Illinois Natural History Survey Reports

              1
R e p o r t s
September/
October 1996
No. 341
I N S I D E
Using Biological Con-trol
to Lose Loosestrife
in Illinois
2
Web Collaboration (Ar-boriculture
On-line)
3
Interbasin Dispersal of
Invading Aquatic
Species
4
Species Spotlight:
Bobcats
6
The Naturalist's
Apprentice:
Going Around in Circles
7
Can We Restore Elk to Southern Illinois?
Continued on back page
I LLINOIS
NATURAL
HI STORY
S U R V E Y
Illinois is at the center of the his-torical
range of the eastern race of
North American elk (Cervus ela-phus
canadensis). This subspe-cies
is now believed to be extinct,
having been extirpated in Illinois
by 1850. Existing wild popula-tions
of elk occupying the former
range of eastern elk (principally in
Michigan and Pennsylvania) are
descendants of Rocky Mountain
elk (C. e. nelsoni), translocated
from the area near Yellowstone
National Park.
In the fall of 1995, members of
Illinois’ General Assembly direct-ed
the Illinois Department of Nat-ural
Resources (DNR) to study the
feasibility of reestablishing a wild
population of elk in Illinois. Elk
reintroductions have been tried
many times, but success has been
varied. Most failed attempts have
been due to poor-quality habitat
and land use/land owner confl icts.
Successful reintroductions require
large amounts of high-quality
habitat and low human density.
Three of 8 attempts succeeded in
the plains states (Oklahoma, South
Dakota, and Texas) while only 2
of 10 attempts succeeded in the
East (Michigan and Pennsylva-nia).
The research by the Illinois
Natural History Survey (INHS)
was intended to provide resource
managers in the DNR with a pre-liminary
assessment of the habitat
available to support a reintro-duced
population of elk in south-ern
Illinois and identify promising
release sites relative to habitat,
land ownership, agriculture, and
road densities.
The Illinois Geographic In-formation
System (GIS), which
is housed at INHS, was used to
identify elk habitat in southern
Illinois. GIS is a sophisticated set
of computer programs designed to
manipulate, process, and analyze
map data. The map data we used
came from aerial photography and
remote sensing, most of which
Potential elk habitat in southern
Illinois.
was generated for other Survey
projects. Using the programming
expertise of INHS scientists Tony
McKinney and Mark Joselyn, we
fi rst “told” GIS what elk habitat
should look like and then “asked”
it where similar habitat existed in
southern Illinois.
Published studies of elk habi-tat
use indicate that a 50-50 mix
of foraging areas (grasslands and
shrubby areas) and cover (forests)
is optimal. Other factors must be
considered when selecting poten-tial
release sites. For example,
elk are very sensitive to human
disturbance, so road densities
must be low and human activity
must be minimal. Elk also need
lots of room, so isolated areas
that have a suitable mix of forage
and cover with low human dis-turbance
may still be poor habitat
because they are too small.
Given these criteria, our anal-ysis
indicated that, not surpris-
Elk bull (Cervus elaphus nelsoni)
at Yellowstone National Park.
Photo by Tim Van Deelen, INHS Center for Wildlife Ecology
Map by Tony McKinney, INHS Center for Wild-life
Ecology, Geographic Information System
Lab