Northern Prairie Wildlife Research Center
Conditioning of Sandhill Cranes During Fall Migration
Gary L. Krapu and Douglas H. Johnson
Abstract: Body mass of adult female and male sandhill cranes
(Grus canadensis) increased an average of 17 and 20%, respectively,
from early September to late October on staging areas in central North Dakota
and varied by year. Increases in body mass averaged 550 and 681 g among female
and male G. c. canadensis, respectively, and 616 and 836 g among female
and male G. c. rowani. Adult and juvenile G. c. rowani were
lean at arrival, averaging 177 and 83 g of fat, respectively, and fat reserves
increased to 677 and 482 g by mid-October. Fat-free dry mass increased by
12% among juveniles, reflecting substantial growth, but remained constant
among adults. The importance of fall staging areas as conditioning sites for
sandhill cranes, annual variation in body mass, and vulnerability of cranes
to habitat loss underscore the need to monitor status of fall staging habitat
in the northern plains region and to take steps to maintain suitable habitat
where necessary.
This resource is based on the following source (Northern Prairie Publication
0757):
Krapu, Gary L., and Douglas H. Johnson. 1990. Conditioning of sandhill cranes
during fall migration. Journal of Wildlife Management 54(2):234-238.
This resource should be cited as:
Krapu, Gary L., and Douglas H. Johnson. 1990. Conditioning of sandhill cranes
during fall migration. Journal of Wildlife Management 54(2):234-238.
Jamestown, ND: Northern Prairie Wildlife Research Center Online.
http://www.npwrc.usgs.gov/resource/birds/crancond/index.htm
(Version 25JUL2002).
Table of Contents
Figures
- Figure 1 -- Body mass curves of adult
male and female sandhill cranes by 10-day intervals during fall in central
North Dakota.
- Figure 2 -- Population marginal means
of body mass of sandhill cranes in central North Dakota, 1970-87.
- Figure 3 -- Body composition of juvenile
and adult sandhill cranes collected during early fall and late fall in
central North Dakota.
Gary L. Krapu and Douglas H. Johnson, U.S. Fish and Wildlife
Service, Northern Prairie Wildlife Research Center, P.O. Box 2096, Jamestown,
ND 58402* (*Current address: U.S. Geological Survey, Northern Prairie
Wildlife Research Center, 8711 37th Street Southeast, Jamestown, ND 58401)
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