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Full-Text Articles in Population Biology
Timing Of Molt In Florida Sandhill Cranes, Stephen A. Nesbitt, Stephen T. Schwikert
Timing Of Molt In Florida Sandhill Cranes, Stephen A. Nesbitt, Stephen T. Schwikert
Proceedings of the North American Crane Workshop
We observed feather molt in Florida sandhill cranes (Grus canadensis pratensis) between 1978 and 1997. We report data from 4 feather groups: remiges, rectrices, wing coverts and contour feathers. In all feather groups, the median date of ecdysis preceded endysis by about 30 days. Endysis in adults was generally later than it was in first- or second-year subadults. Remiges grew at a rate of 4.72 ± 1.56 SD mm per day. We estimated that primary and secondary wing feathers were usually regenerated within 45 to 70 days.
Survival And Sources Of Mortality In Florida Sandhill Crane Chicks – Hatching To Fledging, Stephen A. Nesbitt, Stephen T. Schwikert, Marilyn G. Spalding
Survival And Sources Of Mortality In Florida Sandhill Crane Chicks – Hatching To Fledging, Stephen A. Nesbitt, Stephen T. Schwikert, Marilyn G. Spalding
Proceedings of the North American Crane Workshop
Forty-five pairs of Florida sandhill cranes (Grus canadensis pratensis) were monitored during the nesting seasons from 1996 through 1999. Thirty-eight chicks were produced from 25 successful nests. Twenty-one of these survived to fledging age. Predation was the source of most (81%) of the mortality for which a cause was determined. Mammals were the primary predator. Average age at time of mortality was 27.2 days for the 17 chicks lost.
Interaction Of Young Florida Sandhill Cranes With Their Parents, Stephen A. Nesbitt, Paul S. Kubilis, Stephen T. Schwikert
Interaction Of Young Florida Sandhill Cranes With Their Parents, Stephen A. Nesbitt, Paul S. Kubilis, Stephen T. Schwikert
Proceedings of the North American Crane Workshop
We studied the interactions of 46 Florida sandhill crane (Grus canadensis pratensis) chicks and their parents from hatching until the chicks left the family group. Our goal was to see if young remained closer to one parent than the other and if the distance between a chick and its parents increased as the young approached the age of independence. Using a population of individually marked adult pairs, we ranked the distance to and gender of the nearest parent during 233 30-minute observation periods. Between hatching and 180 days of age, chicks showed a greater tendency to be nearer …
Body Mass Index (Bmi) Of Normal Sandhill Cranes, Stephen A. Nesbitt, Marilyn G. Spalding, Kristen L. Candelora, Paul S. Kubilis, Stephen T. Schwikert
Body Mass Index (Bmi) Of Normal Sandhill Cranes, Stephen A. Nesbitt, Marilyn G. Spalding, Kristen L. Candelora, Paul S. Kubilis, Stephen T. Schwikert
Proceedings of the North American Crane Workshop
We used linear and mass measurements to construct a body mass index (BMI) for 2 subspecies of sandhill cranes (Grus canadensis). We found that BMI declined during the spring and early summer period. We used the BMI to show that juvenile Florida sandhill cranes (G. c. pratensis) reach their full mass at about 270 days of age, near the age at which they begin to leave the company of their parents. We used mensural data to predict a minimum expected mass for normal sandhill cranes which could be then used to evaluate the relative health of …
Trends In Habitat And Population Of Florida Sandhill Cranes, Stephen A. Nesbitt, James L. Hatchitt
Trends In Habitat And Population Of Florida Sandhill Cranes, Stephen A. Nesbitt, James L. Hatchitt
Proceedings of the North American Crane Workshop
To map the areas of potential occupied habitat for Florida sandhill cranes (Grus canadensis pratensis) in Florida we used known habitat requirements and confirmed locations of occurrence in combination with a Geographic Information System. Using the map of potential habitat resulting from this process, we calculated the changes in the amount and distribution of crane habitat in Florida in 10-year increments since 1974. Based on annual home range sizes, age structure, and average flock size, we estimated the statewide population of Florida sandhill cranes in 2003 to be 4,594 individuals. Considering the area of crane habitat lost since …
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 …
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 …
Food And Feeding Habits Of Released Florida Sandhill Cranes, Christine R. Rucker
Food And Feeding Habits Of Released Florida Sandhill Cranes, Christine R. Rucker
Proceedings of the North American Crane Workshop
Food habits of 4 pairs of free-ranging Florida sandhill cranes (Grus canadensis pratensis) on St. Catherine's Island, Georgia, were studied from May to October 1990. Food items were identified and quantified at close range « 10 m). The 4 pairs varied in how they used plant and animal resources (P < 0.0001). Animal material in the diets averaged 19.1 % and ranged from 13.4 to 36.7%. Plant material averaged 80.9% in the pairs' diets. Major foods included subsurface bulbs, roots, and tubers of yellow star grass (Hypoxis micrantha), catbrier (Smilax glauca), and false garlic (Allium bivalva), longleaf pine seeds (Pinus palustris), and insects. Food habits shifted seasonally for all pairs (P < 0.(001). In July and August the percent occurrences of yellow star grass and false garlic in the diets were > 50 %. During September and October pine seed occurrence was > 75 % in the diets of …