Old News Archive

IFW Outdoor Report -- Maine Is Full Of Special Habitats

March 27, 2007 - TRC

Special Habitats Throughout the State Of Maine

Interspersed throughout the State of Maine, there are areas that the Department of Inland Fisheries and Wildlife has identified as “special habitats” IFW is monitoring and managing these special habitats for specific species or species groups. These habitats range from pitch pine barrens to New England Cottontail habitat to seabird nesting islands. Each of these habitats supports a unique suite of species or provides special features that meet the needs of species in decline. This is by no means all of the habitats of conservation concern that Department staff are addressing, but these are areas that do require a more monitoring. Part of the funding for these efforts comes from one or more of the following sources: Maine’s Conservation Plate, Chickadee Checkoff, or Outdoor Heritage Fund; the Maine Chapter of the Nature Conservancy, as well as the U.S. Fish and Wildlife Service, Natural Resource Conservation Service, and Environmental Protection Agency.

--Richard L. Dressler, Supervisor, Wildlife Resource Assessment Section, Department of Inland Fisheries and Wildlife

Pitch Pine Woodlands and Barrens
Pitch Pine woodlands and barrens are lightly forested upland areas with dry, acidic, often sandy soils. Pitch pine, red pine, scrub oak, blueberry, huckleberry, and/or bluestem grasses are commonly among the sparse vegetation of this unique natural community. It’s thought that over half of the state’s original pine barren acreage has been lost to residential development, agriculture, and gravel mining. Many dry woodlands and barrens also require periodic fire to prevent succession to a more common, closed canopy white pine-oak system, a natural disturbance that is now short-circuited by habitat fragmentation and fire suppression.

Once viewed as unproductive “wastelands”, Maine’s few remaining pine woodlands and barrens are now recognized as areas of exceptional wildlife value, providing habitat for a variety of highly specialized plants and animals.

Several rare and endangered species are restricted to the state’s few remaining intact barren communities, mainly in Kennebunk, Wells, Waterboro, Shapleigh, Hollis, and Fryeburg. The barrens are especially rich in rare Lepidoptera (butterflies and moths), hosting species that feed on the specialized barrens vegetation, such as Edward’s Hairstreak (Endangered), Sleepy Duskywing (Proposed Threatened), Cobweb Skipper (Special Concern), and Barrens Buck Moth (Special Concern). Other rare species associated with Maine’s barrens include Black Racers (Endangered), Grasshopper Sparrows (Endangered), Upland Sandpipers (Threatened), Short-eared Owls (Proposed Threatened), and Northern Blazing Star (a Threatened plant). To learn more about two barrens of statewide ecological significance visit “Focus Area Descriptions” on the Maine Natural Areas Program website at (http://www.mainenaturalareas.org/docs/program_activities/land_trust_descriptions.php - York_County), and select “Kennebunk Plains and Wells Barrens” or “Waterboro and Shapleigh Barrens”.

--Phillip deMaynadier, Wildlife Biologist, Department of Inland Fisheries and Wildlife

Vernal Pools
Vernal pools are small, forested wetlands that frequently fill with water from early spring snowmelt and rains and then dry partly or completely by mid to late summer. Many of Maine’s amphibians use vernal pools as breeding or foraging habitat. Some, like spotted salamanders, blue spotted salamanders, and wood frogs, breed more successfully in these fishless habitats than in any other wetland type.

Additionally, vernal pools provide habitat for a variety of small mammals, wading birds, waterfowl, aquatic invertebrates, and several state-listed animal species including Blanding’s turtles (Endangered), spotted turtles (Threatened), wood turtles (Special Concern), four-toed salamanders (Special Concern), ribbon snakes (Special Concern) and ringed boghaunter dragonflies (Endangered).

We still have more to learn about why some vernal pools receive greater wildlife use than others. To this end, grants from the Outdoor Heritage Fund and the U.S. Environmental Protection Agency helped support a recently completed University of Maine study by Dr. Robert Baldwin and Dr. Aram Calhoun, to research the wildlife use and characteristics of vernal pools in four southern townships – Falmouth, Biddeford, Kennebunkport, and North Berwick. Rob and Aram’s results suggest that wood frogs and other pool-breeding amphibians range widely in the forested landscape following breeding and that surrounding upland forests and forested swamps provide important habitat outside of the brief pool-breeding season. Rob also developed a landscape model that highlights the vulnerability of vernal pools to habitat loss and fragmentation from insufficient conservation lands and wetland regulations in southern Maine.

IFW is currently cooperating with the Department’s of Environmental Protection and Conservation, Maine Audubon Society, and the University of Maine to identify potential strategies for protecting the unique values provided by smaller wetlands that “fall through the cracks” of current wetland regulations. Workshops on vernal pools continue to

be held throughout the state for landowners and land managers, and several new publications designed to offer voluntary techniques for protecting vernal pools and their wildlife are now available. A vernal pool fact sheet, describing threats and management considerations, is available upon request from MDIFW for use by landowners, municipalities, land trusts, and other cooperators. The Maine Citizen’s Guide to Locating and Documenting Vernal Pools provides a comprehensive introduction to recognizing and monitoring vernal pools, including color photographs of the indicator species. Also recently available to the public are two complementary guidebooks for protecting vernal pool habitat during timber management (Forestry Habitat Management Guidelines for Vernal Pool Wildlife) and development (Conserving Pool-breeding Amphibians in Residential and Commercial Developments in the Northeastern United States).

Together, these publications provide recommendations designed to help maintain functioning vernal pool landscapes throughout Maine. All of the guides can be obtained by contacting Becca Wilson at Maine Audubon Society (207-781-6180 ext. 222; bwilson@maineaudubon.org).

Finally, the Dept’s of Inland Fisheries and Wildlife and Environmental Protection recently developed a definition of Significant Vernal Pools, a new Significant Wildlife Habitat under the state’s Natural Resource Protection Act, approved by the state legislature in 2006. Criteria for designating “significant” vernal pools include a) the presence of a state Endangered or Threatened species, or b) evidence of exceptional breeding abundance by amphibian indicator species. Designating a subset of vernal pools as “significant” will help state agencies provide regulatory guidance on development activities within a critical upland buffer zone surrounding one of the state’s highest value wildlife habitats.

--Phillip deMaynadier, Wildlife Biologist, Department of Inland Fisheries and Wildlife

Rabbit Habitat – More Than Just for Rabbits

When people think of rabbits, they do not usually associate them with critically important habitats or endangered or threatened species. Rabbits are supposed to be numerous and occur just about everywhere. Right? Below, we discuss the links between rabbit habitat, endangered and threatened animals, rabbit predators, and people.

Maine has two species of rabbits: one of which is commonly seen, and another that is becoming increasingly rare. Our most common rabbit, technically, isn’t a rabbit at all, although it often has been referred to as one. It is the snowshoe hare, and is found in most areas of the state. Hares are distinguished from rabbits by their larger size, longer ears, longer legs, and skull morphology. Hares are born fully furred with open eyes, while rabbits are born in a much more vulnerable state without fur and their eyes closed. Snowshoe hare are important because just about every predator in the state, including man, likes to eat them. Without snowshoe hare, Maine’s bobcat, lynx, fisher, marten, coyote, fox, and great horned owl populations would be considerably reduced. Although snowshoe hare make up a substantial portion of the diet of many of these species, the Canada lynx is the predator that is most dependent on them. Canada lynx are a federally threatened species, and the recent increase in their population in Maine has been attributed the abundance of snowshoe hare that currently exists in the state. Considerable effort has gone into studying the relationships between snowshoe hare, lynx, and their habitats. Basically, it comes down to snowshoe hare. If the habitat can support high densities of snowshoe hare, lynx will likely do well in that habitat.

Maine’s other rabbit is the New England cottontail. New England cottontails are Maine’s only true rabbit and occur in the southernmost reaches of the state. Unfortunately, suitable habitat for New England cottontail has decreased by more than 70% since 1970 and is very fragmented (occurs in small patches less than 5 acres in size). This loss of habitat, and the accompanying decline in the New England cottontail population, has led to the Department proposing cottontails for state endangered species status. This is quite a change for a species that in the past was much more abundant, frequently hunted by humans, and a major prey item for bobcat.

In general, the type of habitat needed by snowshoe hare and New England cottontail is early successional habitat. Early successional habitat can be regenerating forests, old fields, shrublands, or grasslands. The term “early successional” refers to the group of plants that first grow in an area after a major disturbance, such as a fire, windstorm, or forest cutting. Many species of wildlife such as moose, deer, woodcock, ruffed grouse, songbirds, and black racer snakes use early successional habitat to find food and cover. Unfortunately, it is a habitat type that has become increasingly scarce in the Northeast.

The principal habitat feature needed by both snowshoe hare and New England cottontail is cover from predators. Although cover is important for both species, the type of cover preferred by each species is different. Cover for snowshoe hare becomes suitable when vegetation is so thick that it obstructs 40% of what a person, or predator, can see. Cover becomes optimal when it obstructs 90% of vision. In terms of small trees or bushes, at least 20,000 stems per acre are needed to provide good cover for snowshoe hare, and the best cover is produced by coniferous trees, such as balsam fir. In the winter, coniferous trees provide about 3 times the amount of cover as deciduous trees. A regenerating coniferous forest usually provides adequate cover for snowshoe hare after it is 10 years old, and may continue to provide high quality cover for another 20 years in Maine.

Although coniferous trees proved the best cover for snowshoe hare, they are not the preferred cover type for New England cottontail. New England cottontails prefer old fields with lots of deciduous shrubs and green plants (forbs). These shrubs and plants not only provide cover for New England cottontail but also an abundant food source. Although a young coniferous forest could provide New England cottontails with cover, it usually does not have the quality and quantity of food needed by these rabbits. Snowshoe hare, on the other hand, appear to do fine in dense conifers with occasional openings where edible plants can be found.

Maintaining sufficient habitat for New England cottontail in the future will be challenging. In the past, suitable habitat for New England cottontail in Maine was created when farms were abandoned, forests were cleared, or when storms blew down trees. Today, there are fewer farms in Maine than there were 50 years ago, and any land that is

abandoned, usually reverts to mature forests or is developed. The Department will be working with environmental organizations, land trusts, and landowners to try to set aside land for New England cottontail throughout its former range in Maine and populate these areas with cottontails. Our hope is to set aside enough habitat for New England cottontail to allow the population in Maine to become self-sufficient, stabilize, and eventually increase in size.

Maintaining sufficient habitat for snowshoe hare may be easier in northern Maine where large-scale forestry operations are ongoing, than in southern Maine where there is more residential development. Currently, snowshoe hare habitat in northern Maine is near optimal levels as the result of clearcutting and forest salvage operations that occurred in the late-1970s to mid-1980s. The question is whether current forestry practices, such as shelterwood cuts and other forms of partial harvesting, can provide the dense understory needed by snowshoe hare. We know from recent studies that pre-commercial thinning of forests reduces a stand’s suitability for snowshoe hare. Currently, our Department is cooperating with researchers at the University of Maine to investigate the effects of

various forest harvesting techniques on snowshoe hare and lynx. We hope to offer habitat management recommendations for maintaining snowshoe hare and lynx habitat to landowners in the near future. Hopefully, with the cooperation of landowners, we will be able to ensure the well being of snowshoe hare and all of the predators that depend on this species for their survival.

--Wally Jakubas, Wildlife Biologist, Department of Inland Fisheries and Wildlife

Important Bird Areas
Identifying areas of importance to birds stems from an international project begun in the 1990s by BirdLife International in Great Britain. In 2001, Maine Audubon, with the assistance of staff from the Maine Department of Inland Fisheries and Wildlife (IFW), set out to identify the most important areas for bird conservation in Maine. This project follows others throughout the U.S. that set forth similar objectives, each with a slightly different approach. In Maine, we created a steering committee that we informed of the project and its status, and more importantly, a technical committee to advise us on establishing numeric criteria for assessing importance of areas.

An Important Bird Area (IBA) is a location that provides important habitat for one or more species of breeding, wintering or migrating birds. IBAs generally support birds of conservation concern, including Threatened and Endangered Species, large concentrations of birds, or birds associated with unique or exceptional habitats.

Furthermore, an IBA may be an area, which has historically been the location of a significant amount of avian research. In Maine, we typically identified “sites” which met certain numeric thresholds for abundance and diversity then assembled groups of these “sites” into “areas” (i.e., IBAs) based on their proximity to one another or thematically, typically based on the ecosystem within which they occur.

At the outset of the project, we thought we could simply identify 100 places in Maine that are important for birds. However, the magnitude and complexity of the project have been at times overwhelming. Analyses to date have identified over two dozen areas of high importance to bird conservation. We feel we have reached a “critical mass” and anticipate releasing a report, featuring site descriptions for each site and IBA. Each description will include, a discussion of bird populations there, as well as conservation issues affecting the site.

--Thomas P. Hodgman, Wildlife Biologist, Maine Department of Inland Fisheries and Wildlife

Seabird Nesting Islands
There are 3,000 to 4,000 islands and exposed ledges off the Maine coast. Prior to the last ice age, these exposed features were actually the tops of ancient mountains. Many islands consist only of bare rock and are completely devoid of soil and vegetation. Vegetated islands range from small grassy islands to large islands dominated by spruce and fir trees. While seabirds and eider ducks spend a majority of their lives at sea, nesting islands are essential for their survival. Each spring and early summer, the birds return to these special places to nest and raise their young. The smaller islands with the grass/forb/shrub component receive the greatest use by nesting seabirds and waterfowl. Today, approximately 500 islands are documented as seabird nesting islands. Along with the right component of nesting habitat, from rock crevices to fields of raspberry bushes and tall grasses, the best islands used by seabirds all lack mammalian predators (i.e. raccoons, foxes, and mink) and human disturbance during the nesting season.

We are indeed fortunate that many of Maine’s important nesting islands are owned by public and private conservation agencies. Individuals from and represented by these agencies deserve much praise for their wisdom and efforts in protecting these special places for the wildlife and for all of us to enjoy. In addition, seabirds nesting on several privately-owned islands have benefited from the generosity of landowners who are good stewards themselves. There are numerous examples of private individuals who have donated or sold their islands to conservation groups or have conferred conservation easements on their properties.

Maine’s islands provide nesting space for 13 species of seabirds whose population status, distribution, and nesting habitat needs vary greatly. Some species occur in relative abundance on numerous coastal islands, (common eiders, great black-backed and herring gulls and double-crested cormorants), and these populations appear healthy. Populations of common, arctic, and roseate terns declined during the last century but have begun to improve over the last 3 decades due to management programs and habitat protection. The other six species using our coastal islands include Atlantic puffins, razorbills, black guillemots, Leach’s storm-petrels, great cormorants, and laughing gulls. Populations of these birds may be secure, but each requires unique management and long-term population monitoring. Maine’s coastal islands are also home to numerous species of shorebirds, bald eagles, great blue herons, harbor seals, and more. These wildlife species are truly Maine’s island treasures!

--R. Bradford Allen, Wildlife Biologist, Maine Department of Inland Fisheries and Wildlife

Shorebird Areas
Shorebirds represented in Maine include sandpipers, plovers, turnstones, godwits, curlews, dowitchers, and phalaropes. Thirty-six species of shorebirds have been reported along the coast of Maine. Most of these species nest in the Canadian arctic and sub arctic regions and begin their migration to southern wintering areas in July. Along with the Bay of Fundy, the Maine coast is recognized as a critical staging area for migrating shorebirds, these long distance travelers depend on coastal staging areas to accumulate the fat necessary to fly a nonstop, transoceanic flight to their South American wintering areas.

Shorebird staging habitats range from intertidal mudflats, to sandy beaches, to rocky intertidal areas. Food resources, consisting of intertidal invertebrates, and suitable roosting sites in close proximity to feeding areas, are the two most critical factors determining shorebird distribution. Each species has preferred feeding and roosting habitats. Species requiring sand and gravel beaches and saltmarsh (e.g. yellowlegs, willet, sanderling, and others) are more commonly found in Saco Bay, Casco Bay, and Penobscot Bay. Eastern Maine offers highly productive intertidal mudflats attractive to semipalmated sandpipers, semipalmated plovers, black-bellied plovers, whimbrels, dowitchers and others. Feeding habitats such as inter tidal mudflats and saltmarsh panes provide shorebirds with high concentrations of invertebrates. Roosting habitats such as sand spits, gravel bars, beaches and rock jetties, are located above the high water mark providing migrating shorebirds a place to sleep and preen during high tide when feeding areas are inundated, thus reducing energetic costs and maintaining a positive energy flow. Coastal staging areas are susceptible to degradation from development and environmental contaminants. Human related disturbances such as ATV traffic and beachgoers disrupts foraging and resting time and causes birds to expend their energy reserves fleeing or traveling to alternative sites. Predation by foxes, raccoons, domestic cats and dogs can be especially limiting in areas of high human use and development.

To achieve management goals and objectives developed by a public working group, the Coastal Migratory Shorebird Management System was updated and reviewed by the Wildlife Division in April 2003. This document outlines criteria used to select a subset of shorebird feeding and roosting areas that is critical to migratory shorebirds in Maine. Presently, 96 roosting areas and 120 feeding areas qualify as “Areas of Management Concern.” These areas are designated as Significant Wildlife Habitat under the Natural Resources Protection Act (NRPA) of 1988. This legislation recognizes Significant Wildlife Habitat as a state natural resource worthy of protection. Maine Department of Inland Fisheries and Wildlife is responsible for defining and mapping shorebird staging areas for protection under this law. The Coastal Migratory Shorebird Management System also outlines recommendations to assist biologists and landowners cooperatively protect and enhance shorebird habitats and meet the goals and objectives developed by the public working group.

--Lindsay Tudor, Wildlife Biologist, Maine Department of Inland Fisheries and Wildlife

Grassland Bird Habitat
Grassland habitats, including pastures, hayfields, and abandoned fields provide habitat for several birds in Maine such as upland sandpiper (Bartramia longicauda, state-listed endangered), eastern meadowlark (Sturnella magna, special concern), horned lark (Eremophila alpestris), bobolink (Dolichonyx oryzivorus), grasshopper sparrow (Ammodramus savannarum, endangered), vesper sparrow (Pooecetes gramineus, special concern), savannah sparrow (Passerculus sandwichensis), northern harrier (Circus cyaneus hudsonius), and short-eared owl (Asio flammeus flammeus, special concern). In 1997, MDIFW surveyed 243 grassland/barren sites. In 1998, 127 additional sites were surveyed. Since those surveys were conducted, we have digitized habitat polygons around the sites as a preliminary step to mapping important grassland habitats in the state of Maine. In 2005-06, the U.S. Natural Resource Conservation Service (NRCS) provided funds to support revisits to the surveyed sites to confirm whether or not those areas still provide good habitat for grassland birds. The NRCS is interested in this data for assessing whether projects submitted for Farm Bill funding will benefit Maine wildlife. Staff from Habitat Group and a field technician hired with the NRCS funding have been re-surveying those sites in central, southern, and northern Maine. In addition to revisiting the previous sites, we also used the recently completed, updated landcover map to identify other potential sites and are conducting surveys of those sites. This project will continue in 2007 in downeast Maine with the intent of having a completed grassland habitats layer by the end of 2007.

--Don Katnik and Thomas P. Hodgman, Wildlife Biologists, Maine Department of Inland Fisheries and Wildlife

Rusty Blackbird Status, Ecology, and Habitat
The Rusty Blackbird (Euphagus carolinus) is a wetland-breeding blackbird of the boreal regions of northern North America. Formerly considered common, it has shown dramatic declines in numbers during the past century, with these declines accelerating since 1970. The cause of this continent-wide decline is not clear, although experts suggest several anthropogenic factors, including draining and conversion of wetlands in their wintering range, wetlands acidification leading to declines of invertebrate prey, and disturbance from landscape changes. However, none of these hypotheses clearly account for both the magnitude and prolonged duration of this decline. During the 2001-2002

Ecoregional Surveys, sponsored in part by the Maine Outdoor Heritage Fund, MDIFW biologists conducted roadside surveys of nearly 200 wetland sites in northwestern Maine. They found breeding Rusty Blackbirds at only 18 locations, and some of these were of just single singing males.

In late 2005, we began a study that will involve fieldwork during spring and summer of 2006 and 2007. This research involves a baseline inventory of the current geographic distribution and abundance of Rusty Blackbirds in Maine. These data will be used to a) examine the validity of state and regional population targets and b) to make recommendations for an effective monitoring program for this species on their breeding grounds. We also will compare current records (2005-2007) with past distributional information to evaluate whether the species’ well-documented decline has a) effected its distribution in Maine, and b) if populations show fidelity to known breeding locations. Finally, we will assess a) how habitat selection in Maine differs from that reported from elsewhere in North America, and b) compare habitat features at currently occupied breeding sites with other seemingly suitable potential breeding sites in the state, to test hypotheses on why this species has declined and what habitat management options exist to aid in its recovery. A graduate student from the University of Maine will be fieldwork for this project. This work is being supported by Outdoor Heritage Funds, Conservation Plate Funds, Pittman Robertson Funds, and the University of Maine.

--Thomas P. Hodgman, Wildlife Biologist, Maine Department of Inland Fisheries and Wildlife

Submitted by : Mark Latti, DIFW

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NOTE - This article reflects the views of the author and not necessarily those of the TRC Alliance Team.