THE CANADIAN FIELD-NATURALIST 



VOL. XXXIV. 



FEBRUARY, 1920. 



No. 2 



LAKE-SHORE BIRD MIGRATION AT BEAMSVILLE. ONTARIO. 



By Hamilton M. Laing, Portland, Oregon. 



The following field notes were gathered during 

 the summer and autumn of 1918. While in the ser- 

 vice of the Royal Air Force the writer was sta- 

 tioned upon the south shore of Lake Ontario almost 

 due ncrth of the town of Beamsville. Here in 

 checking the aerial gunnery practice six or seven 

 hours were spent daily up in a fifty-foot tower at 

 the water's edge. Periods on duty ranged from 

 daylight until dark. As every day was spent large- 

 ly out-of-doors and duty commenced on alternate 

 mornings at dawn, excellent opportunity for obser- 

 vation was afforded. A rough bird census was 

 taken daily and new migrants and disappearances 

 thus noted. 



The country surrounding the tower and within 

 range of the field glasses consisted of the open lake 

 northward, and to the south stretched a flat typicdlly 

 peninsular farming land of fields and orchards in- 

 terspersed with remnant wood lots. Most of the 

 notes were gathered from the tower; unless other- 

 wise stated, each record following may be so taken. 

 A few birds were noted in the woods to southward 

 that did not show themselves close to the water. 



The course of migration here was from cast to 

 west. A great many birds followed the shore and 

 it was plain very early in the season that this was a 

 pathway. Many expected species, however, not- 

 ably the hawks, were disappointments, and the fol- 

 lowing gleanings may be as noteworthy for their 

 omissions as their records. Nearly all migrants 

 chose the fine days for moving and almost invariably 

 passed during the early morning hours, or before 

 9 a.m. There was little movement in the after- 

 noon. The bobolinks, bluebirds, blackbirds, snow- 

 flakes, horned larks, waxwings, pipits and swallows 

 made a procession of it here; other species were 

 more retiring and veiled their movements. Birds 

 not mentioned in the following list were not seen in 

 the autumn. No specimens were taken. Where any 

 doubt existed in the mind of the writer, the record is 

 marked so (?). The number in italics after the 

 date gives the number of birds seen. The last notes 

 were made November 26. 



Colymbus auriius, Horned Grebe. Oct. 5, first 

 noted; small company. Oct. 13, hundreds occupy- 

 ing waters near shore for several miles. They be- 

 came quite callous to machine-gun fire and were 

 very numerous till the end of the month. Only on 

 rare occasions was one of these divers noted in 

 flight. Numbers declined as follows: Nov. 6 (50); 

 Nov. 8 (50); Nov. 16 (1); Nov. 18 (few); Nov. 

 26 (1). 



Cavia imber. Loon. Aug. 10 (1); Aug. 20 (1); 

 Sept. 30 (1). During October seen almost daily 

 and often in flight. Nov. 1 (2 in flight) ; Nov. 6 

 (young); Nov. II (1); Nov. 19 (one flying high 

 south-east across the peninsula). 



Icarus argeniatus, Herring Gull. Aug. 1 7 (6) ? 

 Owing to the difficulty in distinguishing this from 

 the next species, no exact record could be kept. 



Argentatus was noted in September and October 

 but very sparingly, and in November the numbers 

 rose and fell apparently with the weather. Nov. 

 4 (numerous) ; Nov. 7 (beautiful adult picked up 

 on shore) ; Nov. 20 (numerous) ; Nov. 26 (adult 

 and young). 



Larus delcnmrcnsis. Ring-billed Gull. Much 

 more common than the preceding species up till 

 November. July 21, July 28. Sept. 26. Oct. 13, 

 Oct. 17. Oct. 19 (young); Oct. 23, 26 and 29 

 (numerous); Nov. 10. 



Lotus Philadelphia, Bonaparte's Gull. Oct. 13 

 (flock); Oct. 17. Oct. 31. Nov. 1 (flock). Ob- 

 served also Nov. 2, 3. 4. 6. 7. 10 and 18. Unlike 

 the larger gulls, this bird almost invariably was post- 

 ing west close to shore. 



Sterna caspia, Caspian Tern. Sept. 4 (3) ; 

 Sept. 25 (2). One of these birds in the first in- 

 stance and both in the second were travelling east 

 fairly close to shore. 



Sterna hirundo. Common Tern. Aug. 19 (12); 

 Aug. 22 (3); Aug. 25 (2); Sept. 6 (flock); SepL 

 17 (11); OcL 1 (20); Oct. 2 (three flocks). In 

 nearly all cases moving westward, low. 



Phalacrocorax dilophus. Double-crested Cormor- 

 ant. On Nov. 21. 23 and 24, a lone bird, doubt- 



