Wildlife Action Plan Cover Type mapping of the MBHA
SHORT REPORT
On
Mink Brook Highlands Area Wildlife Habitat Mapping
Hanover, NH
Seven field site visits to the 613-acre Mink Brook Highlands Area (“MBHA”) have taken place to date.
The MBHA is defined by the southern boundary of the Hanover Town Line on the south, Mink Brook on
the north, Great Hollow Road on the east, and Route 120 on the west This area was established by the
Hanover Planning Department and further defined in the field using a Garmin 12XL GPS unit, (precision,
3.2 – 7.8 m). The calculation of the tract size was completed using ArcMap 9.2 GIS software by ESRI.
With the exception of 187-acres in the central portion of the tract where property access permission
was denied, all areas of the MBHA were visited. Field dates have been August 29, October 8, October 16,
November 5, November 11, 2008, March 10 and April 1, 2009.
Wildlife species lists that were initially provided in November have been updated to include 28 species
of mammals, 67 species of birds, 3 species of fish, 1 reptile and 8 species of amphibians. The combined
total number of vertebrate species that likely occurs in this area is 185, comprised of 35 mammals, 129
birds, 3 fish, 5 reptiles, and 13 amphibians. Roughly 58% of the probable vertebrate species have been
seen to date.
During the winter season, two days of track transects yielded 15 species of mammals, which were in
order of dominance: white-tailed deer, red squirrel, fisher, coyote, raccoon, red fox, snowshoe hare,
gray fox, Peromyscus mouse, porcupine, gray squirrel, ermine, short-tailed shrew, mink and river otter.
Because of conditions, no quantitative accounting of frequency was possible. Analysis of track and nontrack sign, however, allowed for an estimation of habitat usage within the study area. For example,
whereas white-tailed deer were widespread
throughout the MBHA, fisher, porcupine,
mink and otter were mostly found in the
bouldery eastern part, and red fox, starnosed mole, and coyote were found more
commonly in the rolling, stone-free western
part. Exceptions were found among all
species, but the general trends reflect the
very different habitat conditions present
from east to west.
Old male fisher seen lumbering through the
eastern part of the Mink Brook Highlands Area
VdP/EMC
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April 2009
Wildlife Action Plan Cover Type mapping of the MBHA
In order to provide a basis for estimating habitat usage by vertebrate wildlife in the Mink Brook
Highlands Area, the cover type map for the MBHA was revised to reflect wildlife habitat types according
to the Wildlife Action Plan or WAP. This document, published in 2005 by the NH Fish & Game
Department, provided a series of statewide maps that contained wildlife habitat types, habitat
condition, and significant focus areas for conservation. The attached 8.5” x 11” map demonstrates the
difference between the statewide coverage as clipped to the study area and the habitat types identified
in the field during the above listed field dates.
The significant difference between the two maps is the more discrete nature of the field-based map
relative to the common habitat types present. Each of the five common habitat types – hemlockhardwoods, Appalachian oak-pine, developed or barren, peatland, and marshes – were mapped in
closer proximity of where they actually are on the ground. In addition, four unmapped types were added
to the MBHA: floodplain forest, lowland spruce-fir forest, northern hardwood forest, and ridge-talus.
These were found in certain sections of the MBHA, with all of the floodplain areas observed along Mink
Brook, the lowland spruce-fir forest found behind Hypertherm, the northern hardwood forest found
mostly in the higher elevation areas with ‘sweet’ soils, and the ridge-talus areas found in the eastern
bouldery part of the MBHA.
The aforementioned map also includes a listing of grasslands and cliffs. Although outside of the MBHA
study area, grasslands are shown for the upper Mink Brook floodplain area on the statewide coverage
map. In the field, this area appeared to be mostly marshland as created by beavers over the past several
decades. In terms of cliffs, while there were several cliff areas found in the eastern part of the MBHA,
these were too small to map. For guidance as to the location of many of these 10 – 40 foot high steep
ledge areas, it is suggested that the reader look to the edges of the ridge-talus units in order to
approximate their location.
As noted in the April 8, 2009 presentation to the Town of Hanover, it is incumbent on the Town to “fill in
the gaps” on the two properties where property access permission was denied. It is clear that there are
more discrete units of habitat within this area, as suggested by at least two members of the audience
who have been to these locales. According to one source, the complexity of habitat types that is present
in the eastern part of the MBHA, particularly the ridge-talus habitat, finds its western boundary along
the central north-running brook. Given the rich nature of the soils in this area, it is likely that patches of
northern hardwood forest will likely be found in this area as well.
Over the course of the next few months, additional data on wildlife occurrences, notably birds, will be
tallied and assessed in order to provide a clearer indication of where sensitive habitat exists. Areas that
can be labeled as “significant ecological areas” or SEA’s, will be identified on the habitat map in order to
derive the 3-level wildlife impact category map, namely, those areas that reflect the following
categories:
1. No-disturb areas with high habitat value
2. Minimal disturbance areas with lower habitat value
3. Previously disturbed areas with low habitat value
VdP/EMC
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April 2009