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Full-Text Articles in Population Biology
Response Of Florida Sandhill Cranes To Nest Inspection, Stephen A. Nesbitt, Paul S. Kubilis, Stephen T. Schwikert
Response Of Florida Sandhill Cranes To Nest Inspection, Stephen A. Nesbitt, Paul S. Kubilis, Stephen T. Schwikert
Proceedings of the North American Crane Workshop
We observed the response of nesting Florida sandhill cranes (Grus canadensis pratensis) to 27 instances of nest inspection. The disturbed bird flew from the area 81% and walked 19% of the time. The median distance moved was 330 meters (range 28 to 480 meters). The median length of time the nest was left unattended following inspection was 50 min (range: 10 to 166 min). The median length of time that observers stayed at the nest was 16 min (range: 5 to 48 min). Ten of the nests inspected (40%) eventually failed to produce young. Statistical analysis was focused …
Injuries And Abnormalities Of Sandhill Cranes Captured In Florida, Stephen A. Nesbitt, Marilyn G. Spalding, Stephen T. Schwikert
Injuries And Abnormalities Of Sandhill Cranes Captured In Florida, Stephen A. Nesbitt, Marilyn G. Spalding, Stephen T. Schwikert
Proceedings of the North American Crane Workshop
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.
Techniques Employed To Capture Whooping Cranes In Central Florida, Martin J. Folk, Stephen A. Nesbitt, Stephen T. Schwikert, James A. Schmidt, Kathleen A. Sullivan, Thomas J. Miller, Stephen B. Baynes, Jeannette M. Parker
Techniques Employed To Capture Whooping Cranes In Central Florida, Martin J. Folk, Stephen A. Nesbitt, Stephen T. Schwikert, James A. Schmidt, Kathleen A. Sullivan, Thomas J. Miller, Stephen B. Baynes, Jeannette M. Parker
Proceedings of the North American Crane Workshop
During the course of re-introduction of a non-migratory flock of whooping cranes to Florida (1993-2002) a variety of techniques were used to capture 105 free-living birds. The most commonly used technique was hand-capture from a feed trough blind (45 birds). Whooping cranes were also captured by use of snares, several types of nets, and by hand. All techniques were relatively safe and posed little risk to the birds, a primary concern when dealing with rare birds. We found it useful to employ a diversity of techniques because some methods work better than others under differing circumstances. Capturing whooping cranes for …
Translocation Of Florida Sandhill Cranes To Georgia, Wesley A. Abler, Stephen A. Nesbitt
Translocation Of Florida Sandhill Cranes To Georgia, Wesley A. Abler, Stephen A. Nesbitt
Proceedings of the North American Crane Workshop
Wild Florida sandhill cranes (Grus canadensis pratensis) were captured in Florida during 3 years and translocated to Grand Bay Wildlife Management Area (GBWMA), Georgia, in an attempt to establish a resident population of Florida sandhill cranes in a location with suitable habitat but no known population of resident sandhill cranes. Translocated second-year subadult cranes commingled with migratory greater sandhill cranes (G. c. tabida) yet remained on GBWMA each year after the migratory birds left the area. Twenty-one of 35 released cranes were visually identified at least 5 months after release, 3 cranes more than 15 months …
The Use Of Radio Transmitters To Monitor Survival Of Sandhill Crane Chicks, Marilyn G. Spalding, Stephen A. Nesbitt, Stephen T. Schwikert, Robert J. Dusek
The Use Of Radio Transmitters To Monitor Survival Of Sandhill Crane Chicks, Marilyn G. Spalding, Stephen A. Nesbitt, Stephen T. Schwikert, Robert J. Dusek
Proceedings of the North American Crane Workshop
To determine cause of death of Florida sandhill crane (Grus canadensis pratensis) chicks, in 1996-99 we glued shorttenn transmitters on newly hatched chicks. At about 10 days of age, these were replaced with surgically implanted subcutaneous transmitters in the field. Chicks were then recaptured at 55 to 65 days of age for more pennanent transmitters. This combination of transmitter configurations allowed us to track individuals through their rapid-growth period.
Aspects Of Reproduction And Pair Bonds In Florida Sandhill Cranes, Stephen A. Nesbitt, Martin J. Folk, Stephen T. Schwikert, James A. Schmidt
Aspects Of Reproduction And Pair Bonds In Florida Sandhill Cranes, Stephen A. Nesbitt, Martin J. Folk, Stephen T. Schwikert, James A. Schmidt
Proceedings of the North American Crane Workshop
From 1980-98 we captured and uniquely marked more than 400 Florida sandhill cranes (Grus canadensis prafensis). Age ratios of the marked population, excluding juveniles, was 66% adult and 33% subadult, and the sex ratio was 49% male and 51% female. Average clutch size for 210 nests checked from 1983-97 was 1.78 ± 0.18 (SD) and frequency of l-egg clutches varied among years. Average post-fledging brood size from 1991 to 1997 was 1.27 ± 0.17 (SD), included a 3-chick brood. Average percent ofYOlmg from 2 study areas, 1991-97 was 11.9 ± 3.23 (SD). We observed renesting up to 3 …
Water Conditioning And Whooping Crane Survival After Release In Florida, George F. Gee, Jane M. Nicolich, Stephen A. Nesbitt, Jeff S. Hatfield, David H. Ellis, Glenn H. Olsen
Water Conditioning And Whooping Crane Survival After Release In Florida, George F. Gee, Jane M. Nicolich, Stephen A. Nesbitt, Jeff S. Hatfield, David H. Ellis, Glenn H. Olsen
Proceedings of the North American Crane Workshop
About 50% of the whooping cranes (Grus americana) released in Florida die within the first year of release. Most of these deaths and those in subsequent years result from bobcat (Lynx rufus) predation. Choosing release sites in open marshes away from bobcat habitat has improved survival. We hypothesized that exposure to ponds (water conditioning) at the rearing site would encourage birds to roost in deeper water marshes after release and such exposure would thereby reduce bobcat predation. In this study, we moved young birds (ca 50 days of age) to netted pens with large (I5-m diameter), deep (30--60 …
Interactions Of Sandhill Cranes And Whooping Cranes With Foreign Objects In Florida, Martin J. Folk, Stephen A. Nesbitt, Marilyn G. Spalding
Interactions Of Sandhill Cranes And Whooping Cranes With Foreign Objects In Florida, Martin J. Folk, Stephen A. Nesbitt, Marilyn G. Spalding
Proceedings of the North American Crane Workshop
During studies of Florida sandhill cranes (Grus canadensis pralensis), greater sandhill cranes (G. c. tabida), and whooping cranes (G. americana) in Florida, we documented cases where these birds were in contact with human-produced objects that resulted in injury or death. We describe >40 instances in which cranes collided with powerlines or fences, became entangled in string or fishing line, or ingested foreign objects. The effect of human-produced objects on crane populations, particularly small populations, may be significant.
Ingested Metal In Whooping Cranes: An Endoscopic Technique For Removal And Implications For The Release Program, Glenn H. Olsen, Michael Wise
Ingested Metal In Whooping Cranes: An Endoscopic Technique For Removal And Implications For The Release Program, Glenn H. Olsen, Michael Wise
Proceedings of the North American Crane Workshop
Since 1993 when the whooping crane (Grus americana) release program in Florida started, 21 whooping cranes at the USGS Patuxent Wildlife Research Center (patuxent) have been diagnosed with gastrointestinal foreign bodies (primarily metal objects). A technique for safely removing these objects has been developed. The technique uses a flexible gastric endoscope to enter the proventriculus or ventriculus, and a snare or forceps passed down a channel of the endoscope to retrieve the foreign bodies. The technique is very successful, with the whooping crane usually back to its pen the next day. The longterm survival of the whooping cranes …
An Experimental Release Of Whooping Cranes In Florida - The First Three Years, Stephen A. Nesbitt, Martin J. Folk, Marilyn G. Spalding, James A. Schmidt, Stephen T. Schwikert, Jane M. Nicolich, Marianne Wellington, James C. Lewis, Tom H. Logan
An Experimental Release Of Whooping Cranes In Florida - The First Three Years, Stephen A. Nesbitt, Martin J. Folk, Marilyn G. Spalding, James A. Schmidt, Stephen T. Schwikert, Jane M. Nicolich, Marianne Wellington, James C. Lewis, Tom H. Logan
Proceedings of the North American Crane Workshop
Fifty-two juvenile whooping cranes (Grus americana) were soft-released in Florida from February 1993 to April 1995. The birds were released in groups ranging in size from 5 to 14 individuals. The first-year survival rate was 0.42 for all years combined. First-year rates for each year were 0.36 for 1993, 0.32 for 1994, and 0.47 for 1995. Most mortality (62%) occurred during the first 3 months following release. The survival rate of 0.81 the second year after release was similar to that of Florida sandhill cranes (G. canadensis pratensis) (0.87). Predation by bobcats (Lynx rufus) …
Habitat Use By Florida Sandhill Cranes On The Kissimmee Prairie In Central Florida, Mary Anne Bishop
Habitat Use By Florida Sandhill Cranes On The Kissimmee Prairie In Central Florida, Mary Anne Bishop
Proceedings of the North American Crane Workshop
Radio-tagged Florida sandhill cranes (Grus canadensis pratensis) were monitored for habitat use during 1985 and 1986 on the Kissimmee Prairie in central Florida. For both breeding and nonbreeding cranes, 93 % of the daytime locations were in 3 habitat types: cropland and plowed pasture, improved pasture, and palustrine emergent wetlands. Improved pasture was the most frequently used daytime habitat for both social classes. Radio locations were divided among 4 time blocks (3 diurnal, 1 nocturnal) and 4 3-month seasons. Time-of-day effects for use of wetlands and improved pasture were only marginally significant (1' < 0.08 and l' < 0.09, respectively) for breeders and not significant (1' < 0.30 and l' < 0.43, respectively) for nonbreeders. There was no significant difference in habitat use by breeders among seasons. Chi-square analyses of diurnal locations indicated that 4 of the 6 breeding cranes monitored used palustrine emergent wetlands more than their availability. The selection for wetlands reflects not only the rich food sources available, but also their use as midday loafing and drinking sites and as a source of cover that the upland habitats do not offer.
Gender Prediction From Body Measurements Of Two Subspecies Of Sandhill Cranes, Stephen A. Nesbitt, Clinton T. Moore, Kathleen S. Williams
Gender Prediction From Body Measurements Of Two Subspecies Of Sandhill Cranes, Stephen A. Nesbitt, Clinton T. Moore, Kathleen S. Williams
Proceedings of the North American Crane Workshop
Linear discriminant functions estimated from leg length, bill length and body weight measurements of known subspecies and known gender (KS-KG) Florida (FSH) and greater sandhill cranes (GSH) (Grus canadensis pratensis and G. c. tabida, respectively) were used to predict gender of known subspecies and unknown gender (KS-UG) individuals. Mean body measurements were larger among males than among females of either subspecies, but the difference in mean bill length between genders was larger among GSH than among FSH cranes. Gender misclassification was less frequent among GSH than among FSH cranes. Of birds whose measurements fell outside of the 80% …