USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Effects of Harness Transmitters on Behavior and Reproduction of Wild Mallards

Tables

Table 1. Sample sizes and Hotelling's T 2-values (Johnson and Wichern 1988) used to assess behavioral differencesa between unmarked and radio-marked female mallards on 2 study sites in the prairie pothole region, 22 April-30 June 1989-91.
  Total observation time (hr)b No. radio-marked birds observedc Overall behavioral difference
Unmarked birds Radio-marked birds T 2 P
Detroit Lakes, Minn.
1989 92 105 13 37.3 0.0004
1990 60 44 13 16.2 0.0128
1991 38 36 10 18.3 0.0129
All years 190 185 36d 47.4 <0.0001
Kulm, N.D.
1989 78 42 14 20.2 0.0050
1990 113 8 3 e e
All years 191 50 17f 23.3 0.0018
a Test evaluates combined differences in feeding, resting, and preening behaviors.
b Calculated from number of data points collected at 30-second intervals rounded to the nearest hour.
c Radio-marked birds observed in >1 year were counted separately for each year.
d Three or 4 radio-marked birds were each observed in 2 years. Second year observations totaled 5-7 hours for the 3-4 birds combined.
e Not tested because of insufficient data on radio-marked birds.
f One radio-marked bird possibly observed in 2 years (observed 1.4 hr in second year).

 

Table 2. Clutch sizes and egg volumes for unmarked and radio-marked female mallards nesting on 3 study sites in the prairie pothole region, 1988-91.
  Clutch sizea Egg volume (cm3)a
mean of x SE nb mena of x SE nc
Detroit Lakes, Minn.
  Unmarked 9.7(9.1) 0.20(0.24) 56(37) 50.0(49.9) 0.23(0.27) 331(252)
  Radio-marked 8.0(8.0) 0.18(0.18) 51(50) 48.4(48.4) 0.25(0.26) 552(542)
Kulm, N.D.
  Unmarked 9.2(8.8) 0.15(0.22) 80(39) 49.4(49.8) 0.20(0.29) 351(161)
  Radio-marked 7.9(7.9) 0.22(0.25) 34(29) 46.5(46.7) 0.24(0.28) 338(264)
Jamestown, N.D.
  Unmarked 9.7(9.4) 0.17(0.19) 54(35) 49.5(49.7) 0.25(0.31) 230(124)
  Radio-marked 8.3(8.6) 0.51(0.69) 20(14) 46.3(45.9) 0.29(0.31) 156(110)
a Parenthetical values are for data subsets that only included nests initiated during the time interval in which both unmarked and radio-marked females initiated nests.
b Number of clutches.
c Number of eggs.

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/birds/wildmal/tables.htm
Page Contact Information: Webmaster
Page Last Modified: Friday, 01-Feb-2013 20:06:45 EST
Menlo Park, CA [caww54]