. Bulletin. Natural history; Natural history. Sept., 1970 Bellrosk & Crompton: Micrational Behavior of Ducks limited movements occurred during non- hunting periods. The passage of mal- lards into the northern zone is somewhat obscured by breeding birds already present in that zone together with an early passage into it from the Canadian zone prior to the hunting season. Band recoveries suggest that mallard populations reached their greatest abun- dance in the various zones as follows: Canadian, September 20-26; northern, October 25-31; central, November 8- 15; southern, December 27-January
. Bulletin. Natural history; Natural history. Sept., 1970 Bellrosk & Crompton: Micrational Behavior of Ducks limited movements occurred during non- hunting periods. The passage of mal- lards into the northern zone is somewhat obscured by breeding birds already present in that zone together with an early passage into it from the Canadian zone prior to the hunting season. Band recoveries suggest that mallard populations reached their greatest abun- dance in the various zones as follows: Canadian, September 20-26; northern, October 25-31; central, November 8- 15; southern, December 27-January 3. The greatest time lag between periods of greatest abundance was between the central and southern zones, indicating C-CANADIAN N-NORTHERN Cn-CENTRAL S-SOUTHERN. T 1 1 1 1 1 1 1 1 1 1^ I ' I 1 1 1 1 II 13 20 27 4 11 18 25 I 8 15 22 29 6 13 20 27 3 10 17 24 SEPT. OCT. NOV. DEC. JAN. Rg. 21 recoveries ii — Yearly variation, 1940-1942, in the seasonal distribution of indirect mallard four regions of North Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Illinois. Natural History Survey Division. Urbana, State of Illinois, Dept. of Registration and Education, Natural History Survey Division
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Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
