Northern Prairie Wildlife Research Center
Variation in Body Mass of Wild Canvasback and Redhead Ducklings
Jane E. Austin and Jerome R. Serie
Abstract: We assessed variation in body mass of ducklings in
single- and mixed-species broods of wild Canvasbacks (Aythya valisineria)
and Redheads (Aythya americana) 20-50 days old. Body mass of canvasback
ducklings was not affected by year and season (early vs. late hatch date)
despite changes in water conditions. Mean body mass of male and female Canvasbacks
did not differ in Class IIA but did differ in older age classes. Within-brood
differences in body mass tended to be higher in Class IIA ducklings (6-7%
of mean body mass for Canvasbacks, 9-11% in Redheads) and generally declined
to 4-6% in Class IIC and older ducklings. Some within-brood differences were
as high as 20-30% of mean body mass. Tests to assess sources of within-brood
variation (age, sex, and season) in body mass for Canvasbacks were inconclusive.
Variation within broods was generally less than that among broods for both
Canvasbacks and Redheads. The lack of differences in duckling body mass between
single- and mixed-species broods for any age class, sex, or species suggests
that mass was not affected by interspecific brood parasitism.
Key words: Aythya americana, Aythya valisineria,
duckling, brood, body mass, Canvasback, Redhead.
This resource is based on the following source (Northern Prairie Publication
0918):
Austin, Jane E., and Jerome R. Serie. 1994. Variation in body mass
of wild canvasback and redhead ducklings. Condor 96:909-915.
This resource should be cited as:
Austin, Jane E., and Jerome R. Serie. 1994. Variation in body mass
of wild canvasback and redhead ducklings. Condor 96:909-915.
Jamestown, ND: Northern Prairie Wildlife Research Center Online.
http://www.npwrc.usgs.gov/resource/birds/bodymass/index.htm
(Version 12MAY03).
Table of Contents
Tables
- Table 1 -- Mean differences in body
mass of Canvasback and Redhead ducklings within broods by age class.
- Table 2 -- Mean body mass of Canvasback
ducklings, expressed as LSMEANS, by age class and sex.
- Table 3 -- Variance in body mass of
Canvasback and Redhead ducklings among and within broods, by age class.
- Table 4 -- Mean body mass of Canvasback
ducklings by age, sex, and brood type.
- Table 5 -- Mean body mass of Redhead
ducklings by age, sex, and brood type.
Jane E. Austin, National Biological Survey, Northern Prairie
Science Center, Jamestown, ND 58401-7317
Jerome R. Serie, U.S. Fish and Wildlife Service, Office of Migratory
Bird Management, Patuxent Environmental Science Center, Laurel, MD 20708
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Variation in Body Mass of Wild Canvasback and Redhead Ducklings
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