ECOLOGY OF ISLE ROY ALE. 89 



3. Bitli-tish Zone and Delta (Citation III. 3). 



Tliis small grass and sedge covered marsli was too smiall to attract 

 many marsh birds, and a pair of R«amp Sparrows with, two young, a 

 pair of Kingfishers and Song Sparrows, a Red-winged Blackbird and the 

 Lesser Yellow Legs Avere the only birds observed here. The last two 

 were only observed once, and no doubt they were only stragglers here. 



This small marsh was surrounded by a forest of spruce, birch and 

 balsam, and here the Golden-crowned Kinglet, Magnolia Warbler, Chick- 

 adee and Red-breasted Nuthatch wei'e found. 



//. Trail to Humnrr Lal-e {mation III, J-i). 



Starting from the harbor this trail first went up a hill through a 

 birch forest, then across a narrow cedar swamp into a birch, spruce 

 and balsam forest and down the hill to Sumner Lake. As the birds found 

 in the birch forest were not the same as those found in the birch, spruce 

 and balsam forest, the habitats will be distinguished. The cedar swamp 

 was too small to be of any importance, and the birds in it were nearly 

 the same as in the birch, spruce and balsam forest of which it will be 

 considered a -part. 



a. Birch Forest. 



Judging from what had been observed before these birch woods were 

 visited, I expected to find the Oven Bird and Red-eyed Vireo, and upon 

 investigation, many of both kinds were found. A family of Black-throated 

 Grreen Warblers were also seen. Several Cedar ^'S'axwings and White- 

 throated Sparrows were observed along the edge of Rock Harbor near 

 the trail, but they occurred almost everywhere along the edge of the 

 Harbor irrespective of the kind of trees. In rowing along the shore 

 these birds were seen very much more often than any other. 



l). Birch and Coniferous Forest. 



This habitat was frequented by the Chickadee, Golden-crowned King- 

 let, and Red-breasted Nuthatch, the three most common birds in all the 

 coniferous forests that were visited. The Winter Wren was heard 

 in the cedar swamp. 



5. Sumner Lalce (Station III. 5). 



This habitat included Sumner Lake and the grassy marsh whicb sur- 

 rounded it. Everywhere in the marsh the ground was soft, and the 

 thick mat of grass sank under the weight of the body until the water 

 poured into the shoe tops. The line dividing the grass and sedges from 

 the forest was very distinct, but there were several stunted tamairacks 

 and alders growing out in the marsh (Figs. 18-23). 



Many White-throated Sparrows were heard in the forest near the 

 marsh, and at the foot of one of the alder bushes near the edge a nest 

 was found hidden in a bunch of grass growing around the bush. Here 

 in a well built nest of grass were two nearly fledged young (July 18). 

 On the same day another nest of this bird was found on the other side 

 of the lake, in a position similar to the one described above, but instead 

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