nodes only. We did not have deer die within two months of
capture from natural causes or capture myopathy.
Deer mortalities resulted from predation (coyote (n
=
5)
and mountain lion (n
=
5)), vehicle collision (n
=
3), hunt-
ing outside of Wind Cave National Park (n
=
5), lethal
removal by law enforcement (n
=
4), and unknown causes
(n
=
6). Testability for CWD (19/28, 68%) and number of
CWD-positive (8/19, 42%) deer varied by source of mortal-
ity (Table 1). Predation by coyotes and mountain lions was
the primary mortality factor and also the least likely to be
able to be tested for CWD (50%) because tissues necessary
for sampling were no longer present due to consumption
or scattering. Unknown causes, the second most com-
mon source of mortality, resulted from carcasses that were
not testable (50%). Deer mortalities from human-derived
sources (vehicle collisions and hunting) were more likely
than other sources of mortality to provide a sample for
CWD testing (
χ
2
=
4.47, p
=
0.03) than those from preda-
tion events. Females were six times more likely than males to
be killed by a predator than by a human source (OR
=
6.67,
p
=
0.078). There was no apparent age bias by mortality type,
but our study population was primarily adult animals. If
only mortalities were tested, observed CWD prevalence was
42%. Observed prevalence from human-induced mortalities
only was 20%. No carcasses had indications of malnutri-
tion, apparent disease, or heavy internal or external parasite
loads. A few deer had positive titers for all serum tests, with
the exception of Johne’s disease, throughout the three years
of study (Table 2); there was no difference between sexes.
Exposure to EHD (13%) was most commonly identified,
followed by WNV (12%), MCF (11%), BT (11%) and
1 individual identified with antibodies to BVD. None of the
Table 1. Cause-specific mortalities of 28 deer (of 67 collared) at
Wind Cave National Park, South Dakota, USA, from February 2003
to December 2005 and chronic wasting disease (CWD) status of
testable samples, either CWD-positive (+), CWD Non-detect (–), or
Non-testable.
MORTALITY
CWD +
CWD –
Non-testable
Coyote
1
3
1
Mountain lion
0
1
4
Vehicle collision
1
2
0
Hunting outside study area
1
3
1
Lethal removal in study area
3
1
0
Unknown
2
1
3
