YALE PROF. SCHMITZ
FALLS SHORT ON DEER CONTAINMENT
January 25th 2005: Report from the Fairfield County Municipal Deer Management
Alliance by Vice Chair,
Georgina Scholl, on the talk given by Prof Schmitz, of the
Yale School of Forestry and Environmental Studies, to the Ridgefield Deer Committee.
by Dr. Georgina Scholl
much anticipated talk by Prof Oswald Schmitz to the
Ridgefield Deer Committee on January 24th, was ultimately, a
disappointment in terms of any real alternatives to lethal hunting of the deer.
He did however leave the Committee with some concrete suggestions for
up a deer culling program in a scientific manner with defined goals and
measurable end points.
He began his talk with an appeal for the use of real science and
integrity to back up any proposed plan. He explained that there are now
over 150,000 deer in CT, and that as biodiversity loss is correlated
with the rise in the deer population, it is hard to say whether the deer are
the cause or the consequence of the declining ecosystem health that we
all observe and none now deny. One solution that he offered that did
not require hunting was to let Nature take its course: “Death due to
starvation is Nature’s way of reaching an ecological balance: survival
of the fittest.” Schmitz went on to acknowledge all of the previously
debated issues in the arena of deer management-
Is there really a deer problem?
Yes, if the residents feel they have too many deer/vehicle accidents a year,
an unacceptably high incidence of Lyme disease, and significant visible
damage to their woodlands and decorative plants.
Is the damage we see to the understory in fact due to deer browse, or to
maturation of the forest canopy? Prof Schmitz explained that the forest
is in a transitional phase in all of Fairfield County, being about 150
years old since the clear cutting of the18th century. At this phase a
forest has low diversity of animal species and a higher carrying
capacity for deer, hence a high deer population. It would take another
50 years to reach a mature phase of forest, which will not happen in
the presence of ongoing development of woodlands and the current land
use practice of homes with open lawns. Unless we are prepared to “think
about changing the landscape” which he agrees is “a difficult and
critical issue to deal with” then we “will be permanently stuck in a
transitional forest growth pattern.
it the deer or the white-footed mice that should best be targeted?
This question was raised by an audience member. It was explained by a
committee member that while the mice admittedly play an important role,
they do not play an exclusive role (their role in the life-cycle of the
tick can be equally well performed by chipmunks and other small mammals
and by small birds). In semi-rural and suburban Connecticut it is the
deer that plays a role with no understudy, facilitating reproduction of
the adult ticks. Thus the deer is the one vulnerable point in the
tick’s life cycle; hence reducing the deer population is a critical
means of reducing tick density, which in turn reduces the rate of Lyme
Thus Schmitz cleared the way for the real debate to begin: “What are
the goals of the community? And how will they be measured?”
Unfortunately it is almost impossible to perform accurate deer counts,
so indirect measures of assessing deer densities are used instead. At
the suggestion of the committee, he offered a group of his masters
degree students to perform research in Ridgefield. They would
gather data for a GIS map which Ridgefield currently does not have.
This data would form the basis for a future data base to measure
Several possible goals were discussed: Eradication of Lyme Disease, or
alternatively, reduction of incidence of Lyme cases to a certain level;
reduction of deer/vehicle accidents to an acceptable annual rate; and
reduction of visible deer browse in the woodlands and parks. Each of
these goals has its own targeted density of deer per square mile and
has a scientifically measurable way of assessing it. Therefore an
end-point can be chosen and achieved. Prof Schmitz emphasized that he
does not like to see hunting used as a short-term solution, but instead
as part of a long-term plan. That might include other measures, such as
reduction of total lawn areas and rethinking land use patterns, such
that there might be areas in town where deer were allowed to feed.
“It is unfortunate that we have inadvertently
created an ideal habitat for
a large deer population with vast amounts of edge habitat.”
The talk was well attended by committee members and public alike,
including representatives concerned with deer management from Weston
and Redding. Information provided by Prof. Schmitz will undoubtedly
influence the Ridgefield Deer Committee's recommendations and those of
surrounding communities. A copy of the presentation will be available
at the Ridgefield Public Library in VHS format.