*May Highlight*

The effects of habitat fragmentation on the future of wildlife in Vermont.

[developed from a presentation made to the Woodland Owner’s Association on 23 February 2006 by Kim Royar, Wildlife Biologist, Vermont Fish and Wildlife Department, as part of a series called “Conservation across the landscape” collaboratively offered by the Bonnyvale Environmental Education Center, Vermont Land Trust, and the Windham Regional Commission ]

Vermont is home to a wide variety of life. Roughly 250 different species of birds, 50 kinds of mammals, 75 species of fish, and 20-30 species of reptiles and amphibians can be found in the Green Mountain state. This level of diversity is dwarfed, though, when compared to the number of invertebrate insects, worms, and other animals without backbones in Vermont, who number in the neighborhood of 20,000 different species. Through the recent development of Vermont’s State Wildlife Action Plan, 143 vertebrates, 192 invertebrates, and 577 plants were identified as being Species of Greatest Conservation Need. Many people know about the common plants and wildlife in Vermont, but for a listing of those considered rare, see the state’s Nongame and Natural Heritage program.

Wildlife habitat in Vermont that supports the diversity of life is threatened by habitat conversion and fragmentation, roads and trails, pollution and sedimentation, invasive species, and climate change. Habitat conversion is easy to see and understand- where there once was woods or meadow, there now sit houses, parking lots, or highways. But fragmentation is harder to see - larger parts of natural habitat carved up into smaller pieces, divided by more roads, houses and other forms of development. Southern Vermont is still heavily forested, so is it really all that fragmented? Change is coming to Vermont, as evidenced by the following statistics:

Indeed, 40% of the private property owners in Vermont fall into this 1-9-acre category. Many more people are collectively making decisions about the future of all wildlife habitat. And since roughly 87% of all land in Vermont is in private ownership, the trend of increased parcelization, and dividing habitat up into smaller and smaller pieces can continue. Population growth statistics suggest that much of this growth is occurring in rural areas (defined as fewer than 2,500 people). In 1960 Vermont’s rural population was roughly 240,000. By 1990, it was 382,000.

As fragmentation occurs, natural forested habitat is divided into smaller and smaller pieces. “Core forest” is that which is back from development by roughly 300 feet. These areas are ones that are relatively free of the effects of increased human population. As fragmentation proceeds, our core forest areas shrink in both size and number.

You might be convinced by these statistics that fragmentation of Vermont habitat is occurring, but why does it matter? How does fragmentation affect Vermont wildlife? Fragmentation changes the species composition of wildlife by favoring “generalists” like raccoons, skunks, and cowbirds at the expense of more sensitive “specialists” like neo-tropical migrating songbirds, wide-ranging mammals, amphibians and reptiles, and bats. Generalists actually like more backyards, compost piles, and gardens, but other wildlife are far more sensitive to change and humans. Fragmentation not only alters species composition towards the generalists, but it also literally decreases the amount of habitat we have- it is estimated that Vermont loses 6,500 acres of habitat annually to development.

Absolute habitat loss and fragmentation also restricts wildlife movement. In the last quarter of the 20 th century, Vermont expanded its road system by 26 miles per year, and the number of vehicle miles driven by Vermont residents is growing at 7 times the population growth. During the last decade, Vermont human population grew by 8.2%, while the number of non-commercial vehicles increased by 24%. All these increased roads, vehicles, and traffic results in direct wildlife mortality - for example, more than 2,500 deer and moose die annually on Vermont roads, and who knows how many snakes, turtles and amphibians are killed this way? Besides resulting in direct mortality, roads can disrupt natural wildlife movement patterns, resulting in isolated populations. If wildlife can’t move from habitat to habitat, they breed with one another and genetic variability is reduced.

Fragmentation and land use conversion promotes the introduction of invasive exotic species that out-compete our own native plants and animals. Vermont has developed an excellent invasive exotic fact sheet that explains what these species are, how they spread, and the threats behind them. Imagine a situation, where Norway Maple could outcompete Vermont’s own sugar maples.

Fragmentation and land use change further impact wildlife habitat by altering the way Vermonters view and use land. In 1940, 62% of the state was in farmland, but since 1960, the trend has been shifting more towards a commercially based economy and a 40% loss in farms. Along with the shift in land use and economy comes a change in traditional attitudes- going from agrarian, natural-resource-based land-sharing ways of thinking and making a living, to thinking about land as tourism, recreation, and a sporting playground (Andrew Nemethy, Rutland Herald). Vermont ranks highest in the nation for residents participating in wildlife-based activities, including viewing, hunting, fishing, and photography. In 1996, residents and non-residents spent $341 million in Vermont on wildlife-related activities. 240,000 Vermonters engage in wildlife activities, which amounts to 11% more than ski in Vermont. Over time, and due to less involvement in land as part of the economy, people become less connected to the land. As land is fragmented and cut into smaller parcels, access for recreation becomes lost or more restricted, which can result in a decline in participation. As land is divided into smaller parcels, it becomes more difficult to manage or take care of, and shifts away from a so-called working landscape of forests and farms. The jigsaw puzzle of landscapes and wildlife habitat grows increasingly complicated, with more people making decisions about the future of the land. Add to that complex and shifting situation the fact that people’s attitudes towards wildlife change - people might not like wildlife as much when they have bear in their garbage cans or deer eating their crops or tree seedlings.

So- there can be little doubt that fragmentation and habitat loss (and their effects) are the twin threats to wildlife in Vermont, but what can be done? As habitat continues to be lost or fragmented, and population grows, it could be said that Vermont is at a crossroads for wildlife. Though there have been significant changes to Vermont’s landscape in the past (e.g., the conversion to open farm land in the 1800s), this form of conversion is now permanent. Roughly 87% of Vermont is privately owned, so the future of habitat, and the degree of conversion and fragmentation really depends on private woodland owners and the decisions they make about their land. One important thing that woodland owners can do is remember that wildlife habitat does not start or stop at individual property boundaries. For example, bobcats have home ranges of 12 – 36 square miles. Home range of white-tailed deer can be well over 1,000 acres. Annual home ranges of fisher can be as much as 7.4 square miles. Adult female bears range from 6 – 19 square miles, and males can wander over much larger territories. Even small animals like the Cerulean warbler require extensive mature forest habitats of 600 acres or more. So when considering the future of land, think about identifying large contiguous forest blocks, and looking for ways to conserve them. Identify and protect critical habitats and rare natural communities like vernal pools. Identify and protect movement corridors between habitats, as well as riparian corridors which can also be used for movement through the landscape, as well as a source of important aquatic habitat.

It is not enough to simply find these important habitat features or consider them. With so many families, individuals, and organizations that own land, there is a significant role for working together and partnering at scales larger than individual properties to ensure their protection in the face of fragmentation. In fact, this is one of the reasons ACORN was organized: to help people “see” their land in the larger landscape or habitat context (if you haven’t yet, check out the MapServer opportunity in ACORN), and find sources of information that pertain to their local area, to help them make informed decisions about the future. There is, for example, an obvious role for the use of easements and land protection, to assure that large blocks of habitat are not developed in the future. ACORN’s section on land protection provides useful links and information on easements, so that woodland owners can protect land from future development, yet still own it and enjoy it. By communicating with one another about future possibilities or threats, woodland owners and citizens can collaborate on solutions to the habitat fragmentation issue that they might not otherwise be able to do alone.

Aldo Leopold, the famous wildlife biologist and forester could see the vital role of people in the protection of habitat decades ago, when he wrote: “[T]he real substance of conservation lies not in the physical projects of the government, but in the mental processes of citizens”. The threats of fragmentation and habitat loss are far greater today, and the actions of citizens have never been as important.