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DAMAGE IDENTIFICATION |
Procedures for Evaluating Predation on
Livestock and Wildlife |
Carnivore predation on
other species is a natural event that occurs throughout
their range. In some cases, it may provide an essential
part of control for some wildlife populations; however,
it may be harmful to other wildlife populations and is
detrimental to livestock production. In addition to
livestock, native and exotic wildlife are lost to
predators on both public and private lands, including
game ranches and preserves. In determining the cause of
these losses, the general criteria used to evaluate
predation on livestock may be applied to other species.
Evidence of predation is
normally present where large animals are killed but is
frequently absent with small animals which may simply
disappear without a trace. The presence of predators and
predator sign in the area, in addition to hair, feathers
and other remains in predator droppings (feces), even
when simultaneous with livestock disappearance, are not
sufficient evidence to confirm predation. Predators
often scavenge animals dead of other causes and
livestock can disappear in other ways.
Animal losses are easiest
to confirm and evaluate if examination is conducted soon
after losses occur. Examination of wounded animals and
fresh kills is relatively simple. Carcass decomposition,
which is rapid during warm weather, obliterates
evidence. Scavenging birds and mammals also can
eliminate evidence, frequently in a few hours.
In separating predation
from other mortality factors, the following information
may be required:
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Predator species
present in the area
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Habits and signs of
each predator species
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History of depredation
problems in the area
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Normal and abnormal
livestock appearance and behavior
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Common causes of
livestock losses other than predators:
a. Starvation and/or exposure
b. Internal parasites
c. Bacterial and viral diseases
d. Pregnancy disease and other metabolic diseases
e. "Hardware" disease caused by ingestion of nails,
wire or other metal objects which penetrate walls
of the digestive tract
f. Bloat
g. Suffocation
h. Poisonous plants and moldy feeds
i. Other poison sources such as chemicals and
lead-based paints, or discarded batteries
j. Lightning
k. Snake bite
l. Theft
In some instances, the
causes of death are obvious; however, in many cases they
may be obscure. When the cause of livestock loss cannot
be readily determined, assistance may be necessary.
Veterinarians can identify and treat internal parasites
and other diseases which kill livestock. Where poisonous
plants cause loss, county Extension agents and range
specialists can help identify these plants and devise
corrective management procedures. Poisoned animals may
require treatment by a veterinarian.
Animal Health
Careful observation of
livestock and range conditions can provide information
useful in preventing death; thus, indications of ill
health in live animals may aid diagnosis when dead
animals are found. When the cause of loss is unknown or
uncertain, a veterinarian's assistance in diagnosing the
cause of death may help prevent further losses.
Diagnostic laboratories may help determine the cause of
death; these facilities are available in all states.
Some animal diseases can be transmitted to humans and
proper precautions always should be taken to prevent
exposure during carcass and tissue sample examination.
External Appearance of
Animal and Carcasses
Although hair or fleece length and density varies
with livestock breeds, healthy animals normally have a
coat that is glossy from natural oils and is "live" to
the touch; their skin is soft and flexible. In contrast,
unhealthy animals have dry, dull coats that are harsh to
the touch. Extended periods of poor health cause their
skin to become dry and less flexible.
Coat condition is more
difficult to evaluate in sheep since there is wide
variation in fleece length, diameter and density in
different breeds. There is also great variation,
resulting from diet and nutrition, in the amount of
natural oils in the fleece. Range type, vegetation and
weather conditions also can cause marked differences in
wool color and appearance. For example, extended wet
periods, particularly in forested areas, cause fleece
darkening. Also, unshorn sheep in late spring and summer
may have a ragged appearance from some wool loss,
particularly where they range in brush and lose wool on
snags.
An alert appearance of the
eyes and ears of livestock normally indicates a healthy
animal. Sunken eyes and drooping ears indicate poor
health. In fresh carcasses of healthy animals, the eyes
fill the sockets and are not sunken from dehydration;
however, carcasses dehydrate and decompose rapidly in
temperatures above freezing.
Normally, livestock feces
are relatively firm and dry. Exceptions include young
animals receiving large amounts of milk and adult
animals on lush, green forage. High quantities of
concentrates also will cause soft feces. This should not
be confused with diarrhea, an unhealthy condition
resulting from excessive quantities of concentrates,
certain infectious diseases or diseases caused by
internal parasites.
Animals that die from
causes other than predation normally die on their side
or chest with their legs folded under them. Animals
which get on their backs and die of suffocation are one
major exception. This occurs most often in sheep
attempting to scratch by rolling on their backs. Those
with long, dense fleece may be unable to right
themselves. In this position, gas cannot escape from the
rumen, which distends and compresses the lungs, causing
suffocation.
Another common cause of
death is gas distention of the rumen (bloat) which may
be caused by ingesting excessive amounts of grain or by
feeding on alfalfa, clover and certain other plants.
Bloat should not be confused with excessive carcass
distention caused by gasses formed during decomposition.
Carcasses should be
examined for abnormal excretions, particularly pus or
blood, from body openings (the eyes, ears, mouth,
genitals and anus). Live animals and carcasses should be
examined by a veterinarian if such abnormalities exist
or are suspected.
The carcass should be
examined for skull fractures, broken bones and other
wounds. The chest and stomach cavities should be opened
to check for internal injuries and hemorrhage.
Internal Carcass
Appearance
Body Fat
Animals receiving adequate nutrition normally have
deposits of white or yellow fat around the kidneys,
heart and intestines and in the bone marrow. Animals
that are sick or are receiving insufficient feed
normally metabolize this fat to meet body needs, leaving
a gelatinous red deposit in the bone marrow. Internal
fat is metabolized first while fat in the bone marrow is
metabolized last during starvation. Breaking the large
leg bones permits examination of the bone marrow. Some
caution is necessary in evaluating bone marrow fat
deposits in healthy young animals making rapid growth.
Their bone marrow may be red from extensive red blood
cell production to meet body needs and may have little
stored fat.
Intestinal Tract
The contents of the stomach and intestines are
indicators of health. Normally, healthy ruminants
(cattle, sheep, goats and other animals with multiple
stomachs) older than weaning age will have a rumen
(first compartment) that is one-third to one-half full
of food. The rumen is not fully developed at birth, but
the abomasum (fourth compartment) is fully functional.
The abomasum is the functional stomach in nursing young
and should contain milk. A small, empty rumen is normal
in nursing young for the first 2 to 3 weeks. A mixture
of milk and vegetation in the rumen is normal from then
until weaning age when the rumen is fully functional.
Partially digested foods should be present through the
rest of the gut and the feces (in the large intestine)
should be relatively firm. Exceptions as noted earlier
include animals on concentrates and lush green feeds.
When dietary contents such
as excessive amounts of grain or poisonous plants are a
possible cause of death, the contents of the stomach and
intestines should be noted. Samples of the stomach
contents should be taken for analysis if poisonous
plants or other toxic agents are suspected.
Lungs and Respiratory
Tract
Pneumonia is a relatively common cause of animal
death and is evident in lung tissue by fluid
accumulation and other lesions in the affected areas.
Healthy lungs are pink, spongy and lightweight with
sharp, well defined edges on the lobes. Infected lung
tissue is dark colored, firmer and heavier than healthy
lung tissue. Some diseases cause abscesses in lung
tissue. These abscesses may be filled with pus and often
have a hard outer shell. Incisions through sections of
normal and infected lung tissue will demonstrate these
differences.
The trachea and bronchi should be opened from above the
larynx into the lungs to check for infection and other
abnormalities. Animals killed by a bite in the throat
frequently have physical injury to the larynx and
trachea. Also, these bites frequently cause hemorrhage
and foam in the trachea which contribute to death by
suffocation.
Animal Age and Health
Very old and very young
animals are less likely than healthy adults to survive
poor nutrition, adverse weather and exposure, and they
are generally more susceptible to disease. Therefore,
age and apparent health of animals prior to death should
be considered in evaluating losses.
Young animals,
particularly newborn pigs, lambs and kids are extremely
vulnerable to exposure during cold, wet weather. If they
do not receive adequate maternal care and do not nurse
within the first few hours they are not likely to
survive. Birth weight also is important to survival;
newborn young that are small and weak are less likely to
survive than healthy, vigorous young of average or
larger size.
Diseases of pregnancy and
difficult births may cause the death of either or both
the mother and fetus. Necropsy (examination and
dissection of a body after death) of females in
parturition should include attention to pregnancy
diseases and to injuries sustained in giving birth, in
addition to unusually large fetuses and those in
abnormal positions. Post-mortem examination of newborn
and very young animals should include attention to the
major characteristics of healthy young, such as: 1)
Young born alive will have a distinct blood clot at the
closed end of the navel (umbilical artery); stillborn
young will not have this clot. 2) If young animals
breathe after birth, the lungs inflate, become light
pink and will float in water (complete lung inflation
may require several hours); stillborn young have
uninflated, dark, red-purple lungs which do not float.
3) Firm, white fat deposits around the heart and kidneys
indicate health; the lack of this fat indicates poor
nutrition or starvation. As young healthy animals grow,
they also develop fat deposits in tissues around the
stomach and intestines (mesenteric fat). 4) Milk is
normally present in the stomach and intestines of
healthy young. The absence of milk during the first few
weeks indicates poor nutrition; however, milk content of
the stomach decreases as the diet changes to solid foods
and weaning takes place. 5) Digestion of milk produces
chyle, a white emulsion of milk fat and lymph. This is
found in the lymphatic vessels which drain the
intestinal tract and is present immediately after young
animals suckle. 6) The soft membrane on the hooves of
newborn animals begins to wear as soon as the young
stand and begin walking. Hard, dry soil surfaces cause
more rapid wear than soft, wet surfaces.
Missing Livestock
It is not unusual for
livestock to disappear from pastures and herds and there
are numerous possible causes. Young or small animals
such as pigs, calves, lambs and kid goats frequently
disappear. However, when no trace of the animals can be
found, particularly when they have been well tended and
confined to pasture, predation or theft may be the
cause.
Livestock and their young
normally remain close enough that young animals can
nurse several times daily, particularly for the first
few weeks after birth. Therefore, a lactating female
with engorged udder, searching for her young for
prolonged periods may be evidence that the young is
missing or dead. This type of maternal behavior is less
likely to occur where females have one remaining of two
or more offspring. Because they behave differently and
have large litters, hogs are less likely to respond in
this fashion if several young remain.
Domestic animals are much
less wary and nervous than wild species, particularly
when they are herded or otherwise handled regularly.
Their customary behavior is modified by weather,
temperature, availability of feed and other factors.
However, the behavior pattern is characteristic for each
individual herd under a specific type of management.
Other livestock behavior
is useful as indirect evidence of predation. The
presence of carnivores which appear to exhibit a threat
usually will cause most cows to bawl and attempt to
locate their young. Their behavior will be alert, much
exaggerated from normal and will include urgent calling,
running to find their calves and attempts to chase the
carnivores. Sheep and goats respond in a similar manner
when alerted but they are much less aggressive than
cattle. They do call urgently and attempt to find their
young, but some may abandon their search and try to
escape to protect themselves.
Almost without exception,
the behavior of livestock in herds which are raided
repeatedly by predators becomes more alert and
defensive. They appear frightened even by common
management practices that do not normally disturb them,
especially when carnivore hunting behavior involves
chasing the herd while making a kill rather than by
stalking individual animals. Once established by
repeated depredation, this response continues and will
recur for days or weeks. With normal management, this
unusual behavior will gradually disappear if predation
stops. To the person versed in livestock production and
familiar with the individual herd, abnormal behavior is
readily apparent and indicates a reaction to an unusual
disturbance.
Evaluation of Suspected
Predator Kills
There is a logical,
scientific procedure for evaluating predator kills and
feeding to determine the species responsible, but there
is no simple series of steps which lead to consistent
and accurate determinations. Predators frequently feed
on carrion (dead animals) and take other predator kills.
Several species may feed on the same carcass. Much
experience and intuitive judgment may be essential for
successfully identifying the predator species
responsible.
A common error made in
evaluating predator kills and feeding is the tendency to
stereotype these by species. Most predators do follow a
general pattern, but individuals vary in food
preferences, method of attack and feeding behavior.
These behaviors may overlap extensively between
individuals of different species; consequently, evidence
other than the carcass is frequently essential to make
accurate judgments. The following procedure is suggested
for determining if a loss has resulted from predators
and for identifying the species.
Because humans are
susceptible to many diseases carried by animals, always
take proper precautions to prevent exposure during
examination of all animal carcasses.
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Examine injured
animals for the type and extent of wounds and
feeding. If possible, determine whether wounds were
made by mammals (canine teeth and/or claws), by
birds (talons and/or beaks), or by other causes.
Some animals are fed upon without being killed.
Coyotes may bite off the tails and feed on the
hindquarters of live calves. They may feed on calves
and on the genitals and hindquarters of cows giving
birth. Black bears and coyotes occasionally feed on
the udders of lactating females without killing
them. At times, raccoons also feed on young or
defenseless livestock without killing them,
Similarly, vultures, magpies, ravens and gulls may
attack and feed on young or defenseless livestock,
peck out their eyes and kill them. Newborn young,
females giving birth and other helpless animals are
especially vulnerable.
Dogs often cause extensive injuries to young and
small livestock without killing them, but do not
usually feed on them. Some dogs learn to kill
efficiently and feed like coyotes normally do.
Injuries caused by coyotes sometimes resemble those
caused by dogs. This may be a result of inexperience
in killing, two or more coyotes attacking the same
animal or a heavy fleece which prevents effective
attack at the throat. Other factors, such as
physical injuries which restrict coyotes from their
normal attack, also affect killing behavior of
individual coyotes. A high percentage of animals
injured in such attacks die later from shock, loss
of blood or infections.
Such wounds and feeding patterns confirm predation
but injuries do result from other causes such as
thorns, nails, barbed wire and vehicles. Venomous
snake bites cause injuries which may be difficult to
identify without careful examination.
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Where predation is
suspected or confirmed, locate the attack, kill and
feeding sites if possible. Avoid tracking over and
destroying evidence such as tracks and droppings
around these sites and the carcass. Since feeding
and other predator sign may be similar, it is often
essential to have all available evidence to confirm
the cause of death and/or the species responsible.
Many predators move their kills. Small animals are
frequently carried away by foxes, bobcats and
coyotes. Cougars, bobcats and black bears seem to
prefer feeding in a secluded area and they may drag
or carry their kills to cover. All three species
normally feed in a limited area without scattering
carcass remains and they frequently cover carcasses
with dirt, grass, leaves or other debris. In
contrast, coyotes that feed extensively tend to
scatter carcass remains, wool and hair over much
larger areas while feeding.
Predator sign is frequently found near kill sites.
Trails, fencelines, creeks, waterholes and dry
washes in the vicinity should be checked for tracks
and droppings. Crawls through or under net wire
fences are quite common and hair is often found on
the soil or clinging to wire where predators pass
through or under these fences.
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Examine carcasses for
wounds, hemorrhage, bruises, broken bones and
feeding. If necessary, the entire carcass should be
skinned and opened to identify internal wounds and
other factors which help confirm the cause of death.
For example, some animals are killed by a single
grip at the throat which causes suffocation but
leaves little external evidence. Bears and cougars
may kill by blows from the front paws that break the
neck or back and may cause extensive bruises but
these may not be apparent prior to necropsy. Claw
marks caused by cougars and bobcats may be much more
evident on the flesh side of the skin because of
dense hair or wool.
Be careful not to confuse bruises, which are
localized and a dark color from clotted blood, with
the conditions caused by decomposition. At certain
stages, decomposition may resemble extensive
bruises. Also, body fluids collect on the lower side
of the carcass during decomposition and cause
extensive areas of discoloration. Discoloration
caused by snakebite may also be obscured by
decomposition; careful and complete examination may
be necessary to find these wounds.
The position of the carcass may be important.
Animals that are killed are rarely found lying in a
natural position. Also, scavengers may move or turn
a carcass over while feeding. As a result, caution
is necessary in attempting to reconstruct the
circumstances of death since postmortem changes
which developed with the body in one position may
cause judgment errors when its position has been
changed.
General Characteristics
of Predator Kills
The number, size, depth
and location of tooth or talon punctures vary. Some
animals are killed by a single bite at the throat or
neck. Small animals are often killed by a bite over the
head, neck, shoulders or back. Since most predators find
large animals harder to kill than small prey, they may
bite repeatedly while shifting their grip to subdue prey
animals.
In contrast, when prey is
relatively small compared to the predator, a single bite
is often sufficient to kill. As a rule, therefore, where
many tooth punctures accompanied by hemorrhage are
found, predators smaller than their prey are the most
probable cause of death. However, young, inexperienced
predators are also likely to inflict multiple injuries
by indiscriminate attacks without killing their prey.
This is relatively common with foxes, coyotes and dogs
and is particularly true of dogs.
Although size and spacing
between the canine teeth (responsible for most tooth
punctures) are characteristic for each species, tooth
punctures in tissue are often difficult to assign to a
species since there are close similarities in species of
similar size. Also, punctures do not remain clear and
distinct because of tissue pliancy and movement.
Differences are further obscured by multiple bites and
punctures; therefore, additional information may be
needed.
Foxes rarely crush the
skull or spine on small livestock prey, but such
injuries are relatively common on small lambs, goats and
pigs killed by coyotes, bobcats and larger carnivores.
Cougars and bears are capable of and frequently cause
similar massive injuries to adult sheep and goats,
calves and other animals of similar size with bites over
the head, neck or shoulders. Broken bones are more
commonly found when the predator is relatively large
compared to its prey.
Most predators tend to
attack the head and neck, although eagles may grasp
small prey anywhere. Eagles commonly leave talon wounds
in the shoulders, ribs and back, and often in the
brisket and abdomen of small animals such as lambs and
kid goats. They often grasp small prey by the head or
neck but the spacing between the talon wounds ( 1 to 3
inches between front talons, and 4 to 6 inches between
the middle front talon and the back talon or hallux),
the triangular shape, and the depth of the wounds (up to
2 inches) are different than canine tooth punctures.
Compression skull fractures of small prey, such as lambs
and kids, may result from the eagle's grip. Internal
bleeding is common in animals killed by eagles when
their talons have entered the abdominal or thoracic
cavities. Frequently, an eagle's talons puncture major
internal veins and arteries, particularly the dorsal
aorta, causing massive internal hemorrhage.
Bruises and extensive
shoulder and back injuries are frequent in bear attacks
on adult livestock but should not be confused with
bruises caused by other livestock. For example, sheep
may be injured by cattle and horses, particularly when
livestock concentrates at the same locations. Bears may
also claw and bruise the sides and abdomen while holding
their prey. Bears may leave claw marks on the head, neck
and shoulders, but these are more commonly found on
cougar and bobcat kills.
Hemorrhage from arteries
and veins differs. Arterial blood is normally bright red
while veinous blood is dark. Blood pressure is much
higher in arteries than in veins and arterial blood is
ejected in rapid spurts, often for several feet, as the
heart contracts. In contrast, veinous bleeding is steady
and much slower because of low pressure. Blood from
wounds or from the nose and mouth of injured animals is
thick and will readily clot. It is distinctly different
from the thin, reddish fluids resulting from
decomposition.
Observation of predators
making kills is relatively rare; therefore, when
predators are removed, there is the question of whether
the individual responsible predators or groups have been
removed, or whether those removed were simply
scavengers. Evidence that the responsible animals were
removed is usually indirect. Occasionally they are
observed in the act of killing or may be identified by
other information such as unique tracks, killing methods
or other definitive factors.
Knowledge that only
specific animals live in the area or travel into an area
to kill provides some evidence. More commonly, the
evidence depends on predation patterns and loss levels
that stop or are reduced when predators are removed.
Occasionally, a predator is shot while attacking or may
be trailed (by tracks or use of dogs) from a kill site
to assure its removal. Stomach contents can be examined
to determine if the captured predator has fed on a fresh
kill. This alone is not sufficient to confirm
responsibility for the kill but it suggests involvement.
Carnivore tracks and
territorial marks are characteristic for each species,
but they may be difficult to find. The characteristics
of tracks are most easily seen in mud, dust or snow but
often are not clear on other surfaces. Experience is
essential for accurate identification of predator
tracks, feces and other marks.
Procedures for
Evaluating Predation on Livestock and Wildlife
Illustrated Field Guide
There are individual
sections on predation organized by predator. A list of
these sections can be found under Illustrated Field
Guide on the
predation main page or from the links below. These
sections contain text describing and photos depicting
predation by that predator. They describe the principles
and procedures used to separate predator caused injuries
and mortalities in livestock and wildlife from those
resulting from other causes. Proper identification
demands recognition and evaluation of all available
evidence. Application of these principles will help the
investigator determine whether or not predation was
involved and frequently what predator species was
responsible.
Diseases, parasites, toxic
plants and other mortality factors may require diagnoses
by veterinarians and pathologists. In some instances,
the absence of food or the presence of toxic plant
materials in the digestive tract may provide definitive
evidence of the cause of death. In others, the presence
of parasites and symptoms of disease can be readily
diagnosed. Numerous references on these factors are
noted in the reference list for those who wish to review
these topics.
Knowledge and skill are
often necessary to determine the cause of injuries or
death. Although direct observation of predation is rare,
it is the most specific evidence possible and may also
permit identification of the responsible animal. Fresh
injuries or kills which exhibit tooth, claw or talon
punctures and hemorrhage are also specific evidence of
predation. However, it is seldom possible to identify
the individual predator responsible and occasionally it
is not possible to identify the species from the carcass
appearance alone.
In many instances,
determination of predation as the cause of death must be
made from circumstantial evidence where the carcasses
alone do not provide adequate evidence. The history of
predation in a specific area, aberrant livestock
behavior, young or small livestock that simply
disappear, predator sign (including tracks and droppings
containing bone fragments or hair of prey species) are
factors that provide circumstantial evidence. With
sufficient care and evaluation of indirect evidence, it
is often possible to rule out or to confirm predation as
a cause of death with a reasonable degree of certainty.
Elements Used to Identify
Predation
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Livestock behavior
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Direct
evidence
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Indirect evidence
Predator Species
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Coyotes
Coyotes are the most common and the most serious
predator of livestock in the western United States.
Westwide, they cause a majority of the predation
losses of sheep, goats and cattle. In some states,
this is also true for hogs and poultry. In attacks
on adult sheep and goats, coyotes typically bite the
throat just behind the jaw and below the ear,
although repeated bites made while shifting their
hold may obscure the initial tooth punctures. Death
commonly results from suffocation and shock; blood
loss is usually a secondary cause of death. On small
prey such as young lambs and kids, coyotes may kill
by biting the head, neck or back, causing massive
tissue and bone damage.
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Dogs
Domestic dogs can be a serious problem where they
are permitted to run at large, particularly near
urban areas. True feral dogs and coydogs (coyote-dog
hybrids) are also a problem but are far less common.
Domestic dogs do not normally kill for food and
their attacks usually lead to indiscriminate
mutilation of prey. When they do feed, they tend to
leave torn, ragged tissue and splintered bones much
like coyotes do.
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Foxes
Although poultry are their more common domestic
prey, both red and gray foxes may prey on livestock.
This is generally less typical of gray foxes.
Usually, foxes kill only young or small animals,
particularly lambs and kids. However, in some
circumstances, probably because their food is
limited, red foxes may kill large lambs and kids,
adult sheep and goats and small calves.
Foxes usually attack the throat of lambs and kids,
but kill some by multiple bites to the neck and
back. This may result from young animals being
caught while lying down.
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Bobcats
Bobcat hunting and killing behavior is much like
that of cougars because they prefer to stalk their
prey and attack from cover. On small prey, such as
lambs, kids and fawns, they bite into the skull or
back of the neck and may leave claw marks on the
back, sides and shoulders. Bobcats may also kill
with a bite in the throat, typically just back of
the jaws over the larynx. This could result from
catching the prey after it falls, or it may be
individual bobcat behavior.
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Cougars
Cougars attempt to stalk their prey and attack from
cover. They frequently kill sheep and goats by
biting the top of the neck or head. Broken necks are
common in these kills. This differs from the typical
coyote bite in the throat and general mutilation
caused by dogs. However, cougars also may kill sheep
and goats by biting the throat. This may result from
prey falling or being knocked down and caught, or it
may simply be the method found effective by
individual cougars and most convenient on some prey
animals.
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Black bear
Grizzly bears are common in parts of Canada and
Alaska but occur only in limited areas of the west
in the lower 48 United States, primarily in
Yellowstone Park and in northwestern Montana. They
are omnivores and consume large amounts of
vegetation and wild fruits in addition to carrion
and prey. Predation by black bears on livestock is
most common in spring and summer. Limited food
sources in early spring and failures of wild berry
and nut crops during summer months are probably
major contributing factors.
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Golden eagle
Both bald and golden eagles may prey on livestock,
but usually golden eagles, are responsible. Both
species readily accept livestock carrion and
carcasses of foxes and coyotes, although some
individuals may prefer live prey to carrion. Eagles
are efficient predators and they can cause severe
losses of young livestock, particularly where
concentrations of eagles exist. Generally, they prey
on young animals, primarily sheep and goats,
although they are capable of killing adults. Golden
eagles also take young deer and antelope, as well as
some adults.
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Raven
Vultures, ravens, crows, magpies and some gulls
commonly scavenge carcasses. In some circumstances,
they may attack live animals and kill those that are
unable to escape or defend themselves. Initial
attacks by these birds are usually at the eyes and
nose, navel and anal area. Typically, they blind the
animals by pecking out the eyes even if they do not
kill them.
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Gull
Vultures, ravens, crows, magpies and some gulls
commonly scavenge carcasses. In some circumstances,
they may attack live animals and kill those that are
unable to escape or defend themselves. Initial
attacks by these birds are usually at the eyes and
nose, navel and anal area. Typically, they blind the
animals by pecking out the eyes even if they do not
kill them.
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Hawk
Vultures, ravens, crows, magpies and some gulls
commonly scavenge carcasses. In some circumstances,
they may attack live animals and kill those that are
unable to escape or defend themselves. Initial
attacks by these birds are usually at the eyes and
nose, navel and anal area. Typically, they blind the
animals by pecking out the eyes even if they do not
kill them.
-
Vulture
Vultures, ravens, crows, magpies and some gulls
commonly scavenge carcasses. In some circumstances,
they may attack live animals and kill those that are
unable to escape or defend themselves. Initial
attacks by these birds are usually at the eyes and
nose, navel and anal area. Typically, they blind the
animals by pecking out the eyes even if they do not
kill them.
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Raccoon
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Hog
In some areas, domestic or wild hogs (Russian boar,
domestic hogs gone wild, and their crosses) prey on
poultry and livestock. This occurs more often during
droughts or other periods when mast (acorns, etc.)
and other foods are scarce. Hogs will also feed
readily on carrion but some hogs become highly
efficient predators. Hog predation on livestock
usually occurs on lambing or calving grounds,
perhaps partially because of the prevalence of
afterbirth. Occasionally, adult animals giving birth
are fed upon and killed by hogs.
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Rattlesnake
Venomous snakes, particularly rattlesnakes, occur on
nearly all livestock ranges of the southern and
western United States and in many other areas; thus,
it is inevitable that substantial numbers of
livestock are bitten. Because young animals (colts,
calves, lambs and kids) are curious and far less
cautious than adults, they are the most common
victims of snakebite in livestock. Many of them are
bitten on the nose or head as they attempt to
investigate snakes.
Special
thanks to:
Clemson University
Dale A. Wade and James E. Bowns, Texas Agricultural
Extension Service 111 Nagle Hall, Texas A & M
University, College Station, TX 77843 Phone (979)
845-6573 Refer to publication number: B1429
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