Scott E. Hygnstrom Extension Wildlife Damage Specialist Department of Forestry, Fisheries HAWKS AND OWLS and Wildlife University of Nebraska Fig. 1. Raptors, representative of those that may cause damage by preying on poultry and other Lincoln, Nebraska 68583-0819 birds, pets, and other animals: (a) the goshawk (Accipiter gentilis), (b) red-tailed hawk (Buteo Scott R. Craven jamaicensis), and (c) great horned owl (Bubo Extension Wildlife Specialist virginianus). Department of Wildlife Ecology University of Wisconsin, Madison Immature Madison, Wisconsin 53706 Adult Immature

Adult

b

c a

Damage Prevention and Install utility lines underground and Trapping and Relocating remove telephone poles near Control Methods State and federal permits are required poultry-rearing sites. to trap and relocate hawks and Exclusion Cap poles with sheet metal cones, owls. If possible, experienced bird Nixalite®, Cat Claws®, or inverted banders or trappers should do the Livestock confinement is the most spikes. trapping. effective control method, but it must be practical and economical. Frightening Landowners, however, can safely trap hawks and owls if they follow Confine free-roaming fowl in Use scarecrows and pyrotechnics. instructions and are careful when enclosures covered with netting or Erect electric pole shockers when handling the birds. woven wire. hawks or owls are observed around Shooting Condition poultry and fowl to move areas of potential damage. into coops or houses by feeding and State and federal permits are required Repellents watering them indoors at dusk. to shoot hawks and owls. They may None are registered. be issued only when there is a House them at night to protect them serious public health or depredation from owls. Toxicants problem and when nonlethal Habitat Modification None are registered. control methods fail or are Eliminate perch sites near areas of impractical. potential damage by removing large, isolated trees and snags.

PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994 Cooperative Extension Division Institute of Agriculture and Natural Resources University of Nebraska - Lincoln United States Department of Agriculture Animal and Plant Health Inspection Service Animal Damage Control E-53 Great Plains Agricultural Council Wildlife Committee Introduction flight pattern consists of several rapid extremely varied, usually contains wing beats, then a short period of glid- large numbers of rodents and other Hawks and owls are birds of prey and ing flight, followed by more rapid small mammals. Redtails occasionally are frequently referred to as raptors— wing beats. Accipiters are rarely seen take poultry and other livestock, but a term that includes the falcons, eagles, except during migration because they the benefits they provide in aesthetics, vultures, kites, ospreys, northern har- inhabit forested areas and are more as well as in the killing of rodents may riers, and crested caracaras. Food hab- secretive than many of the buteos. outweigh depredation costs. Other species of buteos rarely cause its vary greatly among the raptors. The largest and least common, but problems. Hawks and owls are highly specialized most troublesome, accipiter is the gos- predators that take their place at the hawk (Fig. 1). It is a bold predator that Owls, unlike hawks, are almost top of the food chain. Some are feeds primarily on forest-dwelling entirely nocturnal. Thus, they are far responsible for the loss of poultry or rodents, rabbits, and birds. Occasion- more difficult to observe, and much small game. In the past, raptors were ally, it is attracted by free-ranging less is known about them. They have persecuted through indiscriminate poultry or large concentrations of large heads and large, forward-facing shooting, poisoning, and pole trap- game birds and can cause depredation eyes. Their flight is described as noise- ping. The derogatory term chicken hawk problems. Its breeding range is limited less and mothlike. There are 19 species was used generically to identify rap- to Canada, the northern United States, of owls in the continental United tors, especially hawks, but has fallen and the montane forests of the western States. They range in size from the out of usage during the past two United States. Spectacular autumn tiny, 5- to 6-inch (12- to 15-cm) elf owl decades. Recently, many people have invasions of goshawks occur at irregu- (Micrathene whitneyi) that resides in the developed a more enlightened attitude lar intervals in the northern states. arid Southwest, to the large, 24- to 33- toward raptors and their place in the These are probably the result of wide- inch (60- to 84-cm) great gray owl environment. spread declines in prey populations (Strix nebulosa) that inhabits the dense People who experience raptor damage throughout the goshawk’s breeding boreal forests of Alaska, Canada, and problems should immediately seek range. Cooper’s hawks will occasion- the northern United States. ally cause problems with poultry; information and/or assistance. “Frus- The great horned owl (Bubo virgini- sharp-shinned hawks are rarely a tration killings” occur far too often anus, Fig. 1) is probably the most problem because of their small size. because landowners are unfamiliar widely distributed raptor in North with or unable to control damage with The buteos are known as the broad- America. Its range extends over almost nonlethal control techniques. These winged or soaring hawks. They are the all the continent except for the extreme killings result in the needless loss of most commonly observed raptors in northern regions of the Arctic. These raptors, and they may lead to undesir- North America. Typical species large and powerful birds are consid- able legal actions. If trapping or shoot- include the red-tailed hawk (Buteo ered to be the nocturnal complement ing is necessary, permits should be jamaicensis), red-shouldered hawk of the red-tailed hawk. Great horned requested and processed as quickly as (Buteo lineatus), broad-winged hawk owls generally prey on small- to possible. Always consider the benefits (Buteo platypterus), Swainson’s hawk medium-sized birds and mammals that raptors provide before removing (Buteo swainsoni), rough-legged hawk and will take poultry and other live- them from an area; their ecological (Buteo lagopus), and ferruginous hawk stock when the opportunity presents importance, aesthetic value, and con- (Buteo regalis). All buteos have long, itself. They are responsible for most tributions as indicators of environmen- broad wings and relatively short, fan- raptor depredation problems. tal health may outweigh the economic like tails. These features enable them to damage they cause. soar over open country during their daily travels and seasonal migrations. Damage and Damage Identification Identification and The red-tailed hawk (Fig. 1) is one of our most common and widely distrib- General Biology The most troublesome raptors are the uted raptors. Redtails can be found larger, more aggressive species, such over the entire North American conti- There are two main groups of hawks: as the goshawk, red-tailed hawk, and nent south of the treeless tundra and in accipiters and buteos. Accipiters are great horned owl. The majority of dep- much of Central America. They dem- the forest-dwelling hawks. North redation problems occur with free- onstrate a remarkably wide ecological American species include the northern ranging farmyard poultry and game tolerance for nesting and hunting sites goshawk (Accipiter gentilis), Cooper’s farm fowl. Chickens, turkeys, ducks, throughout their extensive range. hawk (Accipiter cooperii), and sharp- geese, and pigeons are vulnerable Typical eastern redtails nest in mature shinned hawk (Accipiter striatus). They because they are very conspicuous, forests and woodlots, while in the are characterized by distinctive flight unwary, and usually concentrated in Southwest they often nest on cliffs or silhouettes—relatively short, rounded areas that lack escape cover. Confined wings and a long rudderlike tail. Their in trees and cacti. Their diet, although

E-54 fowl that are chased by raptors will prey. In contrast, mammalian preda- Legal Status often pile up in a corner, resulting in tors such as skunks or raccoons often the suffocation of some birds. Repro- kill several animals during a night. All hawks and owls are federally pro- duction may also be impaired in some They will usually tear skin and muscle tected under the Migratory Bird Treaty fowl if harassment persists. tissue from the carcass and cut Act (16 USC, 703-711). These laws through the feathers of birds with their For years, game farms have dealt with strictly prohibit the capture, killing, or sharp teeth. raptor depredation problems. Large possession of hawks or owls without concentrations of game farm animals Hawks pluck birds, leaving piles of special permit. No permits are are strong attractants to predators. feathers on the ground. Beak marks required to scare depredating migra- Operators should consider the preven- can sometimes be seen on the shafts of tory birds except for endangered or tion of predation as part of their cost of these plucked feathers. Owls also threatened species (see Table 1), in- operation. Other depredation prob- pluck their prey, but at times they will cluding bald and golden eagles. lems include the loss of rabbits at swallow small animals whole. Many In addition, most states have regula- beagle clubs, the loss of homing and raptors (especially red-tailed hawks tions regarding hawks and owls. Some racing pigeons, and occasionally the and other buteos) feed on carrion. The species may be common in one state loss of farm or household pets. plucked feathers can often determine but may be on a state endangered spe- Cooper’s and sharp-shinned hawks whether a raptor actually killed an ani- cies list in another. Consult your local occasionally prey on songbirds that are mal or was simply “caught in the act” USDA-APHIS-Animal Damage Con- attracted to feeding stations. This of feeding on a bird that had died of trol, US Fish and Wildlife Service should be viewed as a natural event, other causes. If the feathers have small (USFWS), and/or state wildlife depart- however, and control of the raptors is amounts of tissue clinging to their ment representatives for permit not advisable. bases, they were plucked from a cold requirements and information. bird that died of another cause. If the There are occasions when raptors base of a feather is smooth and clean, cause human safety and health haz- the bird was plucked shortly after it Damage Prevention and ards. For example, concentrations of was killed. raptors at airports increase the risk of Control Methods bird-aircraft collisions and loss of hu- Raptors often defecate at a kill site. man life. The vast majority of aircraft Accipiters such as the goshawk leave a Exclusion strikes involve gulls, starlings, and splash or streak of whitewash that The ultimate solution to raptor depre- blackbirds, but a few raptor strikes radiates out from the feather pile, dation is prevention. Free-roaming have been documented. It is interest- whereas owls leave small heaps of farmyard chickens, ducks, and pigeons ing to note that falconers with trained chalky whitewash on the ground. attract hawks and owls and are highly hawks have been used to clear airport Hawks and owls regurgitate pellets susceptible to predation. Many prob- runways of other birds so that air- that are accumulations of bones, teeth, lems can be eliminated by simply planes can land. Although raptors are hair, and other undigested materials. housing poultry at night. They can be usually secretive and choose to avoid These are not usually found at the kill conditioned to move into coops or human contact, they occasionally nest site, but instead accumulate along with houses by feeding or watering them or roost in close association with whitewash beneath a nearby perch or indoors at dusk. If depredation per- humans. At such times, noise, prop- nest site. Fresh pellets, especially of sists, durable fenced enclosures can be erty damage, and aggressive behavior owls, are covered with a moist irides- constructed by securing poultry wire at nest sites can cause problems. cent sheen. They can be carefully to a wooden framework and covering Poultry and other livestock are vulner- teased apart and examined to learn the enclosure with poultry wire, nylon able to a wide range of predators. what the hawk or owl had been eating. netting, or overhead wires (Fig. 2). A Frequent sightings of hawks and owls Owls gulp their food and swallow double layer of overhead netting sepa- near the depredation site may be a clue many bones along with the flesh. rated by a 5- to 6-inch (12- to 15-cm) to the predator involved, but these These bones are only slightly digested space may be necessary to keep owls sightings could be misleading. When a and persist in the pellets. A pellet that away from penned birds. Large poul- partially eaten carcass is found, it is contains large bones, such as those try operations rarely have depredation often difficult to determine the cause from the leg of a rabbit, is undoubtably problems because most practice con- of death. In all cases, the remains must from a great horned owl. Hawks feed finement. be carefully examined. Raptors usually more daintily and have stronger diges- Habitat Modification kill only one bird per day. Raptor kills tive juices than owls. Thus, hawk pel- usually have bloody puncture wounds lets contain fewer bones. Habitat modification can make an area in the back and breast from the bird’s less attractive to raptors. Hawks and talons. Owls often remove and eat the owls often survey an area from a perch head and sometimes the neck of their prior to making an attack. Eliminate

E-55 Table 1. Federally endangered or threatened raptors. Pyrotechnics include a variety of exploding or noise-making devices. Name: California condor (Gymnogyps californianus) Status: Endangered The most commonly used are shell Where Endangered: US (California and Oregon), Mexico (Baja California). crackers, which are 12-gauge shotgun Name: Bald eagle (Haliaeetus leucocephalus) shells containing a firecracker that is Status: Endangered and Threatened projected 50 to 100 yards (45 to 90 m) Where Endangered: US (Conterminous states except Michigan, Minnesota, Oregon, before it explodes. Fire shell crackers Washington, and Wisconsin) in the direction of hawks or owls that Where Threatened: US (Michigan, Minnesota, Oregon, Washington, and Wisconsin) are found within the threatened area. Name: American peregrine falcon (Falco peregrinis anatum) Status: Endangered An inexpensive open-choke shotgun is Where Endangered: Nests from central Alaska across northcentral Canada to central recommended. Check the gun barrel Mexico. Winters south to South America. after each shot and remove any wad- Name: American peregrine falcon (Falco peregrinis tundrius) ding from the shells that may become Status: Threatened lodged in the barrel. Noise, whistle, Where Threatened: Nests from northern Alaska to Greenland. Winters south to Central and and bird bombs are also commercially South America. available. They are fired from pistols Name: Peregrine falcon (Falco peregrinis) and are less expensive to use than shell Status: Endangered Where Endangered: Wherever found in wild in the conterminous 48 states. crackers, but their range is limited to Name: Hawaiian (lo) hawk (Buteo solitarius) 25 to 75 yards (23 to 68 m). Your local Status: Endangered fire warden can provide information Where Endangered: US (Hawaii) on local or state permits that are Name: Everglade (snail kite) kite (Rostrhamus sociabilis plumbeus) required to possess and use pyro- Status: Endangered technics. Where Endangered: US (Florida) Name: Palau owl (Pyroglaux [=Otus] podargina) The electric pole shocker is a device Status: Endangered developed by R.W. Schmitt of Where Endangered: West Pacific Ocean: US (Palau Islands) Sheboygan, Wisconsin, to protect game farms and poultry operations (Fig. 3). It has proven very effective in several different settings in Wisconsin. Each unit consists of a ground wire perch sites within 100 yards (90 m) of Frightening running 1 inch (2.5 cm) from and par- the threatened area by removing large, There are many techniques that can be allel to a wire that is connected to an isolated trees and other perching sur- used to scare hawks and owls from an electric fence charger. Install electrical faces. Install utility lines underground area where they are causing damage. shocking units on top of 14- to 16-foot and remove telephone poles near poul- Some are inexpensive and easy to use, (4- to 5-m) poles and erect the poles try-rearing sites. Cap poles with sheet while others are not. The effectiveness around the threatened area at 50- to metal cones, Nixalite®, Cat Claws®, or of frightening devices depends greatly 100-foot (15- to 30-m) intervals. When inverted spikes. Improve rabbit escape on the bird, area, season, and method a raptor lands on a pole, it receives an cover at beagle clubs by constructing of application. Generally, if birds are electric shock and is repelled from the brush piles and cutting large trees to hungry, they quickly get used to and immediate area. Other perching sites increase the density of shrub and ignore frightening devices. Frightening in the area should be removed or ground cover. An abundance of rab- devices are usually a means of reduc- made unattractive. Energize the shock- bits will often attract raptors. Clubs ing losses rather than totally eliminat- ing unit only from dusk until dawn for should release only as many rabbits as ing them. Landowners who use them owls and during daylight hours for are needed for an outing. must be willing to tolerate occasional hawks. Hawks and owls that roost in build- losses. The electric pole shocker keeps raptors ings can be frightened away, or live Increasing human activity in the from perching within a threatened trapped and removed. Close off all threatened area will keep most raptors area but does not exclude them from entryways after the birds are out of the at a distance. The most common and nesting in or using a nearby area. Most building. Common barn owls are easily implemented frightening device hawks and owls are highly territorial. endangered in some states and rarely, is a shotgun fired into the air in the di- A pair that is allowed to remain will if ever, cause damage to poultry. Their rection of (not at) the raptor. Scare- aggressively defend the area and usu- use of farm buildings, where sanitation crows are effective at repelling raptors ally exclude other hawks and owls. problems associated with droppings when they are moved regularly and Thus, farmers may actually find it ben- pose no threat, should be encouraged. used in conjunction with shotgun fire eficial to coexist with a pair of hawks Consult your local wildlife agency for or pyrotechnics. or owls that have learned to avoid an information on barn owls in your area. area protected by pole shockers.

E-56 hardy, easily obtained, and move enough to attract hawks and owls. Other good lures include starlings, rats, and mice. For detailed informa- tion on the construction and use of Swedish goshawk traps, see Meng (1971) and Kenward and Marcstrom (1983). The bal-chatri trap is a relatively small, versatile trap that can be modified to Fig. 2. A complete enclosure can protect fowl trap specific raptor species (Fig. 5). and livestock from hawk and owl predation. Live mice are used to lure raptors into landing on the traps. Nylon nooses en- tangle their feet and hold the birds un- 7 til they are released. The quonset-hut type bal-chatri was designed for trap- 1 6 ping large hawks and owls (Berger 5 and Hamerstrom 1962). The trap is made of 1-inch (2.5-cm) chicken wire, formed into a cage that is 18 inches long, 10 inches wide, and 7 inches high at the middle (46 x 25 x 18 cm). The floor consists of 1-inch (2.5-cm) 2 mesh welded wire with a lure entrance door and steel rod edging for ballast. 3 The top is covered with about 80 4 nooses of 40-pound (18-kg) test monofilament fishing line (Fig. 5). Pigeons, starlings, house mice, and other small rodents can be used as Fig. 3. The electric pole shocker. (1) uninsulated (exposed) 12-gauge (0.28-cm) lures. The trap should be tied to a flex- copper, ground, and hot wires (no connec- ible branch or bush to keep a trapped tion from ground to hot wire) bird from dragging the trap too far (2) insulated wire to ground and breaking the nylon nooses. (3) insulated wire to fence charger agency to trap any hawk or owl that is causing damage. Trapping is usually (4) 14- to 16-foot (4- to 5-m) post Spring-net traps are ideal for catching (5) mounting screw permitted only after other nonlethal particular hawks or owls that are cre- (6) 1-inch x 6-inch (2.5- x 15-cm) self-insulat- techniques have failed. Set traps in the ating a damage problem (Fig. 6). ing plastic pipe threatened area where they can be (7) 3/4-inch (0.2-cm) sheet metal screws with Square spring nets, hoop nets, and the checked at least twice a day. If pos- plastic expansion sleeve or tubing between German “butterfly trap” have all been head of screw and plastic pipe sible, experienced individuals or used successfully. A trap is baited by agency personnel should conduct the attaching the partially eaten carcass of trapping and handling of captured Repellents and Toxicants a fresh kill or a stuffed bird to the trig- birds. ger bar. The trap should be camou- No repellents or toxicants are regis- flaged by covering the frame and tered or recommended for controlling The Swedish goshawk trap is a rela- folded net with leaves and feathers hawk or owl damage. In years past, tively large, semipermanent trap that from the kill. For detailed information raptors were killed by putting out car- can be used to capture all species of on spring-net traps see Kenward and casses laced with poison. This practice hawks and owls (Fig. 4). It consists of Marcstrom (1983). led to the indiscriminate killing of two parts: a 3 x 3 x 1-foot (90 x 90 x 30-cm) bait cage made of 1-inch (2.5- many nontarget animals. Concerns for Problem hawks and owls can be cm) mesh welded wire. A trap mecha- human safety also prompted the ban- trapped safely using the sliding pad- nism consisting of a wooden “A” ning of toxicants for raptor control. ded pole trap because of their ten- frame, nylon netting, and a trigger dency to perch prior to making an mechanism is mounted on the bait Trapping and Relocating attack (Fig. 7). Erect 5- to 10-foot cage. A hawk or owl dropping into the (1.5- to 3-m) poles around the threat- A landowner must obtain a permit trap will trip the trigger mechanism ened area where they can be seen eas- from the US Fish and Wildlife Service and be safely trapped inside. Pigeons ily and place one padded steel leghold and usually the local state wildlife make very good lures because they are

E-57 Nylon netting

Hinged 45° Trigger stick 3" 1"

5" 2"

25" 6"

3' Redwood 3' 6"

Removable bait cage (welded wire)

Fig. 4. The redesigned, modified, and improved Swedish goshawk trap developed by Meng (1971).

trap (No. 1 1/2) on top of each pole. most birds and make them less able to Select a box that is large enough for the The jaws must be well padded with defend themselves. Reach in carefully bird to stand upright in. Holes should surgical tubing or foam rubber and with your bare hands and grasp the be punched near the bottom of the box wrapped with electrician’s tape. Run a bird’s lower legs. Control the feet to to supply fresh air and keep the raptor 12-gauge steel wire through the trap avoid getting “footed.” Pull the bird from struggling toward any cracks of chain ring and staple it to the top and out of the trap so that it is clear of any light coming from the top of the box. bottom of the post. This allows the object on which it could injure itself. Carry only one bird per box. Tape an trap to slide to the ground where the Fold the wings down against the body old rag or towel to the floor to provide bird can rest. Some states prohibit the and hold them securely. Check the a good gripping surface to keep the use of pole traps. bird for any signs of external injury, bird from slipping. If a burlap bag such as cut feet or legs, excessively bat- must be used to transport the bird, tie Handling and Transportation. If tered feathers, or scalping (the splitting the bird’s legs together with a nylon necessary, landowners can safely of the skin over the forehead). If the stocking to keep it from footing some- handle and transport hawks and owls. bird is injured, have a local veterinar- one during transport or release. If pos- The key to successful raptor handling ian examine it, or in extreme cases, sible, ask a local bird bander to attach is to control the bird’s feet. The talons transport it to the nearest raptor reha- a leg band. Banding information can can easily grasp a careless hand and bilitation center. be very useful to the research and inflict a painful injury. There is signifi- management of raptors. cantly less chance of injury from the Raptors should be restrained before wings and beak. The safest approach, they are transported to reduce the Transport the bird as quickly and regardless of the type of trap, is to toss chances of injury to both the bird and comfortably as possible. Minimize an old blanket or coat over both the handler. The best transport container excess handling, and above all, keep bird and trap. The darkness will calm is a stout, covered cardboard box. the bird calm and cool. More birds die

E-58 7"

a 18"

10"

1/4" steel rod

Fig. 5. (a) Big bal-chatri trap ready for nooses (door is open). (b) Method of attaching nooses.

b

Fig. 6. Automatic spring-net trap in set position; inset with bait.

26" 48"

E-59 of overheating during shipment than of any other cause. Transport the bird as far away from the trapping site as possible. Some biologists believe that 20 miles (32 km) is sufficient, but rap- 1/2 turn only tors have been known to travel up to light wire 200 miles (320 ) km after release. If a bird is trapped in the fall, help it along Heavy staple its way by transporting it southward. each side Shooting All hawks and owls are protected by Size of federal and state laws. There are cases, jump trap-1 1/2 however, in which they can create public health and safety hazards or seriously affect a person’s livelihood. Contact your local USDA-APHIS- ADC office first if you are interested in obtaining a shooting permit. The USFWS and state wildlife agencies may issue shooting permits for prob- See insert above lem hawks and owls if nonlethal meth- ods of controlling damage have failed or are impractical and if it is deter- mined that killing the offending birds will alleviate the problem.

Permittees may kill hawks or owls Secure heavy only with a shotgun not larger than wire 10-gauge, fired from the shoulder and only within the area described by the permit. Permittees may not use blinds or other means of concealment, or decoys or calls that are used to lure birds within gun range. Exceptions to the above must be specifically After capture, authorized by USFWS. All hawks or bird must owls that are killed must be turned be allowed over to USFWS personnel or their to rest on representatives for disposal. ground

Economics of Damage and Control

In 1985, we conducted a national sur- vey of US Fish and Wildlife Service and Cooperative Extension personnel. Nearly all noted that the economic damage caused by raptors is minimal on a national scale, but can be locally severe if depredation occurs on fowl or livestock that are relatively valuable and vulnerable. Cost estimates of damage ranged from $10 to $5,000 per report and from $70 to $94,000 per year. The severity of Fig. 7. Sliding padded pole trap.

E-60 raptor problems is influenced by For Additional Meng, H. 1971. The Swedish goshawk trap. J. Wildl. Manage. 35:832-835. several factors, including prey and car- Information rion abundance, weather, time of year, Newton, I. 1979. Population ecology of raptors. husbandry methods, vegetative cover, Buteo Books, Vermillion, South Dakota. Berger, D. D., and F. Hamerstrom. 1962. 399 pp. and topography as well as density and Protecting a trapping station from raptor local distribution of raptors. predation. J. Wildl. Manage. 26:203-206. Peterson, L. 1979. Ecology of great horned owls and red-tailed hawks in southeastern Hamerstrom, F. 1972. Birds of prey of Wisconsin. Wisconsin Dep. Nat. Resour. Wisconsin. Wisconsin Dep. Nat. Resour. Tech. Bull. 111. Madison. 63 pp. Acknowledgments 64 pp. Salmon, T. P., and F. S. Conte. 1981. Control of Hamerstrom, F. 1984. Birding with a purpose. We wish to thank Fran and Frederick N. bird damage at aquaculture facilities. WML Iowa State Univ. Press, Ames. 130 pp. Hamerstrom for their comments on early No. 475. US Dep. Inter. Fish Wildl. Serv., Washington, D.C. 11 pp. manuscripts and information regarding the Heintzelman, D. S. 1979. Hawks and owls of handling of raptors. Reviewers included North America. Universe Books, New York. US Fish and Wildlife Service. (no date). Raptor Richard H. Behm, James L. Ruos, Leroy W. Sowl, 197 pp. control-protecting livestock from hawk and V. Dan Stiles, and Richard Winters. Eldon L. owl predation. US Dep. Inter. An. Damage Karlbom, M. 1981. Techniques for trapping McLaury reviewed the manuscript and Control Bull. 211-1-77. provided legal information. goshawks. Pages 138-144 in R. E. Kenward and I. Lindsay, eds. Understanding the Figure 1 by Elva Hamerstrom Paulson, from goshawk, Internat. Assoc. Falconry Conserv. Hamerstrom (1972). Birds of Prey. Figure 2 from Salmon and Conte (1981). Kenward, R. E., and V. Marcstrom. 1981. Editors Goshawk predation in game and poultry: Scott E. Hygnstrom Figure 3 by the authors. some problems and solutions. Pages 152-162 Robert M. Timm Figure 4 from Meng (1971). in R. E. Keward and I. Lindsay, eds. Gary E. Larson Understanding the goshawk. Internat. Assoc. Figure 5 from Berger and Hamerstrom (1962). Falconry Conserv. Birds of Prey. Figure 6 from Kenward and Marcstrom (1983). Kenward, R. E., and V. Marcstrom. 1983. The Figure 7 from US Department of Interior, price of success in goshawk trapping. Raptor Bulletin 211-1-77. Res. 17:84-91.

E-61 E-62