Interpreting the physical evidence of predation on domestic livestock

Martin B. Main, Ph.D. Wildlife Ecologist
SWFREC, University of Florida-IFAS

There are numerous causes of animal deaths, including parasites, disease, poisonous plants, starvation, exposure to severe weather, ingestion of metal objects that penetrate the digestive tract, bloat, suffocation, lightning, and snake bites. Many predators will scavenge carcasses. Therefore, evidence of predators feeding on the carcasses of livestock does not serve as proof of predation.

In general, livestock killed by predators will exhibit subcutaneous bruising and puncture wounds. With larger calves and sheep there may be evidence of a struggle, such as trampled and bloody vegetation. Individual species of predators often follow a general pattern of killing animals that helps to identify the culprit. However, some individuals within a species vary in the method of attack and feeding behavior. These behaviors may overlap between individuals of different species; thus other evidence, such as tracks and feces in the area of the carcass, are often essential to correctly identify the predator responsible.

Predation on livestock in south and central Florida is most likely to occur from coyotes and domestic dogs, and with losses from bears, eagles, and bobcats much less likely. Although western cougars occasionally prey upon livestock, the endangered Florida Panther is so rare that losses of livestock to this predator are highly unlikely.

Coyotes

• Bite marks and subcutaneous bruising under neck and throat, bloody foam in the trachea
• Attacks to sides and hindquarters
• Canine puncture spacing: upper canines = 11/8–13/8 in., lower canines = 1–1¼ in.
• Often bite and consume nose, particularly on very young animals
• Feeding: usually begin on flank just behind the ribs, consuming organs and entrails

Domestic Dogs

• Indiscriminate mutilation of prey, bites on multiple areas of body
• Note: Some dogs become efficient predators and attack prey in a fashion similar to coyotes, and some coyotes attack prey in an indiscriminate fashion similar to dog attacks
• Often do not feed on prey, or consume very little

Black Bears

• Often kill with crushing bites to spine, skull, and dorsal side of neck
• Often kill more than 1 animal
• Claw marks often found on the neck, back, and shoulders of larger prey
• Usually consume the udder and flank
• Usually removes the paunch and intestines intact, and moves aside
• Often "skins out" the carcass and leave the hide intact
• Carcass often almost entirely eaten
• Prey often dragged to cover, prey sometimes covered with grass and dirt

Bobcats

• Usually kill small lambs by biting on the head or back of neck
• Often leaps on the back and bites the neck and throat of larger prey
• Hemorrhaging from claw punctures often can be found below the skin on the neck, back, sides, and shoulders
• Paired upper and lower canines usually are ¾-1 in. apart
• Often begin feeding on the viscera after entering behind the ribs
• Often drag and cover kills

Eagles

• Talon punctures in head and body
• Hallux (opposing talon) punctures are 4 – 6 inches from the middle toe wound
• Internal hemorrhage from talons
• Wool scattered (tufts of hair, wool) and carcass often "skinned out"
• Consumes entrails, organs, sometimes opens skull and eats brains
• Ribs removed near the spine on young animals
• Presence of white-streak feces

Panther/Cougar

• Usually bite to the back of the neck and skull causing massive hemorrhaging
• Large canine tooth punctures, upper canines 1¾-2 in. apart, lower canines 1–1¾ in. apart
• Large claw marks on head, neck, shoulder, flank
• Usually eviscerates the carcass, remove entrails and move aside
• Consume lungs, heart, liver, and larger leg muscles
• May drag and cover kills

Other, non-predator causes of mortality

• Mostly livestock die from other causes (poison plants)
• Look for foaming at nostrils & mouth (poison)
• Stillborn Animals
• Hooves covered with membrane (this membrane quickly wears off with activity)
• Lungs red and not inflated

Coyotes are territorial and will defend their hunting areas from other coyotes. Killing livestock is not a universal pattern among coyotes. If you are not experiencing loss of livestock to coyotes, removal of one or both of a territorial pair may result in the establishment of coyotes that have learned to prey on livestock. Consequently, removal of non-problem coyotes may be counter-productive.

If coyote control is warranted, the following information needs to be considered. Coyotes have no status as a game animal in Florida and can be shot during daylight hours, captured in live traps, or taken with body snares throughout the year. Permits from the Florida Game and Fresh Water Fish Commission (GFC) are required to shoot coyotes at night under spotlight. Permits also are required to use steel leg-hold traps or poison and may be obtained only by authorization of the Executive Director, as described under Rule 39-12.009, Provision 3: Killing Destructive Birds and Mammals. Applications for permits to control coyotes may be obtained by contacting your Regional GFC Law Enforcement Department, telephone numbers and addresses are provided.

Material used in this handout were synthesized from various sources, including a workshop on identifying livestock and big game depredation held at the 1997 meeting of The Wildlife Society and from a web site prepared by Texas A&M University (http://texnat.tamu.edu/ranchref/predator). Information on controlling coyotes was provided by Nick Wiley, Chief, Bureau of Wildlife Management, Florida Game and Fresh Water Fish Commission.

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