In 1988 I wrote a commentary for the Gazette in which I described the extinct heath hen as an umbrella species. Protecting and managing habitat for an umbrella species results in the conservation of numerous other imperiled or declining species. At the time, I believed that the heath hen was a grassland-dependent animal and most modern accounts supported a strong grassland association for this bird.
What have practicing conservationists learned since 1988? An examination of written accounts, including many first person observations, published between 1800 and 2000 indicates that woodland habitats, albeit frequently burned but wooded habitat, was preferred by heath hens.
Alfred O. Gross, who conducted his thesis at Bowdoin College on the pinnated grouse in the 1920s while the extinction that was about to be completed in 1932 was well underway, wrote the following account: “When you examine the miles of scrub oaks that occupy the center of the island you readily note the very uneven surface caused by the interspersal of the taller black and white oaks which at present range from four to ten feet in height. The scrub oak growth which occupies the bulk of the area is less than three feet in height . . . In certain places there were dense growths of aspen, black alders and gray birches with here and there a few scraggly specimens of scrub pine. More rarely a Crataegus (hawthorn) and a wild-cherry tree were seen. There were numerous patches of sumac and on the plains bordering the south shore impenetrable thickets of bayberry more or less overgrown with tangles of vines. All through the scrub oaks there were masses of sweet fern and blueberries and huckleberries abounded everywhere.”
To check whether this description was perhaps anomalous, I consulted literature from other places where heath hen populations once existed. Every one of them, including accounts from Long Island, New York, the New Jersey pine barrens, the Poconos in Pennsylvania, the Connecticut Valley in Massachusetts and Connecticut all confirmed a decidedly forested habitat was favored by this animal.
We apply other tools to determine the ecological history of a place. The microscopic examination of pollen and charcoal, as they are preserved in pond sediments, is a powerful tool for reconstructing vegetation histories. Many samples from multiple ponds on Martha’s Vineyard have been processed, and if the grassland habitats such as those found at Katama Plains and Wasque were here historically, they would be revealed by the presence of large amounts of grass pollen. There is no evidence that large grasslands such as these ever existed prior to European invasion and settlement of the Island. This leads to a fundamentally important question: are these large grasslands that once supported short eared owls and regal fritillary butterflies even native to this landscape? It may be time to listen to the preponderance of evidence and debunk the great grassland myth.
Why is this important? Modern habitat management is an adaptive, cyclical endeavor. A proponent describes in considerable detail the habitat type and extent to be managed or restored for specific plant and animal species. In step two, management actions are conducted, followed by step three where measurements are collected to determine whether one is achieving the stated goals. This feedback loop results in the alteration of the initial goal or alteration of the management techniques in a constantly self-informing cycle. If the original supposition is false, scarce conservation dollars are at risk of being wasted on projects that are not viable. Research on the habitat needs of prairie chickens concludes that a functioning population requires an area of 9.7 square miles. It would be dangerously damaging to convert that much shrubland and woodland to grass-dominated habitat.
Protect, manage and restore the remaining grasslands we have. They are important to our biodiversity and to our cultural history. The equally important and fascinating fire-dependent shrublands and ancient woodlands in the Manuel Correllus State Forest and elsewhere deserve increased attention and financial resources to perpetuate them for future generations to enjoy. But be very wary of any proposal that would result in converting these habitats into something they have never been.
The very new genetic modification technology emerging today will affect every aspect of our futures and can and should be explored very cautiously. The problems associated with deer hyper-abundance are multi-dimensional and deeper than increased disease incidents in humans and the disease carrying capacities of small mammals. Deer overabundance also results in the deterioration of habitat health, the loss of plant populations that are subjected to over-browsing and even the loss of bird populations deprived of their forest understory cover. These corollary issues will not disappear even if modifying the Island’s resident mice were to be successful.
Tim Simmons recently retired from his position as restoration ecologist at the Massachusetts Natural Heritage & Endangered Species Program but remains a practicing conservation ecologist.
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