TABLE OF CONTENTS. 

 Introductory Note, by Chas. C. Adams. 



ECOLOGICAL PAPERS. 



An Ecological Survey in the Porcupine Mountains and Isle Royale, Michigan, by 



A. G. Ruthven 17 



Introduction 17 



Part I. Porcupine Mountains 19 



1. History 19 



2. Geology 19 



3. General Topography 20 



4. Location of Field Stations 21 



5. The Biota Considered by Stations 22 



6. Summary 40 



7. Interpretations and Conclusions 43 



Part II. Isle Royale 48 



1. General Geography 48 



2. Location of Field Stations 48 



3. The Biota Considered by Stations 48 



4. Summary and Conclusions 52 



Part III. References 53 



The Ecological Distribution of the Birds in the Porcupine Mountains, Michigan 



by Otto McCreary 56 



I The Lake Superior Slope of the First Mountain Ridge 56 



1. Lake Superior (Station I.) 56 



2. Lake Beach (Station I.) 56 



3. Cedar Swamp (Station II. Sub. 1.) 57 



Clearings in the Cedar Swamp 57 



Supplementary Clearing Observations 58 



4. Hemlock Forest (Station II. Sub. 2.) 58 



Supplementary Clearing Observations 58 



5. Hardwood Forest (Station II. Sub. 2.) 58 



6. Camp Clearing (Station II. Sub. 3 and 4.) 59 



7. Mountain Top and Escarpment (Station III. Sub. 1 and 6.) 59 



II. Carp River Valley 60 



1. Carp Lake (Station V. Sub 1 and 3.) 61 



2. Grassy Marshes (Station V. Sub. 2, and Station IV. Sub. 2.) 61 



3. Alders (Station IV. Sub. 2.) 61 



4. Damp Woodland (Station IV. Sub. 3.) 62 



5. Tamarack Swamp (Station IV. Sub. 4.) 62 



6. Carp River (Station IV. Sub. 1.) 62 



7. Dry Woodland (Station IV. Sub. 3.) 62 



a. Western End. . . ■; 63 



b. Eastern End 63 



III. Hardwood Forest South of Carp River (Station VI.) 63 



IV. Little Carp River Valley - 63 



1. Little Carp Lake (Station VII. Sub. 1.) 63 



2. Beaver meadow (Station VII. Sub. 2 and 3.) 64 



V. Summary 64 



1. Water Birds. 64 



2. Birds Frequenting Shores and Banks of Streams 65 



3. Birds found in Grassy Marshes and Alders 65 



4. Birds Frequenting Tamarack Swamps and Cedar Swamps 66 



5. Birds Frequenting Hemlocks and Maples 66 



6. Birds Frequenting the Cliff and Mountain Top 67 



