ECOLOGY OF ISLE ROY ALE. 3' 7 



Stations:. Kock Harbor, Light-house peninsula, I. 

 Siskowit Bay, V, 1. 

 Washington Harbor, clearing, I, '04. 



Resident: July 6 to September 1. 



First seen July 6 as it was passing over the Eock Harbor light-house. 

 It appeared to be rare in this locality. On August 10, 11, 14, it was 

 also observed at Siskowit, but was rare here also. At Washington Har- 

 bor it was very common, feeding either singly or in pairs or small flocks 

 in all the clearings. Much of the food was taken on the wing, but 

 grasshoppers were greatly relished, and these the birds pursued on the 

 ground. There is little doubt but that these birds breed here in the 

 clearings, but owing to tlie lateness of the season, no nests were found. 

 I see no reason why these birds should not be found more plentiful 

 at the other localities unless the clearings are hardly extensive enough 

 to furnish the conditions best suited to them. Insect food seemed 

 abundant everywhere on the island, so it seems that clearings were what 

 was lacking. The birds commenced their migration towards night, and 

 a little after sunset large flocks would be seen drifting slowly toward 

 the south, catching their evening meal while on the ■^'ay. 



43. Chaetura pekigica (423) . Chimney Swift. 



Range. — Eastern North America north to Labrador and the fur 

 countries, west to the Plains, and passing south of the United State's, 

 in winter, at least to Jalapa, Mexico and Cozumul Island. 



Stations : Rock Harbor, I. Washington Harbor clearings, I, '04. 



Resident: July 8 to August 10. 



These birds were only occasionally seen at Rock Harbor, commenc- 

 ing with July 8. On August 1 it was found at Siskowit and the light- 

 house keeper on Menagerie Island said that two pairs of these swifts 

 nested in the chimney of the light-house, but he thought they had left 

 about the first of August. At Washington Harbor, on August 19 a 

 pair of these birds was observed circling over the clearings and near- 

 by river, just at sunset. These were the only ones observed here either 

 year. 



Isle Royale being wooded for the most part with conifers and having 

 very few buildings upon it, the cavities used by chimney swifts for 

 nesting places are of course almost wanting. Conifers rarely offer any 

 cavities except where the Avoodpeckers have dug out their burrows in 

 the dead trunks so common in old burnings. Perhaps this is the reason 

 why more were seen at Rock Harbor than at the other localities as 

 at this station there were extensive burnings. Probably as Isle Royale 

 becomes more settled and chimneys and other nesting places become 

 more plentiful the Chimney Swift will become abundant, as it already 

 is in some of the towns on the northern shore of Lake Superior. 



43. Trochiliis coluhris (428). Ruby-throated Humingbird. 



Range: Eastern North America, to the Plains, north to the fur 

 countries, breeding from Florida to Labrador, and south, in winter, 

 to Cuba, Mexico and Veragua. 



Stations : Menagerie Island, V, 10. Washington Harbor clearing, 

 I, '04. 



Resident: August 17 to 22. 



A pair of these birds were seen on August 17 hovering over some 



