736 MICHIGAN BIRD LIFE. 



APPENDIX 2. 



HYPOTHETICAL LIST. 



This list includes species which have been iittribvitcd to Michigan but whose status, for 

 one I'eason or anotlier, is doubtful. 



Western Grebe. ^Echmophorus occidentalis (Lawr.). (1) 



A western species, breeding from Britisli Columbia to northern California, 

 and from Saskatchewan to North Dakota, and stragghng eastward ac- 

 cidentally as far as Minnesota and Wisconsin. In spite of numerous 

 references to this species we have failed to find a single good record for 

 Michigan. Holboclls Grebe seems to have been mistaken for this species 

 quite generally, but with little excuse. The fact that the neck of the 

 Western Grebe is nearly or quite as long as the body, and the culmen 

 always more than 2h inches long separates it sharply from any other grebe. 



Eared Grebe. Colymbus nigricollis calif ornicus {Ilecrmann). (4) 



This is another western species which sometimes strays eastward as 

 far as the Mississippi, and casually even farther. It has been reported 

 several times from Michigan, but we have been unable to verify a single 

 instance. There is a genuine specimen in the University of Michigan 

 Museum at Ann Arbor, said to have been taken in the vicinity, but the 

 data are open to so much cj[uestion that the specimen must be ignored. 

 Mr. Norman A. Wood writes that another specimen was taken at Saline, 

 Washtenaw county, January 10, 1879, by WiUiam Minett. We have not 

 been able to verify the determination of this specimen, or even to make 

 sure that it is still in existence. Butler records two specimens for Indiana 

 and there are sevei'al others from eastern points. In winter plumage, 

 our common Horned Grebe might be mistaken easily for this species, 

 but the shape of the bill is diagnostic. See key to species of grebes, page 

 36 of this volume. 



Black-throated Loon. Gavia arctica {Linn.). (9) 

 Synonyms: Black-throated Diver; Arctic Loon. 



Smaller than the common Loon and larger than the Red-throated Loon, 

 this bird is most likely to be confounded with the latter species. Its 

 tarsus, however, measures less than the middle toe without the claw, 

 while in the Red-throat the tarsus measures more than the middle toe 

 and claw. The winter plumage of the three species is so nearly identical 

 that only a careful comparison of proportions and measurements will 

 separate them satisfactorily. 



The present species is a rare winter visitor to the northernmost waters 

 of the United States and probably occurs once in a while on Lakes Superior, 

 Michigan, and Huron. Kneeland includes it in his list of Keweenaw Point 

 birds (1857), and it figures in several of the old hsts. Possibly some 

 of these "records" were based on specimens actually taken, but apparently 



