FAMILY GAVIID.E. LOONS. 27 



FAMILY QAVMD/E. 

 Loons. 



^^V^,^,,^ Toes, four; front toes, palmate (full webbed) ; bill, pointed; 



(^^^^> tarsus, flattened ; hind toe, with flap or small lobe. 



* Group I. Wing, 9.50 to 11 inches long. 



Back, with w^hite spots ; throat, white or whicisli (immature or wiutei). 



(iavia Inmmr. Red=throated Loon. 



See No. 7. 



Back, witliout distiuot white spots; tlie feathers, edged with ashy; tliroat, white or 

 dusl^y (immature or wiuter). Gavia urcticus. Black=throated Loon. 



.See No. 0. 



Head, asliy gray; tliroat, black (adult). Gavia arcticus. Black=throated Loon. 



See No. 6. 

 Throat, gray; front of ueck, chestuut ])rown (adult"). 



Gavia lumme. Red=throated Loon. 



See No. 7. 



* Group 2. Wing, 11 to 15 inches long. 

 Section 1. Depth of bill at base, more than .85. 



Head, black (adult). Gama imher. Loon. 



See Xo. 5. 

 Top of head, grayish; throat, white (immature or winter plumage). 



Gavia imber. Loon. 



See No. 5. 



Section 2. Depth of bill at base, less than .85. 



Head, asli gray; throat, black (adult). Gavia arcticus. Black-throated Loon. 



See No. 6. 

 Throat, gray; front of ueck, chestnut browu (adult). 



Gavia lumnie. Red=throated Loon. 



See Xo. 7. 



* For directions for measurement, see page i). 



