FAMILY GAVIIDil':. LOONS. 27 



FAMILY QAVIID/E. 



Loons. 



■!\VW^^^ Toes, four; front toes, palmate (full webbed) ; bill, pointed; 



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



* Group 1. Wing, 9.50 to 1 1 inches long. 



Back, with white spots ; tlirout, white or whitish (iminutiiri> or winter). 



(favia Jninnif. Red=throated Loon. 



See Xo. 7. 



Bael<, witliout disliuct white spots; tlie featliers, edged witli asli)-; lliro.-it, wliit<> or 

 dusk}' (^imirmture or wiuter). Gavia urctinis. Black=throated Loon. 



See Xo. (i. 



Head, asliy gray ; tliroat, hlaeli (adult). Gavi'a arrtims. Black=throated Loon. 



See Xo. C. 

 Throat, gray; front of neclv, cliestuiit lirown (adult). 



« irania himmi'. Red=throated Loon. 



See Xo. 7. 



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

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



ITe.ad, black (adult). Gavia iinhi-r. Loon. 



See Xo. .T. 



Top of head, grayish; throat, white (iiiin\atui-e or winter i>lumage). 



Gavin iiiiher. Loon. 

 See Xi>. 5. 



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



Head, ash gray; throat, black (adult). Gavia arcticus. Black=throated Loon. 



See Xo. li. 



Throat, gray; front of neck, chestnut brown (ailult). 



Gavia Inmm.r. Red-throated Loon. 



See X^o. 7. 



* For directions tor measurement, see jinge 0. 



