Ecology of the Greater Sandhill Crane in Central Wisconsin

File(s)
Date
1977Author
Howard, Thomas Jackson
Publisher
University of Wisconsin-Stevens Point
Metadata
Show full item recordAbstract
This study was designed to obtain information
pertinent to greater sandhill crane (Grus canadensis
tabida) productivity, habitat requirements, distribution,
and seasonal abundance to facilitate management of the
species. The field study was conducted in the central
Wisconsin sand counties and was designed to investigate
characteristics associated with greater sandhill crane
reproduction and breeding habitat in central Wisconsin.
Other objectives of the study included determinations of
greater sandhill crane distribution and abundance in
Wisconsin and identification of migration routes, staging
areas, and wintering areas of Wisconsin's greater sandhil cranes.
Fifty sandhill crane nests were located by helicopter
early in the nesting seasons of 1974 and 1975. The mean
size of marshes occupied by nesting cranes was 31.5 ha
(1.6-151.8 ha). Dominant vegetation in these marshes
included Sphagnum spp., Carex rostrata, Scirpus cyperinus,
Carex lasiocarpa, Salix spp., Typha latifolia, Spirea
tomentosa, Carex oligosperma, and Calamagrostis canadense.
These species comprised over 80 percent of the vegetation
present within 10 m of nests. Nests averaged 91 cm in
diameter (65-125 cm), 16.9 em in height (7-31 cm), and
were located in sites which averaged 12.55 cm in water
depth (0.13-31. 88 em). Nests averaged 1714 m from sources o£ human activity (305-5630 m), 280 m from open water
(11-1280 m), and 785 m from the nearest road (100-1905 m).
Hatching occurred from 17 May to 17 June and shell
thickness of eggshells averaged 0.26 mm (0.20-0.36 mm).
Seventy percent of the eggs hatched between 19 and 30
May. Average clutch size was 1.84 and hatching success
was 80.44 percent.
Seventy-seven cranes were captured and color-marked
with patagial tags in central Wisconsin during premigration
staging. All captured cranes belonged to the
tabida subspecies. Sightings of color-marked cranes
indicated that the major flyway staging area of marked
cranes during fall migration is the Jasper-Pulaski
Refuge in northwestern Indiana and that their major
wintering area is in the north-central prairies and
marshes of Florida and southern Georgia.
A mail survey was conducted through the Wisconsin Department of Natural Resources during June and July of
1975. A Wisconsin resident population of 780 adults
(including 223 pairs) and 118 young of the year was
reported. No cranes were reported from 26 counties, and
12 counties in central Wisconsin (Wood, Adams, Marquette,
Green Lake, Portage, Marathon, Juneau, Clark, Columbia,
Shawano, Jackson, and Monroe) accounted £or over 75
percent of the cranes reported.
Permanent Link
http://digital.library.wisc.edu/1793/79473Type
Thesis