what grows up in its place. After the sheep eat the vegetation down to the nubs, they're moved out to another plot or to the main paddock so the plants can grow back. The sheep are then rotated back to plots where vegetation has grown in again. All the while, Beattie and her charges monitor what is eaten and what grows in.

"I think we're currently on a third round of grazing for the season. We put them out for as long as possible so that they eat as long as they can."

When this research began in 2005, NCF and project initiator Brook Brewer chose Squam Farm because it did not have that many rare and endangered species that the sheep might eat. But the first summer's research, which began with 31 Cotswold sheep on loan from the New England Heritage Breeds Conservancy, one of the breeds originally raised by Nantucket settlers, got hobbled from the get-go as many of the sheep gave birth to lambs. Instead of research, the crew had nursery duties. A two-month drought that summer did not help.

At the end of that season, Beattie and Brewer sent back the adult sheep but kept the lambs. What they learned the next season was that the lambs ate everything their parents would not, including poison ivy, grape vines, hazelnut and scrub oak shoots.

This year's group of sheep includes 11 lambs born this spring, seven lambs from 2005, a ram that the Foundation purchased, one donated sheep and about nine sheep from the Massachusetts Audubon Society.

With preliminary observations looking positive, Beattie said she hopes to provide the Nantucket Conservation Foundation with solid evidence that sheep can go hoof to hoof with mowers and fire in keeping invasive plant species at bay.

"By next spring, we're going to analyze the data we have from the last three years and say what sort of role sheep grazing can play in grassland and

heathland conservation efforts," she said. I