Despite state and federal protection, raptors are still being shot, trapped, poisoned, and kept illegally as pets. And with the spread of the human population into wildlife habitat, many more raptors are being injured or displaced as a result of direct or indirect human activities — collision with vehicles or power lines, cutting down of nest trees, and loss of habitat to development.
One approach to the dilemma of declining raptor populations is a raptor rehabilitation program. Sick, injured, and orphaned birds of prey are treated and cared for until returned to the wild.
For the last four years the Wachiska Audubon Society has sponsored a raptor rehabilitation program. Prior to Wachiska's involvement, personnel from Omaha's Henry Doorly Zoo were involved in raptor rehabilitation, and they provided Wachiska with information on the costs and requirements for a successful rehabilitation program. The foremost requirement is acquisition of federal and state permits to handle and transport protected species. However, these permits are not given until three other requirements are met: knowledgeable people (licensed falconers) to provide expertise; a reliable food source; and adequate housing. The final requirements for operation are veterinary services at cost, and an adequate number of volunteers to maintain efficient operation of the program. Preliminary organization and meeting of these requirements took eight months to complete. By the fall of 1976, Wachiska was ready to receive its first patients.
General Medical Treatment
Upon arrival at the center, each raptor is assigned a number. Information on date and location found, who found it, and under what condition is recorded. The bird is then given a physical examination to determine extent of injuries. The mouth is opened and examined closely for signs of disease (such as trichomoniasis or tuberculosis), parasites (gapeworm, roundworm, flukes), and general condition. Very pale color in the mouth could denote shock, serious blood loss, or anemia. Blue colored mouth tissue means an inadequate oxygen supply, probably due to respiratory distress. Sticky mucous is a sign of dehydration, and immediate steps to re-hydrate the bird are taken.
The breast muscle on each side of the keel is then palpated to determine if there is any degree of starvation. If the keel can be felt easily between thumb and forefinger, the bird is emaciated.
With one person holding the bird on its back with the head covered, another person examines each wing and leg for fractures and dislocations. Each wing is extended as fully as possible, and all bones are palpated along the entire length. The same is done for each leg. Fresh fractures can be located by the sound and feel of the two ends rubbing against each other. Older fractures are usually located by swelling of the callus at the break site.
Since most injured birds are not found until they're weak enough to be caught, dehydration and some degree of starvation are usually present. The bird is given Gatorade to provide both fluids and energy initially, then water and food. A starving, emaciated bird cannot be given food too quickly, or the sudden intake of food can kill it. Very tiny amounts, every few hours, are given until the digestive system returns to normal.
Treatment of wing fractures depends on the situation (Garcelon and Bogue 1977). A simple fracture can usually be immobilized by taping the wing to the body, in such a way as to not impede breathing or assimilation of food. This tape is left on two to three weeks, then removed. The wing is then gently manipulated to resume mobility. The bird is then placed into a series of larger fight cages until it regains its strength and use of the wing, when it can be released.
Compound fractures present a more serious problem, and generally require a longer stay at the rehabilitation center. The fracture is surgically pinned, and the wing is taped to the body for one to two weeks. During this time, antibiotics are administered. Hetacin K is used at a rate of 50 mg/lb. twice a day in the food. The bird is housed in a special cardboard box during the recovery period. The box is bottomless, has a perch nailed in about halfway up. This enables the volunteer to remove the newspapers for easy cleaning without handling the bird. A door and window slots are cut to allow the bird to see some of his surroundings. Hawks and eagles adapt readily to such housing, eat well, and heal quickly because they feel secure.
Facilities and Operation
Primary housing for birds is in two converted cattle barns. Separate portions of the barns have been partitioned off into cages of various sizes. (Figure 1). Different size cages accommodate different species. Smaller cages are used for smaller birds such as Screech Owls, Kestrels and Broad-winged Hawks. The larger hawks, falcons, eagles, and owls are usually placed in those cages with more available room. Each cage contains a tree stump or board for use as a feeding site. All perches in the cages are canvas-covered and placed to minimize possible feather damage to wings or tails. A water pan is also placed in each cage to supply fresh water.
Figure 1. Diagrammatic view of program facilities. Walls are shown from the inside, (i.e., folded down). Distance between barns not to scale.
The lofts of both barns are open and used for flight training birds. Prior to release, birds are placed in a loft to permit free flight. This exercise improves muscle tone and flight capabilities and continues until sustained flight is possible. The bird is then either released directly into the wild or a hacking procedure is used. Direct or free release of the bird in a suitable habitat is most commonly used while hacking involves post-release feeding. The released bird has freedom to come and go, with feeding continued to provide food for birds until they are successful hunters.
Food types for the birds have included deer, fox, and coyote meat, pocket gophers, squirrels, chickens, mice, and rats. Whole rat carcasses from university programs are the primary food type. These are fed whole, or in portions for the smaller birds. Carcasses are obtained and kept frozen until use. Storage lockers enable storage for extended periods. This storage is necessary to provide the essential stable food supply.
The food is thawed before use. Complete thawing is a must in cold winter months to allow birds a chance to eat before the carcass refreezes. Other months do not require complete thawing as warmer temperatures will thaw food being used. The birds feed on the thawed portion of the food, or do not feed until the carcass has completely thawed. Incomplete thawing in summer months delays decay. Decay associated with uneaten food can result in fly and maggot problems. For this reason it is vital that uneaten portions of food are removed daily to control flies and maintain sanitary conditions.
Fresh water is another necessity for birds. Water is placed in water pans as needed, with fresh clean water always present. In winter months, thawed water is maintained only for certain species such as Barn Owls, which are heavy water users. (Other birds obtain sufficient water from the food eaten.) In this case fresh warm water is put in the water pan. Although this eventually freezes it does supply water for a sufficient time to be utilized by the owls.
Each cage has a sign-up sheet where date, food type and amount given or removed, feeder initials, and notes are recorded. These individual feeding sheets insure proper feeding and give records of food consumption and general behavior of birds.
Source of Birds
Raptors received by the program originate mostly from the eastern third of the state. Species such as Golden Eagles, Ferruginous Hawks, and Prairie Falcons are generally received from western regions.
Patients come primarily from state and federal game officials, local officials, and the general public. Birds from outlying areas are best taken to Lincoln in heavy construction cardboard boxes to keep the birds calm. It is best when birds are received as soon as possible so severely injured birds can receive necessary and quick treatment.
Injuries Survey
Three hundred and thirty-five birds were received for treatment during the period from November 1976 through October 1980. Of the twenty-four species, the Red-tailed Hawk, American Kestrel, Great Horned Owl, and Screech Owl made up 70 percent of all birds handled (Table 1).
Table 1. Injuries of raptors received.
June, December, and July were the three months during which the most birds per month were received (Table 2). The next highest month was May, followed by January, November, and March. Orphaned birds received in March, April, and June contributed somewhat to birds received in these months (Table 3). May, however, is the month when orphaned birds were most frequently received. Eighty-five percent of the birds received in May have been orphans. Higher numbers of incoming birds in July could be due to inexperience of fledged young. In the process of learning, these immature birds could more likely be injured. December and January levels could result from severe winter weather and the birds' inability to survive winter hardships.
Table 2. Monthly total of raptors received. | |||||||||||||
Ja | Fe | Mr | Ap | My | Je | Jl | Au | Sp | Ot | No | Dm | Total | |
Falconiformes | |||||||||||||
Number | 15 | 14 | 12 | 4 | 8 | 22 | 7 | 6 | 10 | 17 | 15 | 28 | 158 |
Percent | 9.4 | 8.8 | 7.5 | 2.5 | 5.1 | 13.9 | 4.4 | 3.8 | 6.3 | 10.8 | 9.5 | 18.0 | 100.0 |
Strigiformes | |||||||||||||
Number | 12 | 4 | 13 | 16 | 25 | 38 | 28 | 8 | 8 | 6 | 10 | 9 | 177 |
Percent | 6.8 | 2.3 | 7.3 | 9.0 | 14.1 | 21.5 | 15.8 | 4.5 | 4.5 | 3.4 | 5.7 | 5.1 | 100.0 |
Total | |||||||||||||
Number | 27 | 18 | 25 | 20 | 33 | 60 | 35 | 14 | 18 | 23 | 25 | 37 | 335 |
Percent | 8.0 | 5.4 | 7.4 | 6.0 | 9.9 | 17.9 | 10.4 | 4.2 | 5.4 | 6.9 | 7.5 | 11.0 | 100.0 |
Trauma injuries such as fracture of legs, wings, or other bones, sprains, joint injuries, and concussion were the most common injuries. Orphans were the next highest group received, followed by birds which had no injury apparent. Many of the birds had injuries which were a direct or indirect result of man's influence, such as collision with a power line or a fence or as a result of traps, firearms, collision with cars, or having the nest tree destroyed. Gun-shot and trap-injured birds often suffered the most severe physical injury.
Table 3. Orphaned birds received, by species and month. | |||||||||||||||||||||||||||
| Mr | Ap | My | Je | Jl | Au | Sp | ||||||||||||||||||||
| No. | % of No. line | No. | % of No. line | No. | % of No. line | No. | % of No. line | No. | % of No. line | No. | % of No. line | No. | % of No. line | |||||||||||||
Turkey Vulture | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | 2 | 100.0 | -- | -- | |||||||||||||
Red-tailed Hawk | -- | -- | -- | -- | 4 | 80.0 | 1 | 20.0 | -- | -- | -- | -- | -- | -- | |||||||||||||
Marsh Hawk | -- | -- | -- | -- | -- | -- | 1 | 50.0 | 1 | 50.0 | -- | -- | -- | -- | |||||||||||||
American Kestrel | -- | -- | 1 | 25.0 | -- | -- | 3 | 75.0 | -- | -- | -- | -- | -- | -- | |||||||||||||
Barn Owl | -- | -- | -- | -- | -- | -- | 4 | 40.0 | 3 | 30.0 | -- | -- | 3 | 30.0 | |||||||||||||
Screech Owl | -- | -- | 2 | 6.5 | 12 | 38.7 | 8 | 25.8 | 9 | 29.0 | -- | -- | -- | -- | |||||||||||||
Great Horned Owl | 5 | 20.8 | 6 | 25.0 | 9 | 37.5 | 3 | 12.5 | 1 | 4.2 | -- | -- | -- | -- | |||||||||||||
Barred Owl | -- | -- | -- | -- | 3 | 100.0 | -- | -- | -- | -- | -- | -- | -- | -- | |||||||||||||
Total | 5 | 6.2 | 9 | 11.1 | 28 | 34.5 | 20 | 24.7 | 14 | 17.3 | 2 | 2.5 | 3 | 3.7 | |||||||||||||
Final fate of the birds received was dependent on the nature of the injury. Those seriously injured would often die in captivity or were euthanized (Table 4). Others which were non-releasable would be used for captive breeding or in research or educational programs.
Table. 4. Final disposition of birds handled. | |||||||||||
| Falconiformes | Strigiformes | Total | ||||||||
| No. | % of column | No. | % of column | No. | % of column | |||||
Died in captivity | 32 | 20.2 | 30 | 16.9 | 62 | 18.5 | |||||
Euthanized | 15 | 9.5 | 20 | 11.3 | 35 | 10.4 | |||||
Educational or Research | 15 | 9.5 | 9 | 5.1 | 24 | 7.2 | |||||
Breeding | 8 | 5.1 | 5 | 2.8 | 13 | 3.9 | |||||
Released | 76 | 48.1 | 104 | 58.8 | 180 | 53.7 | |||||
Still on hand | 12 | 7.6 | 9 | 5.1 | 21 | 6.3 | |||||
Total | 158 | 100.0 | 177 | 100.0 | 335 | 100.0 | |||||
Release rate for this program thus far has been 53.7%. This compared with release rates of 39.6% (Snelling 1975), 40% (Fuller and Redig 1974), and 47% (Wisecarver and Bogue 1974) in other programs in the country. A major influence on the rate of release has been the number of orphan birds received and released. Birds still on hand due to long recovery periods or other reasons comprises 6.3 percent of the birds handled.
Other Methods and Treatments
Every rehabilitation program is eventually faced with the problem of what to do with birds that will never recover sufficiently to survive in the wild. The loss of an entire foot, a part of either or both wings, or loss of vision renders a bird non-releasable. Final disposition of a non-releasable raptor depends upon the extent of the injury, the species, and the personality of the bird (especially ability to adapt to captivity without undue stress). First choice is to place the bird in a captive breeding program. This constitutes the best use of the bird in most circumstances. If a breeding program cannot be found, and the bird is easily handled without stress, it can be placed into an educational program or exhibit. This is a good use for human-imprinted raptors, which do not respond to their own kind. Third choice is to use the bird in avian physiology research programs. The final choice in euthanasia. Sometimes a raptor has injuries so severe, and is so stressed by captivity, that euthanasia is the only humane choice.
Release of a bird is dependent on several factors. Release criteria include judgements of flight ability, feeding ability, aggressive behavior resulting from fear of humans, and general physical condition (McKeever 1979). A missing toe, drooping wing or other physical abnormality resulting from injury will not necessarily prevent a bird from being released. All birds released have sufficiently recovered from their injury to enable survival in the wild.
Treatment of Orphaned Birds
Springtime brings an influx of orphaned owls and hawks. When these birds are found in the wild they may or may not actually be orphaned. It is essential that persons finding young birds be certain the birds are orphaned. If a bird is thought to be an orphan efforts should first be made to locate the nest or to determine if the parents are in the area and still caring for their young. If the nest is located, return the bird(s) to it. If adult birds are in the vicinity, leave the young where they are. When young raptors fledge and leave the nest the adults still care for and feed them. Only if the birds are surely orphaned should they be taken to be raised in captivity; they are best raised in the wild by natural parents.
As a group, orphans form the highest percentage of releases, mainly because they aren't injured, but are still unable to survive on their own. Older chicks and fledglings can be successfully placed into foster nests with young of the same approximate age. If an active nest cannot be found, these youngsters are placed in flight cages with minimal human contact, and hacked out when they have attained flight ability. Very young downy chicks must be handled differently. They are kept warm at 90°F. with use of a heating pad. Food is given in tiny pieces, and fortified with vitamins and minerals. Proper nutrition is vital, or the growing chick will not develop properly, and will be debilitated for the rest of its life (McKeever 1979). A serious problem facing a single chick which has to be hand-reared is imprinting to humans. Two or more chicks will imprint on each other and eventually learn to fear humans. A human-imprinted hawk or owl will not relate to its own kind, and if released will be relegated to inferior hunting areas. If it survives to adulthood, it will seek out a human mate (Hamerstrom 1975).
One way to prevent imprinting is to make a hand puppet resembling the adult, especially the outline of the head. The baby is fed by the mandibles of the puppet, and does not see the human. Approximate sounds of the adult raptor should be made, and the chick should be gently caressed often, to give it the impression of being constantly attended. This is important to the psychological well-being of the bird (McKeever 1979). As the chick gets older, it should show fear of humans, and can be hacked out when it is ready to go.
Conclusion
There are many merits of a raptor rehabilitation program. It provides information on characteristics and behavior of a variety of species, and adds to the knowledge of those species. It enables release back to the wild of raptors which would otherwise have died. A rehabilitation program can greatly increase public knowledge and awareness of the value of birds of prey, and promote active public involvement in protecting these birds.
An additional benefit of a rehabilitation program is use of non-releasable raptors in a breeding program. Wachiska Audubon has begun a captive breeding program for Barn Owls with the cooperation of the Nebraska Game and Parks Commission. Captive-raised Owls released from this program will augment a declining population in the state.
Why bother to save birds which would have died from natural causes? Because the vast majority of birds brought in were not injured naturally, but as a direct or indirect result of man's activities. A rehabilitation program puts some human activity on the side of the raptors.
Wachiska's raptor rehabilitation program has fostered cooperation among several groups and governmental agencies which would not have occurred otherwise. Good working relationships exist with the Nebraska Game and Parks Commission, the U.S. Fish and Wildlife Service, and others. The program is in touch with the Ager Memorial, Folsom Children's and Henry Doorly Zoos concerning raptors turned in or donated to them. The Wachiska chapter has grown as a result the sponsorship of the rehabilitation program, and most of the rehabilitation volunteers are Audubon members. The success of the program has been dependent upon the expertise of local licensed Falconers. who have been involved with this program since its beginning. The Wachiska Chapter has received support from other Audubon chapters in the state. one of which (Audubon Society of Omaha) has begun a raptor transport system to bring injured birds to the Lincoln facilities.
Most importantly, Wachiska's educational efforts have served to increase public awareness of birds of prey and their ecological role, and the necessity to protect these unique and valuable birds. For this reason alone, the rehabilitation program is definitely worthwhile.
Acknowledgments
The success of a raptor rehabilitation program depends upon the cooperation and dedication of many people. It is a team effort. We would like to thank Dave and Cindy Cochran, Bruce and DeAnn Currin, Mike Cox, Carol Odell, Bob and Karl Linderholm, and Doug Krieger and other volunteers whose contributions have been vital to this program.
Special thanks to Sharon Ducey and Linda Cox for their patient and professional typing, and Ross Lock for editorial comments.
Literature Cited
Fuller, M.R. and P.T. Redig. 1974. Raptor rehabilitation and conservation in Minnesota. Raptor Research, 8(12): 11-19.
Garcelon, D and G.L. Bogue. 1977. Raptor care and rehabilitation. Night Owl Press, California. 143 pp.
Hamerstrom, F. 1975. Introducing captive reared raptors into the wild. In World Conference on Birds of Prey, pp. 348-353,
McKeever. K. 1979. Care and rehabilitation of injured owls. W.F. Rannie, Lincoln, Ontario. 112 pp.
Snelling, J.C. 1975. Raptor rehabilitation at the Oklahoma City Zoo. Raptor Research, 9(3 4): 33-39.
Wisecarver, J. and G. Bogue. 1974- Raptor rehabilitation at the Alexander Lindsay Junior Museum. Raptor Research, 8(1/2): 6-10.
Jim Ducey and Betsy Hancock. December 1981. Nebraska Bird Review 49(4): 58-64.