Statistical tests comparing a number of subsamples of both wolf-killed
deer and hunter-killed deer showed a series of significantly different
sex ratios (tables 1-3). The ratio of males to females in the fawn
cohort of the hunter-kill, which is probably the most representative of
the actual fawn sex ratio, was even (table 2). With wolf-kills,
however, a significantly higher percentage of females was taken in the
fawn subsample (59 percent) than in the adult subsample (46 percent).
These results compare favorably with those of Stenlund (1955), who
found that from 1948 to 1953 in the same area as the present study 68
percent of 19 sexable fawn wolf-kills were females and 44 percent of 63
sexable adult wolf-kills were females.
If the sex ratio of fawns began even, and more females than males were
killed by wolves, then a higher proportion of males would be left in
the adult population, unless some other mortality factor kills more
male fawns. Thus it is not surprising that in the wilderness area,
where little or no hunting is done, the sex ratio of wolf-kills in the
adult cohort is significantly heavy toward males (71 percent: 29
percent). This was also true of the wolf-kills in Algonquin Provincial
Park, where males made up 57 percent of the total sexable wolf-kill
(Pimlott _et al._ 1969). The latter figure may even have been higher if
calculated for adults alone, for a preponderance of female fawns in the
Algonquin Park data (such as occurred in our and Stenlund's samples)
would tend to obscure the preponderance of males in the adult sample.
The adult subsample of hunter-kills also contained a higher percentage
of males (66 percent : 34 percent). Although this might also reflect
the influence of wolf predation on female fawns, it probably is more a
result of the greater movement of bucks during the hunting season,
which overlaps with the rutting season. Even the sex ratio of adult
deer killed in wolf-free areas shows a preponderance of males (Erickson
_et al._ 1961).
However, it appears that the higher harvest of bucks by human hunters
does markedly affect the sex ratio of the deer population in the hunted
area, for the wolf-kill of adults in that area contained a
significantly higher percentage of does (56 percent) than did the
wolf-kill of adults in the wilderness area (29 percent).
Evidently the hunter harvest is not heavy enough to affect the age
structure of the deer population to any marked degree, for no
significant difference in age structure was found between the wolf-kill
in the hunted area and that in the wilderness area (table 1). This does
not conflict with the conclusion that hunting affects the sex ratio of
the deer herd, because it would take much less to influence a
population characteristic having two classes (sex) than one having 14
(age).
One additional difference in the sex ratio was found between two other
subsamples of the wolf-kill--that is, the wolf-kill before and after an
unusually high snow accumulation, which reached its peak about February
1, 1969 (table 1). Of a total of 77 animals killed before this snow
condition occurred (including those from previous years), 38 percent
were females. Of 44 animals killed after the heavy accumulation, 57
percent were females. One possible explanation for this is that females
may normally be less vulnerable to wolf predation, for Kelsall (1969)
has shown that they probably have a lighter weight-load-on-track than
males. Thus when snow conditions changed greatly, making deer generally
much more vulnerable to wolves (see Mech _et al._, p. 35), a
preponderance of does suddenly might have become available. There is
some evidence that does may be generally less vulnerable under most
conditions, for all seven of our wolf-killed deer over 10 years old
were females, and the oldest was over 14.