(MSWord copy of this article)
The Wolf and the Spread of Disease by N. Nazarova
Translated from the Russian Hunting and Game Management
November, 1978, Pages 24, 25
Although there has been much attention directed
towards the "predator--prey" biocenosis (i.e., intertwined existence),
there isn't yet a unified view of the role of the predator: some
researchers are trying to prove the existence of a balance in this
biocenosis and ascribe to the predator the leading role in determining
the number of prey; others propose that the number of predators is
relatively small and that they don't cause tangible harm to the numbers
of "useful" animals as opposed to the "harmful" ones.
Many propose that the wolf limits the numbers of
hooved animals (Naumov, 1933; Semyonov-Tyanshanskij, 1948, 1969; Druri,
Terletskij, 1962; Markidin, 1968; Komarov, Lavrov, 1969; Kheruvimov,
1969 and others).
The existence of diametrically opposed viewpoints
speaks to the complexity of the problem and its incomplete research.
Turning to the question of the role of wolves and
other predators (fox, polar fox, wolverine, etc.) in the spreading of
infectious diseases it should be stressed that here, too, there is
incomplete research. However, there are in the literature many
reports of a percentage of observed wolves being the carriers of
infectious diseases (brucella, deer-fly fever, listerosis, anthrax, and
others), reports which provide a strong basis to think tha the predator
plays an important role in their spread. It is most likely that
this highly mobile predator ranging over dozens of miles is able to
spread these diseases over significant distances.
Within the last few years wolfpacks have formed,
which in order to survive, have been drawn to carrion, especially to
dead cattle pits where the carcasses of the dead cows have not been
properly buried despite the clear directives of veterinary
medicine. In such situations these wolf carrion-eaters prove to
be extremely serious spreaders of infectious diseases.
The wolf has been blamed for instances of the
extremely severe diseases of both domesticated animals and man --
rabies. Lupine rabies after a latent period manifests itself in
extreme agitation and aggression. Within a very short time such a
dangerously sick wolf can widely spread out of his area of
activity. For example, there is a recorded episode of just such a
spread of rabies among farm animals and people in Belarus in 1957 when
a rabid wolf within just a day and a half roamed over a hundred miles,
bit 25 people (19 seriously), some 50 farm animals, and who knows how
many forest creatures (Lin, 1962). Similar happenings are not
rare. Moreover, while recognizing the undoubtedly serious role of
the wolf in the spread of the rabies virus to man, one must be
cognizant of the incomplete research in the wolf's role in limiting the
numbers of other carriers of this disease, namely, the fox. The
most recent examples of epizootic rabies (i.e. rapidly spreading) in
Europe have occurred after the wolf was long gone, in the western
regions of Europe and then spreading to the east.
Research has been done both in Russia and abroad to
try to explain the role of the wolf in the spread of invasive or
helminithic (I.E. caused by worms) diseases. In the Soviet Union
alone the wolf can be infected with more than 50 types of
parasites. Among these are several dangerous ones which can be
transmitted to farm animals and to people. Significant damage can
be done to wild hooved animals by larval parasites such as
echinococcia, cysticercocci, and coenuri, all of which can attack man
also. According to data from the Lenningrad Oblast' during a
serious flare-up of cysticercosis not one observed female moose give
birth to two calves, whereas in the Murmansk Oblast' where the outbreak
was three times less severe all the moose females had two calves.
The same type of situation was noted by Kheruvimov in 1969 in the
Tambov Oblast'. There are also reports of the deaths of female
moose and female deer caused by echinococcossi and cysticecocci.
Wolves in the wild, seriously infected with the adult stage of
cysticercosos by a tapeworm of the taenia family, are the sources of
this parasitic invasion. It has been noted that where there
aren't any wolves, the number of cysticerosis infected wild hooved
animals is much less (Peterson, 1955). According to our data
those wolves seriously infected with tapeworms (the source of larval
parasites in feral hooved animals and in man) are found where their
main food supply is hooved animals. In the Nenets Autonomous
Region (Nazarov, Belaev, 1975) all observed wolves were seriously
infected with tapeworms and four out of five had widespread
echinoccocci. In the Belovezhsk Forest from 1957 to 1962 all
eight wolves who underwent autopsies were found to be infected with
tapeworm types of parasites harmful to both animals and people.
Together with the sufficiently negative influence of
the wolf on its biocenosis by means of its spreading of infectious
diseases to both animals and people, there are also not so rare data
pointing out the elimination by the wolf-predator of sickly prey.
In all likelihood, such sickly prey are the source of the diseases for
healthy animals who get infected through the actions of the wolf.
Most likely, both sides have a point in this matter. However, up
to now neither side has evaluated the problem from an economic point of
view. Moreover, in the report on the wolf (Dr. Mech) the
culling-out role of the wolf was strongly emphasized, whereas its
negative influence on nature as a spreader of disease was not discussed.
What's been said here leads us to the conclusion
that deeper research on the wolf's epizootic role in the ecosystem is
necessary, research which is free from pre-conceived notions (common in
the past) and based on modern methodology.
That there is a need for stringent regulation of the wolf population in the USSR there can be no doubt.
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