Observations of gross pathological abnormalities were made during handling of sandhill cranes (Grus canadensis) captured for banding in Florida. One hundred fifty-six of 1,331 (11.7%) cranes examined showed evidence of one or more anomalies that were the result of disease, congenital deformity, or injury. Most frequent were abnormalities of the legs and feet, followed by abnormalities of the bill. Injuries of the eyes, head, and neck were also noted. Many of these birds were observed subsequent to banding and survived for several years with their injuries, though some never succeeded in reproducing

NESBITT, STEPHEN A.

SCHWIKERT, STEPHEN T.

SPALDING, MARILYN G.

English

DigitalCommons@University of Nebraska

University of Nebraska - LincolnDigitalCommons@University of Nebraska - LincolnNorth American Crane Workshop Proceedings North American Crane Working Group2005INJURIES AND ABNORMALITIES OFSANDHILL CRANES CAPTURED INFLORIDASTEPHEN A. NESBITTFlorida Fish & Wildlife Conservation Commission, Wildlife Research Laboratory, steve.nesbitt@MyFWC.comMARILYN G. SPALDINGUniversity of FloridaSTEPHEN T. SCHWIKERTFlorida Fish & Wildlife Conservation Commission, Wildlife Research LaboratoryFollow this and additional works at: http://digitalcommons.unl.edu/nacwgprocPart of the Behavior and Ethology Commons, Biodiversity Commons, Ornithology Commons,Population Biology Commons, and the Terrestrial and Aquatic Ecology CommonsThis Article is brought to you for free and open access by the North American Crane Working Group at DigitalCommons@University of Nebraska -Lincoln. It has been accepted for inclusion in North American Crane Workshop Proceedings by an authorized administrator ofDigitalCommons@University of Nebraska - Lincoln.NESBITT, STEPHEN A.; SPALDING, MARILYN G.; and SCHWIKERT, STEPHEN T., "INJURIES AND ABNORMALITIES OFSANDHILL CRANES CAPTURED IN FLORIDA" (2005). North American Crane Workshop Proceedings. 20.http://digitalcommons.unl.edu/nacwgproc/20      15INJURIES AND ABNORMALITIES OF SANDHILL CRANES CAPTURED IN FLORIDASTEPHEN A. NESBITT1, Florida Fish & Wildlife Conservation Commission, Wildlife Research Laboratory, 4005 South Main   Street, Gainesville, FL 32601, USAMARILYN G SPALDING, Department of Pathobiology, Box 110880, University of Florida, Gainesville, FL 32611, USASTEPHEN T. SCHWIKERT, Florida Fish & Wildlife Conservation Commission, Wildlife Research Laboratory, 4005 South   Main Street, Gainesville, FL 32601, USAPROCEEDINGS NORTH AMERICAN CRANE WORKSHOP  9:15-20Abstract:  Observations of gross pathological abnormalities were made during handling of sandhill cranes (Grus canadensis) cap-tured for banding in Florida. One hundred fifty-six of 1,331 (11.7%) cranes examined showed evidence of one or more anomalies that were the result of disease, congenital deformity, or injury.  Most frequent were abnormalities of the legs and feet, followed by abnormalities of the bill.  Injuries of the eyes, head, and neck were also noted.  Many of these birds were observed subsequent to banding and survived for several years with their injuries, though some never succeeded in reproducing. Key words: pathology, cranes, disease, Florida, Grus canadensis, injuries, sandhill cranes. The Florida Fish and Wildlife Conservation Commission began capturing sandhill cranes (Grus canadensis) for banding in 1968 (Williams and Phillips 1972).  After 1974, as part of an expanded study of plumage (Nesbitt and Schwikert 1998), each crane handled was examined incidentally for signs of injury or disease.  The number of cranes we handled each year increased after 1980 when we accelerated banding and color marking of sandhill cranes as part of a program to determine the feasibility of establishing a non-migratory population of whooping cranes (G. americana) in Florida (Nesbitt et al 1997).  Here we pres-ent a summary of type, frequency of occurrence, and possible consequence on life history of gross physical abnormalities that were due to congenital deformities, disease or trauma sustained under free ranging conditions, i.e. not capture related.  Capture related injuries and mortalities were rare and addressed in an-other paper (Nesbitt 1984).METHODS Cranes were captured in north central Florida, on or near Paynes Prairie State Preserve (29°36'N, 82°13'W) in Alachua County.  Captures were made with the use of alpha-chloralose as described in Nesbitt (1975) and Bishop (1991).  Each bird was weighed and measured (see Nesbitt et al. 1992) when cap-tured; during subsequent recaptures only weights were consis-tently recorded.  However, each time a bird was handled it was checked for any signs of gross pathology or abnormalities.  Le-sions observed within the oral cavity, which were commonly seen, are not included here. In 1974, a scheme was implemented to uniquely color mark each crane captured (Nesbitt et al. 1992).  This facilitated moni-toring individual cranes post-capture and allowed us to evaluate ________1 Corresponding author, e-mail: steve.nesbitt@MyFWC.comhow abnormalities effected survival and behavior in subsequent years.RESULTS From 1974 through 1999, 1,331 cranes were examined, including 365 recaptured birds.  Of these, 156 (11.7%) had de-tectable injuries or abnormalities.  Several of these anomalies dramatically altered the crane’s appearance and, in all likeli-hood, its ability to function normally. A 2.6 year old female captured 30 November 1989 had several tumors on both legs.  One of these was a large (6 cm diameter) benign tumor on the tibiotarsal joint of the right leg (Fig. 1) and there were a number of smaller tumors on both legs.  The combined effect of these lesions was enough to in-terfere with the bird’s ability to walk.  The bird died during surgery to remove the larger tumors. Six other cranes we cap-tured had lesions that appeared similar, though much reduced. These tumors contained viral particles.  The virus causing these tumors has not yet been identified, but poxvirus, which occurs in sandhill cranes (Simpson et al. 1975, Forrester and Spalding 2003), was ruled out. We captured 5 individuals that had suffered fracture to the tibiotarsus or tarso-metatarsus that had apparently healed spontaneously.  The majority of these birds appeared normal. However, one bird was left with a severely twisted leg and an unnatural gait.  Deformities of the legs were seen in 5 other cranes that were missing part of the lower leg or a foot. Several of these cranes were seen following release.  Those that lost a lower leg were either never seen again or only seen for a few days after release.  Some of the birds with healed leg or toe fractures were seen for up to 2 years after release.  One individual of unknown sex was seen 23 times over a period of 4 years following initial capture, but was never recorded as paired.  Another crane observed 7 times over 3 years following initial capture was seen as a member of a pair, but never with 16   ABNORMALITIES IN SANDHILL CRANES · Nesbitt et al.                          Proc. North Am. Crane Workshop     9:2005          young. We recorded 25 abnormalities of the bill, the second most frequently seen deformation.  One individual, with a severely crossed bill (Fig. 2), was captured first as a chick in the company of its parents.  It was unable to feed itself after leaving the fam-ily and when recaptured, soon after separating from its parents, had lost nearly 50% of its mass and was obviously starving. Efforts to correct the deformity were unsuccessful and the bird was euthanized.  Seven other individuals with severely crossed, bowed, or broken bills seemed to be able to survive with the defect and form pair bonds, but none ever succeeded in repro-ducing.  One crane, first captured as a chick, had a deformation of the bill that left it noticeably de-curved (Fig. 3). The bird was seen 24 times between 4 September 1987 and 16 January 1991. It did form pair bonds with several individuals, but they never lasted more than a few days. Three of the 5 cranes captured that were blind in one eye were seen for several years following initial banding.  One seen 50 times between 15 September and 26 October 1991 was paired with 4 different birds, but never produced young.  An-other individual seen 23 times between 1 August 1984 and 23 September 1986 was paired and nested, but never successfully reproduced.  The third single-eyed bird was seen 13 times be-tween 17 December 1984 and 21 December 1988, but never noted as paired.  The other 2 cranes blind in one eye were not seen again after the year of capture.  The scarred combs and necks of 11 individuals were per-haps the result of conspecific attacks.  We have seen 3 aggres-sive encounters between individuals that resulted in mortality Fig. 2. Crossed-bill of a subadult Florida sandhill crane captured in Florida 17 April 1987.Fig. 1. Tumors on the right leg of a subadult sandhill crane cap-tured in Florida 30 November 1989.Proc. North Am. Crane Workshop     9:2005                          ABNORMALITIES IN SANDHILL CRANES · Nesbitt et al.    17Fig. 3. De-curved bill of a subadult Florida sandhill crane captured in Florida 4 May 1988.Fig. 4. Scarred comb of subadult male Florida sandhill crane captured in Florida 3 August 1983.18   ABNORMALITIES IN SANDHILL CRANES · Nesbitt et al.                          Proc. North Am. Crane Workshop     9:2005          (Nesbitt unpublished field observations).  In all cases death was from stabbing to the back of the head.  A sub-lethal attack like this would leave a scar such as shown in Figure 4.  A dead crane that was reported by the observer to have fallen from the sky out of a passing flock, had a wound to the back of the head (consistent with an aggressive attack) indicating it might have been attacked in flight by another crane. We observed 2 instances of birds kicking forward during handling that resulted in a long neck laceration from a toenail. Such wounds, which could occur during territorial disputes, would leave a similar scar.  This may also explain the bird with a portion of its tongue protruding out through the cervical skin (Fig. 5) of an adult female crane.  The crane was seen 49 times between initial capture on 24 February 1983 and 5 May 1989.  When seen it was always paired with the same individual though they never produced young. The abnormal tongues of four other cranes could have re-sulted  from disease, injuries, or congenital abnormalities. Although the parasite has not been documented in sandhill cranes, we observed capillarid nematodes and eggs present on the tongue of a whooping crane, resulting in a noticeable defor-mity (Forrester and Spalding 2003). A juvenile crane captured 19 March, 1990 exhibited a severely deformed neck (Fig. 6). It was examined and radio-graphed at the University of Florida School of Veterinary Medi-cine and was determined to have scoliosis.  This individual was seen 6 times between capture on 19 March 1990 and 3 February 1992.  Though it survived with the condition, and was able to migrate, it was never seen paired. We handled several other cranes with individually unique Fig. 5. Adult sandhill crane captured in Florida 24 February 1983 showing injury to the throat which left the base of the tongue exposed.Fig. 6. Juvenile sandhill crane captured in Florida 19 March 1990 showing neck deformation due to scoliosis.Proc. North Am. Crane Workshop     9:2005                          ABNORMALITIES IN SANDHILL CRANES · Nesbitt et al.    19peculiarities.  One bird had white middle toenails on both feet. Another had double nails on the hallux of each foot (Fig. 7). The tarsi of a third individual were noticeably flattened on the ventral aspect.  Reasons for these abnormalities were not obvi-ous; they could have been genetic or due to injuries that oc-curred early in the bird’s development.DISCUSSION Some of the injuries to the legs and feet may be a conse-quence of collisions with power lines or injuries from fences. Power transmission lines are known to cause mortality in cranes (Walkinshaw 1956, Krapu 1974).  Adverse weather conditions can increase mortality associated with power lines (Wheeler 1966).  Marking of lines has been an effective way to reduce instances of collision (Brown and Drewien 1995).  Agricultural fencing has caused death and leg injury to cranes, but potential impacts can be reduced (Wood and Nesbitt 2001).  Based on our observations it is apparent some cranes survive impacts with fences and power lines, although depending on the extent of injury, they may not be capable of functioning normally after recovery. Losses of the legs and feet for sandhill cranes significantly affected their ability to walk or stand normally and likely inter-fered with their ability to feed normally or defend themselves against aggression from other cranes and predators.  Causes could not be determined with certainty, but the loss of a foot or lower leg could follow a fracture that failed to heal and became necrotic.  Such losses of distal extremities also could have fol-lowed frostbite to the feet or toes that led to appendage necrosis (Calle et al. 1982).  Deformation of the bill, often first seen in chicks, may in some cases have been the result of injuries suf-fered soon after hatching, while their bills were growing rap-idly. Approximately 12% of the sandhill cranes we handled had noticeable signs of injury or disease.  While many of them sur-vived initially, in some cranes the long term effect may have compromised their ability to function normally.  While surviv-able, the loss of a leg or foot, the loss of an eye, or a signifi-cant deformation of the bill may reduce a bird’s opportunity to secure a mate, feed their young, or otherwise successfully reproduce.ACKNOWLEDGMENTS The Florida Fish and Wildlife Conservation Commission, Nongame Trust Fund and the United States Fish and Wildlife Service through Section 6 of the Endangered Species Act (PL Fig. 7. Bilateral doubling of hallux on juvenile female sandhill crane from Florida 16 October 1985.20   ABNORMALITIES IN SANDHILL CRANES · Nesbitt et al.                          Proc. North Am. Crane Workshop     9:2005          93–205) provided funding for this study.  We thank Barry Hart-up, and an anonymous reviewer, as well as Judith Buhrman, and Jennifer Swan for their review of this manuscript and many suggested improvements.  The Florida Department of Environ-mental Protection, C.L. Brice and Company, and Dr. W. Mur-phy kindly allowed us to capture cranes on their property.LITERATURE CITEDBishop, M. A. 1991. Capturing cranes with Alpha–chloralose   (an oral tranquilizer). Pages 247–253 in J. Harris, editor.  Proceedings [1987] international crane workshop. Interna- tional Crane Foundation, Baraboo, Wisconsin, USA.Brown, W. M., and R. C. Drewien. 1995. Evaluation of two   power line markers to reduce crane and waterfowl colli-  sion mortality. Wildlife Society Bulletin 23:217–227.Calle, P. P., R. J. Montali, D. L. Janssen, M. K. Stoskopf, and   J.D. Strandberg. 1982. Distal extremity necrosis in captive  birds. Journal of Wildlife Diseases 18:473–479.Forrester, D.J., and M.G. Spalding. 2003. Parasites and diseas-  es of wild birds in Florida. University Press of Florida,  Gainesville, Florida, USA.Krapu, G. L. 1974. Avian mortality from collisions with over-  head wires in North Dakota. Prairie Naturalist 6:1–6.Nesbitt, S. A. 1976. Capturing cranes with oral tranquilizers.   Pages 296–298 in J. C. Lewis, editor. Proceedings 1975  International crane workshop. Oklahoma State University,  Stillwater, Oklahoma, USA._______.1984. Effects of an oral tranquilizer on survival of   sandhill cranes. The Wildlife Society Bulletin 12:387– 388._______, R. D. Bjork, K. S. Williams, S. T. Schwikert, and A.  S. Wenner. 1992. An individualized marking scheme for  sandhill cranes and its use to determine fall migration in- terval. Pages 43–46 in D. A. Wood, editor. Proceedings  1988 North American crane workshop. Florida Game and   Fresh Water Fish Com mission, Tallahassee, USA.______, C. T Moore, and K.S. Williams. 1992. Gender pre-  diction from body measurements of two subspecies of  sandhill cranes. Proceeding North American Crane Work- shop 6:38–42.______, M. J. Folk, M. G. Spalding, J. A. Schmidt, S. T.   Schwikert, J. M. Nicolich, M. Wellington, J. C. Lewis,   and T. H. Logan. 1997. An experimental release of   whooping cranes in Florida - the first three years.  Pro-  ceeding North American Crane Workshop 7:79–85.______ and S. T. Schwikert. 1998. Maturation and variation in   head characteristics in sandhill cranes. Wilson Bullein   110: 285–288.Simpson, C. F., D. J. Forrester, and S. A. Nesbitt. 1975. Avian   pox in Florida sandhill cranes. Journal of Wildlife Diseas-  es 11:112–115Walkinshaw, L. H. 1956. Sandhill cranes killed by flying into   power lines. Wilson Bulletin 68: 325–326.Wheeler, R. H. 1966. Sandhill crane casualties in the blizzard   of March 22, 1966. Nebraska Bird Review 34:69–70.Williams, L. E., Jr. and R. W. Phillips. 1972. North Florida   sandhill cranes populations. Auk 89:541–548.Wood, D. A., and S. A. Nesbitt. 2001. Sandhill Crane. Pages   108–123 in D. A. Wood, editor. Florida’s Fragile  Wildlife:  Conservation and Management. University Press of Flori- da, Gainesville, Florida, USA.

INJURIES AND ABNORMALITIES OF SANDHILL CRANES CAPTURED IN FLORIDA

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INJURIES AND ABNORMALITIES OF SANDHILL CRANES CAPTURED IN FLORIDA

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