SEPTEMBER 20, 2018
Wildlife Services is a secretive taxpayer-supported
federal agency whose prime purpose is to kill
wildlife.
It uses a host of cruel methods to kill coyotes,
including trapping, poison, hunting, aerial gunning
and snares, all based on the flawed assumption that
such procedures will reduce coyote predation on
livestock, as well as huntable species like deer.
Ironically, such control measures increase the
likelihood of predation.
A breeding pair of coyotes will stake out and
defend a territory. If unmolested, a breeding
pair will have pups and form a pack of up
to 10 individuals. Each pack has a dominant
breeding pair. Other adults are behaviorally
“sterile” and do not breed.
To be successful at reducing coyote
populations, a minimum of 70 percent of
the population must be killed on a
sustained basis. That is almost never
achieved, and a vacant territory is quickly
filled by floating individuals, or by a nearby
pack.
Exploited coyote populations also have fewer adults
in a pack to feed pups, thus are more likely to attack
the easier prey available—which often is domestic
animals.
Overall, it seems Wildlife Service’s hundred years of
efforts in killing coyotes has not been effective. In fact,
it seems to the contrary. Coyotes have gone to being
a medium sized predator in the Western United
States to occupying all of North America.
Dr. Crabtree wrote “Prior to widespread human
persecution starting in the mid-nineteenth century,
wolves have provided a constant selection factor
inflicting mortality, competition, and numerous
other sub-lethal effects.” He then said this tremendous
pressure on coyotes from wolves resulted in the
evolution of a species that is in a nearly constant
state of colonization to make up for mortality and
displacement by wolves. When the wolves were
eliminated, the coyote’s drive to colonize did not end.
Crabtree concluded, “Coyotes are still products of their
evolutionary past. Biological, economical, and
ecological evaluation of control practices should be a
requirement undertaken before any public or private
effort to reduce losses due to coyotes or any other
predator. In conclusion, it is my opinion based on
decades of field research that the common practice
of reducing adult coyote populations on western
rangelands is most likely ineffective and likely
causes an increase the number of lambs, fawns,
and calves killed by coyotes.”
Double-litters in Coywolf,
Canis latrans × lycaon, Packs
Following the Death or
Disappearance of a Resident
Territorial Male
JONATHAN G. WAY Eastern Coyote Research,
89 Ebenezer Road, Osterville Massachusetts 02655 USA;
e-mail: jw9802@yahoo.com. Way, Jonathan G. 2010.
Previous research on my Cape Cod,
Massachusetts study site documented
the killing of a breeding male Coywolf
(Canis latrans x lycaon; also called
Eastern Coyote) and a subsequent
increase in local pack density one
year later. This study documents
double-litters produced in two packs
following the death or disappearance
of the original breeding male
The fact that the new males were not
resident in those territories until the
original males disappeared raises the
possibility that the disappearance of
the original breeding males allowed the
unrelated males to join the resident pack
and breed more than one female because
they both were probably not related to
either female in the respective packs.
Circumstances prevented my verifying
litter survival in these packs, increase
in density of either pack, increase in
transients (i.e., dispersal of the pups),
or decrease in territory size
(Way et al. 2009), which
distracts
from these findings.
However, I did document four
adults/ yearlings (i.e., a normal
pack size) in both groups
during winter.
Therefore, the possibility
remains that most pups in
the double litters died or
dispersed in their first autumn.
Despite not documenting
litter survival or increase
in local Coywolf density,
it is nonetheless noteworthy
that two double-litters were
documented following the
turnover of breeding males.
This indicates the potential
for densities of
Coyotes/Coywolves to
increase following loss
of breeding males
(Way et al. 2009).
Coyote Killing is
Counter Productive
In June, four environmental groups prevailed in a
lawsuit against the euphemistically named federal
killing agency known as Wildlife Services. The
U.S. District Court for Idaho ruled that Wildlife
Services had not adequately studied the impacts
on wildlife of its predator-killing activities in
the state. The court is formulating a remedy.
lawsuit against the euphemistically named federal
killing agency known as Wildlife Services. The
U.S. District Court for Idaho ruled that Wildlife
Services had not adequately studied the impacts
on wildlife of its predator-killing activities in
the state. The court is formulating a remedy.
The plaintiffs asserted that Wildlife Services’
lethal control of coyotes and hunters) is based
upon political expediency, not sound science.
lethal control of coyotes and hunters) is based
upon political expediency, not sound science.
A litany of scientific studies demonstrates that
lethal methods are ineffective at controlling
coyotes because they disrupt the animals’
social ecology and ultimately fail to reduce
predation losses.
lethal methods are ineffective at controlling
coyotes because they disrupt the animals’
social ecology and ultimately fail to reduce
predation losses.
Wildlife Services is a secretive taxpayer-supported
federal agency whose prime purpose is to kill
wildlife.
It uses a host of cruel methods to kill coyotes,
including trapping, poison, hunting, aerial gunning
and snares, all based on the flawed assumption that
such procedures will reduce coyote predation on
livestock, as well as huntable species like deer.
Ironically, such control measures increase the
likelihood of predation.
In a sense, Wildlife Services control begets
more coyotes and more predation, thus creating
a circular feedback mechanism that creates
political support for continued agency funding.
In other words, Wildlife Services does not
want to see coyote predation reduced since
the more predation it can create by its activities,
the more funding support it receives.
more coyotes and more predation, thus creating
a circular feedback mechanism that creates
political support for continued agency funding.
In other words, Wildlife Services does not
want to see coyote predation reduced since
the more predation it can create by its activities,
the more funding support it receives.
The basic issue is that Wildlife Services ignores
coyote social ecology.
coyote social ecology.
A breeding pair of coyotes will stake out and
defend a territory. If unmolested, a breeding
pair will have pups and form a pack of up
to 10 individuals. Each pack has a dominant
breeding pair. Other adults are behaviorally
“sterile” and do not breed.
This has implications for coyote control,
because in areas with heavy coyote mortality,
these typically “sterile” females are released
and can breed.
because in areas with heavy coyote mortality,
these typically “sterile” females are released
and can breed.
In addition to pack members, there are
always random individuals known as floaters,
which usually do not maintain a territory
but are available to breed if the dominant
breeders are killed. These floaters form a
reservoir of replacement breeders should a
breeding coyote be killed.
always random individuals known as floaters,
which usually do not maintain a territory
but are available to breed if the dominant
breeders are killed. These floaters form a
reservoir of replacement breeders should a
breeding coyote be killed.
In addition to these behavioral controls on
breeding, in unexploited coyote populations
that are near the saturation point in terms
of food availability, many pups die of
starvation and never reach maturity.
In exploited populations, a greater
number of pups will survive into
adulthood, often negating any losses
from Wildlife Services’ control efforts.
breeding, in unexploited coyote populations
that are near the saturation point in terms
of food availability, many pups die of
starvation and never reach maturity.
In exploited populations, a greater
number of pups will survive into
adulthood, often negating any losses
from Wildlife Services’ control efforts.
A further limit on coyote livestock
predation is due to learned behavior.
Coyotes, like most predators, are
reluctant to sample “new” food. If
they are not preying upon livestock,
they are unlikely to begin. However,
in exploited populations, young
orphaned coyotes must fend for
themselves and in desperation will prey
upon livestock and become livestock
killers.
predation is due to learned behavior.
Coyotes, like most predators, are
reluctant to sample “new” food. If
they are not preying upon livestock,
they are unlikely to begin. However,
in exploited populations, young
orphaned coyotes must fend for
themselves and in desperation will prey
upon livestock and become livestock
killers.
To be successful at reducing coyote
populations, a minimum of 70 percent of
the population must be killed on a
sustained basis. That is almost never
achieved, and a vacant territory is quickly
filled by floating individuals, or by a nearby
pack.
Furthermore, due to extreme competition
for food and territories, there are
compensatory mechanisms that quickly
repopulate any vacant space.
for food and territories, there are
compensatory mechanisms that quickly
repopulate any vacant space.
First, more females breed. Second, due to
reduced competition for food, a greater
percentage of pups survive and mature
into adults. Finally, in exploited
populations, female coyotes breed at a
younger age. All those mechanisms
ensure that coyote numbers seldom
decline for any significant period.
reduced competition for food, a greater
percentage of pups survive and mature
into adults. Finally, in exploited
populations, female coyotes breed at a
younger age. All those mechanisms
ensure that coyote numbers seldom
decline for any significant period.
Livestock grazing can also lead to more
coyote predation by reducing cover for the
preferred prey of mice and voles, which results
in lower small-mammal populations.
coyote predation by reducing cover for the
preferred prey of mice and voles, which results
in lower small-mammal populations.
Exploited coyote populations also have fewer adults
in a pack to feed pups, thus are more likely to attack
the easier prey available—which often is domestic
animals.
In the end, the only alternative that is effective is
nonlethal measures such as guard animals,
corralling livestock at night and herding.
Indeed, in some California counties, tax dollars
that previously went to Wildlife Services were
used for nonlethal methods, resulting in lower
predation losses and lower costs.
nonlethal measures such as guard animals,
corralling livestock at night and herding.
Indeed, in some California counties, tax dollars
that previously went to Wildlife Services were
used for nonlethal methods, resulting in lower
predation losses and lower costs.
It’s time to put the Wildlife Services killing
machine out of business, and to put more
responsibility upon ranchers to manage
their animals in a way that reduces
predator opportunity.
machine out of business, and to put more
responsibility upon ranchers to manage
their animals in a way that reduces
predator opportunity.
Ecologist George Wuerthner has published
36 books including Wildfire: A Century of
Failed Forest Policy. He serves on the
board of the Western Watersheds Project.
36 books including Wildfire: A Century of
Failed Forest Policy. He serves on the
board of the Western Watersheds Project.
------------------------------------------------------------------------
Famous scientist tells USDA
Wildlife Services their age old
coyote killing program
actually increases number
of coyotes and depredations-
USDA Wildlife Services and its prior incarnations
such as Animal Damage Control and Predator
and Rodent Control has been indiscriminately
killing coyotes for as long as the agency existed.
This practice has often irritated a diffuse
collection of conservationists, scientists,
and the general public. However, politically
better placed livestock interests have been
able to keep the program going year after year.
such as Animal Damage Control and Predator
and Rodent Control has been indiscriminately
killing coyotes for as long as the agency existed.
This practice has often irritated a diffuse
collection of conservationists, scientists,
and the general public. However, politically
better placed livestock interests have been
able to keep the program going year after year.
Overall, it seems Wildlife Service’s hundred years of
efforts in killing coyotes has not been effective. In fact,
it seems to the contrary. Coyotes have gone to being
a medium sized predator in the Western United
States to occupying all of North America.
Indiscriminate killing, as opposed to targeted control,
refers to killing as many coyotes as possible in an
area, given the resources available. Targeted
control is the effort to kill or otherwise deter
specific coyotes that are preying on livestock
(usually sheep).
refers to killing as many coyotes as possible in an
area, given the resources available. Targeted
control is the effort to kill or otherwise deter
specific coyotes that are preying on livestock
(usually sheep).
In a letter to Wildlife Services, Dr. Robert
Crabtree, founder, chief scientist and president
of the Yellowstone Ecological Research Center, http://www.yellowstoneresearch.org
answers the question “What effect does
reduction of coyotes (older than 6 months)
have on the remaining population?”
He wrote the scientific opinion letter because
of a request from Brooks Fahy, Executive
Director of Predator Defense.
Crabtree, founder, chief scientist and president
of the Yellowstone Ecological Research Center, http://www.yellowstoneresearch.org
answers the question “What effect does
reduction of coyotes (older than 6 months)
have on the remaining population?”
He wrote the scientific opinion letter because
of a request from Brooks Fahy, Executive
Director of Predator Defense.
Dr. Crabtree wrote “Prior to widespread human
persecution starting in the mid-nineteenth century,
wolves have provided a constant selection factor
inflicting mortality, competition, and numerous
other sub-lethal effects.” He then said this tremendous
pressure on coyotes from wolves resulted in the
evolution of a species that is in a nearly constant
state of colonization to make up for mortality and
displacement by wolves. When the wolves were
eliminated, the coyote’s drive to colonize did not end.
Human attempts to reduce or eliminate coyotes
were actually relative mild compared to the previous
presence of wolves. Coyote populations often
expanded to “near saturation” of the available
habitat. Whenever coyotes were killed
indiscriminately in large numbers in an area,
there was immediate immigration. Also,
while “unexploited” coyote populations had
low pup survival rates, with human caused
mortality (“exploited populations”) coupled
with no wolves, coyote pup survival increased
greatly due to a prey surplus. As the unusual
number of surviving pups grew, there was
pressure for hunting coyotes to overcome
caution and attack more concentrated sources
of calories, i.e., sheep and deer, rather than
voles, rabbits, insects, etc.
were actually relative mild compared to the previous
presence of wolves. Coyote populations often
expanded to “near saturation” of the available
habitat. Whenever coyotes were killed
indiscriminately in large numbers in an area,
there was immediate immigration. Also,
while “unexploited” coyote populations had
low pup survival rates, with human caused
mortality (“exploited populations”) coupled
with no wolves, coyote pup survival increased
greatly due to a prey surplus. As the unusual
number of surviving pups grew, there was
pressure for hunting coyotes to overcome
caution and attack more concentrated sources
of calories, i.e., sheep and deer, rather than
voles, rabbits, insects, etc.
Crabtree said that in order for humans to
reduce coyote populations, there needed
to be 70% or greater coyote mortality. This
was not just for a year, but all of the time.
Significant indiscriminate reductions of
coyotes triggers a switchover of the coyote
population back to one of constant colonization.
reduce coyote populations, there needed
to be 70% or greater coyote mortality. This
was not just for a year, but all of the time.
Significant indiscriminate reductions of
coyotes triggers a switchover of the coyote
population back to one of constant colonization.
Crabtree concluded, “Coyotes are still products of their
evolutionary past. Biological, economical, and
ecological evaluation of control practices should be a
requirement undertaken before any public or private
effort to reduce losses due to coyotes or any other
predator. In conclusion, it is my opinion based on
decades of field research that the common practice
of reducing adult coyote populations on western
rangelands is most likely ineffective and likely
causes an increase the number of lambs, fawns,
and calves killed by coyotes.”
Here is Dr. Crabtree’s full letter.
---------------------------------------------------------------
Double-litters in Coywolf,
Canis latrans × lycaon, Packs
Following the Death or
Disappearance of a Resident
Territorial Male
JONATHAN G. WAY Eastern Coyote Research,
89 Ebenezer Road, Osterville Massachusetts 02655 USA;
e-mail: jw9802@yahoo.com. Way, Jonathan G. 2010.
Previous research on my Cape Cod,
Massachusetts study site documented
the killing of a breeding male Coywolf
(Canis latrans x lycaon; also called
Eastern Coyote) and a subsequent
increase in local pack density one
year later. This study documents
double-litters produced in two packs
following the death or disappearance
of the original breeding male
The fact that the new males were not
resident in those territories until the
original males disappeared raises the
possibility that the disappearance of
the original breeding males allowed the
unrelated males to join the resident pack
and breed more than one female because
they both were probably not related to
either female in the respective packs.
Circumstances prevented my verifying
litter survival in these packs, increase
in density of either pack, increase in
transients (i.e., dispersal of the pups),
or decrease in territory size
(Way et al. 2009), which
distracts
from these findings.
However, I did document four
adults/ yearlings (i.e., a normal
pack size) in both groups
during winter.
Therefore, the possibility
remains that most pups in
the double litters died or
dispersed in their first autumn.
Despite not documenting
litter survival or increase
in local Coywolf density,
it is nonetheless noteworthy
that two double-litters were
documented following the
turnover of breeding males.
This indicates the potential
for densities of
Coyotes/Coywolves to
increase following loss
of breeding males
(Way et al. 2009).
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