FAMILY PODICIPIIXK. GKEBE8. 25 



WATER BIRDS. 



KEY TO THE SPECIES. 



FAMILY PODICIPID^E. 







Grebes. 



Toes, four ; three in front, one behind, with lobate webs, 



* Group 1. Wing, less than 6.50 inches long. 



Depth of bill at base of culmen, over .40. In summer: Bill, with black baud; throat, 

 black. 



In winter : Bill, without black baud ; throat, white. 



Poclilymbus podiceps. Pied-billed Grebe. Hell Diver. 



See No. 4. 



Depth of bill at base of culmen, less than .40. In summer: Two small tufts of 

 brownish gray or buff-colored feathers behind the eye; crown, nape, and throat, black. 



In winter : Plain colored, without black or buff oil head; upper plumage, grayish black; 

 uuderparts, silvery white, often tinged with ash gray on throat and sides. 



Colymbus auritus Horned Grebe. 

 See No. 2. 



* Group 2. Wing, over 6.50 inches long. 



In summer : Crown, black ; upper throat, gray ; lower throat and breast, chestnut rufous ; 

 rest of underparts, silvery grayish white. 



In winter : No rufous brown on throat or breast. Colymbus hoJba>lli. Holboell's Grebe. 



See No. 1. 



* For directions for measurement, see page 9. 



