Examination of the Tick Burden on Sika Deer
In Dorchester County, Maryland
M. Chad Smith1, David Kalb2, Sean Q. Dougherty2, Matthew Muma2, Dr. Jacob Bowman2, Dr. Thomas Lambert1
1, Frostburg State University Wildlife Biology Department. 2, University of Delaware Department of Entomology and Wildlife Ecology
http://www.unboundground.com/BigTicks.pdf
Introduction
Sika deer (Cervus nippon - yakushimae) are native to the
Japanese Islands and were introduced to Maryland’s eastern
shore in 1916. Since then, they have increased in number to
an estimated 5,000 - 10,000. Although mainly centered in
Dorchester County Maryland, sika deer have expanded
their range to include Wicomico, Somerset and Worchester
Counties (Maryland DNR 2009).
The MD Department of Natural Resources (DNR) strives to maintain this
population and increase it where possible (Eyler and Timko
2008). Understanding the overall ecological niche that Sika
deer occupy is important for implementing herd
management strategies. Ticks are parasitic to deer and
infestation can affect the overall health of deer. Ticks are
vectors for Lyme Disease and Meningoencephalitis which
can affect humans through exposure to tick bites. Currently
the DNR is conducting a study on the dispersal range of
juvenile stags using radio collars and bi-angulation. This
project is monitoring the distance year old stags move from
their capture area. Ticks were a secondary objective in each
capture. These projects are taking place on the Tudor Farms
Property, located to the Northeast of Blackwater NWR.
Tick burdens were determined on live sika deer and related
deer age and size. 2 species of tick (Ammblyomma
americanum the Lone Star; and Ixodes scapularius the Deer
Tick), were found on the deer examined in this study.
Study Area
Dorchester County MD is primarily forested (41%) with large tracts of wetlands (25%) and
agriculture (30%). Less than 5% is developed (Comprehensive Coastal Inventory Program
2003). Blackwater National Wildlife Refuge and Fishing Bay Wildlife Management area make up a
large portion of the center of Dorchester County. The study took place on private land, The
Tudor Farms, located along the Chicamacomico and Transquaking Rivers to the Northeast of
Blackwater. Future study areas may include the TarBay Hunt Club property located on the
Chesapeake Bay, two miles north of Hooper’s Island on Meekin’s Neck to the west of
Blackwater NWR. Habitat at the Tudor Farms and TarBay Hunt Club is a mix of tidal salt marsh
and hard/soft wood forests. The open marsh habitat is exposed to high amounts of
sunlight in the middle of the marshes where there is no forest canopy or tree-line
shading.
Methods
Deer were captured during February and March 2009.
Drop nets and Clover (Box) traps baited with corn were used.
Net capture activities were focused at night while box traps were checked twice daily.
All deer captured were ear tagged & the animal’s age, sex and weight were determined.
The anterior region of each deer was examined for ticks. All observed ticks were collected for later
species level identification.
Results and Discussion
During February and March 2009, Ten Sika Deer
were captured (2 Juvenile Stags, 1 Adult Stag; 3
Juvenile Hinds, 4 Adult Hinds) and examined for
ticks.
The difference in tick burden may relate
to differential use of habitat as deer age. Ticks
were found on 4 of these 10 deer.
Deer with ticks were significantly older
(Mean=22.5 months S.D.= 6.5) than deer without
ticks (Mean= 14 months, S.D.=2.82) (Tobs=
3.374, d.f.=8, p=0.034). Additionally, deer with
ticks were significantly larger (Mean=54.75 kg,
S.D.=21.98) than deer without ticks (Mean=25.83
kg, S.D.=7.17) (Tobs=3.537, d.f.=8, p=0.034).
The older deer have spend greater amounts of
time in fields and forest edge-lines, increasing
tick predation. These edge areas are dryer and
more conducive to tick populations. As animals
mature more time is spent in this habitat rather
than the wet habitat of the marsh, resulting in
high tick burdens on older deer.
Acknowledgements
• University of Delaware Department of Entomology and Wildlife Ecology
• The Maryland Department of Natural Resources Wildlife Heritage Division;
Mr. Brian Eyler
• Frostburg State University Biology Department;
Dr. Wayne Yoder, Dr. Tom Lambert.
• Mr. Paul Tudor Jones, The Tudor Farms, Tudor Staff of Dorchester County, MD.
• Mr. Phil Green and Mr. Bob Smith of TarBay Hunt Club Inc., Dorchester County, MD
Objectives
• Assist the Main DNR Deer Project
• Determine the tick species present on Sika deer.
• Relate tick burden to deer age and size.
Sika Deer
Lone Star Tick
Amblyomma americanum