Photo courtesy of The Nature Conservancy
Portions
of Iowa, Wisconsin, Minnesota and Illinois contain unusual geology.
The karst region, referred to as the “Driftless Area” escaped
the last glaciers leaving the Paleozoic age (500,000 year old) bedrock
subject to erosion. In addition to the curious topography of steep slopes
and cliffs, there are unique habitats, the algific (cold air) talus
(loose rock) slopes. These slopes remain cool throughout the year and
are home to rare species of plants and animals. Established in 1989, Driftless
Area National Wildlife Refuge is helping to recover two federally
listed species: the endangered Iowa Pleistocene snail and threatened
Northern monkshood. Although the Refuge was established to protect the
snail and flower an entire rare community of plants and animals is preserved
on these sites. States, counties, and private organizations like The
Nature Conservancy also help to protect algific
talus slope sites.
What Can I Do to Help Prevent the Extinction of Species?
Learn more about northern monkshood and other endangered and threatened
species. Understand how the destruction of habitat leads to loss of
endangered and threatened species and our nation's plant and animal
diversity. Tell others about what you have learned..
Write to the U.S. Fish and Wildlife Service or your state conservation
agency to learn more about endangered and threatened species and to
voice your support.
Join a conservation group. Many have local chapters.
Saving Snails and Monkshood
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A
tiny snail, a relict from the ice age finds home on a cool rocky slope,
near the coldwater streams, cliffs, valleys, and sinkholes that make
up the Driftless Area National Wildlife Refuge in Iowa. The endangered
Iowa Pleistocene snail (Discus macclintocki) has known the meaning of
refuge in more ways than one. Known from fossil records to have existed
400,000 years ago, it is one of many glacial relict species that found
refuge in the region of northeast Iowa, northwest Illinois, southeast
Minnesota, and southwest Wisconsin called the driftless area. The rugged
driftless area was so called because of early geologist’s inability
to find glacial drift. Much of the area was indeed covered by glaciers
about 500,000 years ago. The Iowa Pleistocene snail found its current
home with desirable temperature, moisture, and food resources about
10,000 years ago as ice age conditions moderated. Certain slopes, usually
north facing, have loose rock that allows ice-cooled air to exit from
underground cracks and fissures. Upland sinkholes contribute to the
air flow regime and are an important component of a unique system called
an algific talus slope, meaning cold producing rocky slope. Even when
outside air temperature is 90 degrees, ground temperatures on these
slopes can be close to freezing. This air flow provides a climate similar
to what was prevalent in glacial eras. Freezing winter temperatures
are moderated on the slopes giving a year round range of about -10 to
10o C (14 to 50o F).
The Iowa Pleistocene snail now occurs nowhere else in the world but
37 algific talus slopes in Iowa and Illinois. The Iowa Pleistocene snail
was thought to be extinct until discovered in 1955 by a scientist working
in northeast Iowa. It was listed as endangered in 1977. It is no bigger
than a shirt button with adults ranging in size from 5 to 7 millimeters
in diameter. They live in the leaf litter preferring a diet of birch
and maple leaves. The snail shares its habitat with a host of rare and
disjunct plants and animals associated with cool habitats. Balsam fir
(Abies balsamea), Canada yew (Taxus canadensis) and yellow birch (Betula
alleghaniensis)are common to algific talus slopes. The threatened Northern
monkshood plant (Aconitum noveboracense) also grows on these sites.
More abundant on approximately 114 sites in Iowa, Wisconsin, Ohio and
New York monkshood also grows on similar cool moist habitats like sandstone
cliffs. The majority of sites are in Iowa. The perennial monkshood is
a member of the buttercup family and derives its name from the hood
shape of its zygomorphic flowers adapted for bumblebee pollination.
The 775 acre Driftless Area National Wildlife Refuge was established
in 1989 to permanently protect populations of the Iowa Pleistocene snail
and threatened Northern monkshood. These species’ habitat cannot
be restored once lost and the primary objective of their respective
recovery plans is providing protection for remaining colonies. Concern
over threats to the habitat stemmed from logging, grazing, filling of
sinkholes, agricultural runoff, roads and quarries. The invasion of
garlic mustard (Alliaria petiolata) onto algific talus slopes has emerged
as a threat in recent years. And no one knows the potential effects
of modern global warming.
The Refuge consists of scattered tracts of land in northeast Iowa ranging
from six to 208 acres. Algific talus slopes range in size from a few
square meters to perhaps ½ mile in length. More than just the
algific talus slope is targeted for acquisition. Sinkholes that feed
the system can occur some distance away from the slope and need protection
to ensure long term integrity of the site. Buffer areas around the slope
are included when possible. The Refuge contributes to lands already
protected by The Nature Conservancy, the Iowa Department of Natural
Resources, County Conservation Boards in Iowa, and publicly owned sites
in Ohio and New York. Further acquisition is planned to reach recovery
goals.
At least eight other snail species, considered glacial relicts, are
also protected on these sites. Some of these species like the midwest
pleistocene vertigo (Vertigo hubrichti hubrichti), are even smaller
and perhaps more rare than the Iowa Pleistocene snail. Protection of
algific talus slopes may help prevent the need for threatened or endangered
status for these snails and plants like the golden saxifrage (Chrysosplenium
iowense).
There are over 300 algific talus slopes in Iowa, with varying species
components. Not all slopes have all of these species. Some may not have
federally listed species and are more conducive to protection by local
agencies and groups. Private landowners are the stewards of many algific
slopes. The FWS works with landowners with federally listed species
on their property to exclude cattle or prevent other disturbances to
the sites.
Of course, the goal is recovery. To gauge progress over the years,
monitoring of Northern monkshood is conducted and we are experimenting
with monitoring methods for the Iowa Pleistocene snail. A mark recapture
study was initiated in 2000 with the assistance of Iowa State University.
The Nature Conservancy of Iowa placed an intern at the Refuge office
this year to conduct monitoring for both species and TNC preserves.
The Iowa DNR has assisted with monitoring and identification of acquisition
sites. With all of these efforts and barring extensive global warming,
these species can someday be recovered as representatives of ice age
history.
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Photo by Gary Tonhouse
The northern monkshood is
a threatened species.
Threatened species are animals and plants that are
likely to become endangered in the foreseeable future.
Endangered species are animals and plants that are in
danger of becoming extinct. Identifying, protecting,
and restoring endangered and threatened species
is the primary objective of the U.S. Fish and Wildlife
Service's endangered species program.
Scientific Name - Aconitum noveboracense
Appearance - Northern monkshood is noted for its very distinctive,
blue hood-shaped flowers. The flowers are about 1 inch in length, and
a single stem may have many flowers. Stems range from about 1 to 4 feet
in length. The leaves are broad with coarse, toothed lobes.
Range - Northern monkshood has only been found in Iowa, Wisconsin,
Ohio and New York.
Habitat - Northern monkshood is typically found on shaded to partially
shaded cliffs, algific talus slopes or on cool, streamside sites. These
areas have cool soil conditions, cold air drainage or cold groundwater
flowage. On algific talus slopes, these conditions are caused by the
outflow of cool air and water from ice contained in underground fissures.
These fissures are connected to sinkholes and are a conduit for the
air flows.
Reproduction - Northern monkshood is a perennial and reproduces from
both seed and small tubers. The flowers bloom between June and September
and are pollinated when bumblebees pry open the blossom to collect nectar
and pollen.
Why is the Northern Monkshood Threatened?
Habitat Loss or Degradation - Threats to northern monkshood include
contamination and filling of sinkholes, grazing and trampling by livestock,
human foot traffic, logging, maintenance of highways and powerlines,
misapplication of pesticides, quarrying and road building.
Collection - Some populations have been adversely affected by scientific
collection.
What is Being Done to Prevent Extinction of the Northern Monkshood?
Listing - Northern monkshood was added to the U.S. List of Endangered
and Threatened Wildlife and Plants in 1978.
Recovery Plan - The U.S. Fish and Wildlife Service has developed a
recovery plan that describes actions needed to help the plant survive.
Research - Many northern monkshood populations are being monitored
to determine long-term population trends. Genetic studies are being
conducted so population differences can be better understood.
Habitat Protection - A variety of government and private conservation
agencies are all working to preserve the northern monkshood and its
habitat. Voluntary protection agreements have also been made with some
private landowners.
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