HomeMy WebLinkAboutAwerbuch, T DEIS.pdf HARVARD SCHOOL OF PUBLIC HEALTH
Department of Global Health and Population
To: Village of Cayuga Heights Board of Trustees
December 14, 2010
Subject: Draft Environmental Impact Statement — Cayuga
Heights Deer Management Plan
Dear Board of Trustees,
I am a scientist and teacher at the Harvard School of Public Health in
the Department of Global Health and Population.
http://www hsph harvard edu/research/tamaraawerbuchfriedlander/in
dex.html.
One of my main contributions to science is my research on the
ecology of the vector that transmits the Lyme disease bacteria, which
appeared in peer reviewed publications in scientific journals.
The essence of my findings is also described in the home page of my
school:
http://www hsph harvard edu/news/features/features/kiIing-deer-not-
answer-reducing-Iyme-disease.html.
After reading your DEIS pertaining to potential outcomes of
management programs to reduce tick populations by killing deer, I
was surprised at the lack of a scientific basis, moreover at the
incorrect assumptions about the relationship between deer and the so
called "deer tick"; the scientific name of blacklegged ticks is /xodes
dammini, the name given by Dr. Andrew Spielman, a colleague in our
school, who discovered that this is the vector of the disease.
The life cycle of the tick is quite complex, it is only The adult tick that
takes a blood meal from deer, lays eggs and then dies. Deer do not
carry the agent of Lyme disease; the white-footed mice do.
In Crane Beach [in Ipswich, MA], where I conducted my study,
people thought that if they killed deer they would reduce the number
of ticks, and thereby control Lyme disease. Deer were reduced [from
around 400 in 1983 to just over 100 in 1991], but Lyme disease kept
665 Huntington Avenue Boston,Massachusetts 02115 Fax: 617 432-6733
growing. The question was why? We killed deer but people still got
Lyme disease.
So I did a study using a mathematical model to capture the life cycle
of the tick. Because the ecology of Lyme disease is so complex, it is
very hard to look at deer and tick, mouse and tick, one by one. You
have to link all the factors together in a way that lends itself to
mathematical analysis.
The following figure shows the reduction in deer number throughout
the years, and the line shows the increase in larvae ticks in Ipswich,
Mass.
Deer Larvae fbillionsl
500 l 160
F 1 140
400 -� 120
100
I60
200 flwlu
� 5C
- a0
100
20
I
0 C
1983 1984 1985 1986 1987 1988 1969 1990 1991
Larvae (Sep) M Deer
The larvae pick up the infection from infected mice, and those that do
not die, molt into infected nymphs which are the ones that transmit
the infection.
So there is NO LINEAR correlation between killing deer and the tick
population.
On Monhegan Island it was possible to get totally rid of the tick
population because ALL deer were killed and no other animals were
there to take over the empty niche left by the deer to support the adult
tick.
So in summary, there is NO scientific justification for a deer killing
program in your community of Cayuga Heights, NY. There are
certainly alternative ways for reducing the risk of Lyme disease.
As we saw using data from Ipswich Mass. where there was an
attempt to reduce the risk of Lyme disease by killing deer over a
period of about ten years , I was able to show with a mathematical
model why this intervention did not work.
Dr. Tamara Awerbuch
Department of Population and International Health, Harvard School of
Public Health
655 Huntington Ave
Boston MA 02115
Phone: 617-432-2505
Fax: 617- 432-6733