18 



were moving northward may be well called "birds of the first wave," 

 that is, Ducks, Geese, Blackbirds, Meadowlarks, Robins, and Blue- 

 birds. These are the birds with which we have to deal in the study of 

 these seven days. Migration was reported from southern Wisconsin 

 and northern Illinois, against a northeast wind, with the temperature 

 but two or three degrees above freezing, and from east- central Kansas 

 under slightly warmer conditions. It seems likely that some of these 

 notes belong to a warm wave which occurred two days before, but it is 

 also certain that some Ducks and Geese were migrating in the early 

 morning hours, straight against the northerly winds. 



March 19 at 11 p. m. an area of slightly lower pressure had just passed 

 over the Upper Mississippi Valley, and the barometer rose steadily 

 all night. Between Saint Paul and Saint Louis the temperature re- 

 mained the same as the day before; northward it was slightly higher; 

 the winds were light, and were everywhere from KE., NW., and W» 

 The temperature ranged from 45° at Saint Louis to 2J° at Moorhead. 

 The average barometer, at 1L p. m., was 30.07 inches, and at 7 a. m. of 

 the 20th, 30.15 inches. Cloudy weather was reported everywhere ex- 

 cept in the Lake Superior region. In general, the condition may be 

 said to have been very unfavorable for migration, yet new arrivals were 

 still noted from the same places as on the day previous, with the ad- 

 dition of records from southeastern Dakota, eastern Iowa, and south- 

 central Iowa. It would seem that the Ducks and Geese were so desirous 

 of reaching their breeding grounds that they pushed northward in 

 spite of the wind and the clouds, as soon as the temperature rose two 

 or three degrees above freezing, regardless of the fact that the winter's 

 snow still covered the ground, and the lakes and rivers were still bound 

 with ice. Not until a week later did any streams open in the region 

 which was now being invaded by the migrating hosts. 



March 20 was characterized by very high barometer and by a marked 

 advance of the isotherm of 30° to points north of Duluth ami Moor- 

 head. There was no place in the Upper Mississippi Valley at 11 p. m., 

 March 20, where the pressure was less than 30.2, and in western Da- 

 kota it was 30.3. Calm weather or very light north winds prevailed, with 

 clear weather along the Mississippi and the Great Lakes, and cloudy 

 weather with light rains on the Missouri. The minimum tempera- 

 ture at Saint Louis was 43° ; at La Crosse 37°; at Saint Paul 20°, and 

 at Moorhead 23°. It was a moderately fair night for migration. The 

 culmination of the high pressure was reached, and already in the south- 

 ern Rock}' Mountain region the low pressure was developing which 

 was to bring about the immense movements which took place during 

 the next three days ; already the isotherms in that quarter were begin- 

 ning to move northward and the wind along the Gulf coast had changed 

 to SE. The birds seemed to have a foreknowledge of the approaching 

 change, for twice as many ' firsts ? were recorded as during the two 

 previous days. Some of these came from central Missouri, where the 



