. Bulletin. Natural history; Natuurlijke historie. DISCUSSION 101 26th, cloudy but light wind still westerly. One hundred and eight birds passed Sandy Beach on the 27th, clear and calm, and 70 on the 28th, still calm, but cloudy. Although the 29th was warm and rainy, 20 thrushes were recorded but none called on the 30th, a very warm morning with hght rain and fresh south-southeast winds. Again September 2 to 7 pro- vided good migration weather that brought sustained flights. The conspicuous exception to the "fair weather rule," to which attention has already been called, was the 2-da
. Bulletin. Natural history; Natuurlijke historie. DISCUSSION 101 26th, cloudy but light wind still westerly. One hundred and eight birds passed Sandy Beach on the 27th, clear and calm, and 70 on the 28th, still calm, but cloudy. Although the 29th was warm and rainy, 20 thrushes were recorded but none called on the 30th, a very warm morning with hght rain and fresh south-southeast winds. Again September 2 to 7 pro- vided good migration weather that brought sustained flights. The conspicuous exception to the "fair weather rule," to which attention has already been called, was the 2-day migration out of the Cascapedia Auq. 1947 Sept. /r 16 IT ia /9 _ 3 4 S b 7 t 9 fO '/ I2 '3 /4 /f /« // 19 /9 '.OS/. ^. .86 .77 ,68 ^9 . -,â - Hsilocichla 6 * 2"" '^ ^" ^*' '*â 'â ''' â "' ^° "^ â¢'' â "' / Sef/.J948 13. 3 4 S 6 7 6 <) /o // fi. /3 /a- /f /6 /7 /a /f zo 21 !Z 23 i* 2s j» 3 $ in. .Jo â 2/ ./2 .03 29-9* .86 .77 .68 .S9 .SO r ] r //v/oc/chla so so /« zn tie US if iso zs to bo /o /^ 7 to 250 la Hy/o. 9 //S 6 bSO lOB no 10 Si 30 130 iU isz /f 390 30 4- 30 Z2i /3i 41 lO / a4y S43 IZ 37 Figure 19. Graphs of barometric pressure in 1947, 1948, and 1949. Valley on September 19 and 20. This included the strongest evening move- ment as well as the greatest morning movement of thrushes yet recorded in Gaspe. Both days were heavily overcast with intermittent rain and easterly winds. Further data on the weather at this time appear below in the consideration of atmospheric pressure. ATMOSPHERIC PRESSURE AND THRUSH MIGRATION Without conceding any influence of atmospheric pressure upon bird mi- gration except indirectly as it controls temperature and winds and thereby humidity, in other words, weather, graphs (Fig. 19) are provided to show. 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 per
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Keywords: ., bookcentury1900, bookcollectionbiodiv, booksubjectnaturalhistory
