41' Iowa Orxitholo(4ist. 



Nearly all the northern species in their southward migration pass into Southern 

 Mexico, Central and South America. Abundance of special kinds of food and 

 otlier favorable conditions in their winter home may have induced indi\'iduals 

 to remain there occasionally throiif^h the year, and so, the habit once formed, 

 migration northward Would {gradually decrease and finally stop altogether. 

 Similarly, individuals of southern forms might have pushed northward by de- 

 grees, led on by favoring conditions, till at last whole species would be induced 

 to migrate and their present range would be reached. Such changes of habitat 

 have gone on even under liuman observation. 



Su(^h seems the most plausible theory of the origin, past movements and 

 present distribution of this most interesting family of birds. Further research 

 and by more experienced students of distribution may give a simpler and more 

 satisfactory solution of the intricate problems here briefly touched upon, as also 

 farther anatomical companions may reveal much that is new and valuable in 

 regard to the relationships before discussed, but for the present we will be com- 

 pelled to I'est on these results of a few somewhat superficial and hasty observa- 

 tions and researches. 



THE P1ED=BILL GREBE— ( Podilymbus podiceps. ) 



BY CARL FRITZ HENNINd. 



THE Pied-bill Grebe, or Hell Diver as it is commonly called, in this locality 

 is known to almost every boy. Arriving here during the first week in 

 April, they remain with us until late in October. When we have an early 

 spring, the dalchick makes his appearance in March. 



In the spring of '94, trees and shrubs were budding by the 9th of March and 

 our friends the Bluebirds wai-bled their notes of joy from the tree-tops. BWhe 

 doth we had a cold snap and on the 2()th a farmer boy brought a Pied-bill Grebe 

 into our store, having captured it that morning in a pond frozen in the ice- 

 making it neccessary for the boy to cut the ice around the Grebe with a knife 

 to release the poor bird from its icy prison. During the spring and fall migra- 

 tions the Pied- bill Grebe are plentiful, hundreds feeding at Clear lake and Cairo 

 lake (Mud lake) in the adjoining counties north. In Boone county, they breed 

 in suitable localities — nearly every large marsliy pond has a pair of these truly 

 beautiful Grebes. 



All the nests that I have found were uniformly formed of partially decayed 

 reeds, rushes and grasses, mixed with mud and debris Ijrouglit iip from the 

 bottom of the pond. The nest is usually fastened to acquatic plants and oftenest 

 placed where the water is deepest, but so well concealed that it is rarely found. 

 The number of eggs in a full set is u.sually seven, rarely nine. In the Iowa Ok- 

 xiTHOLO(ii.sT, Vol. one, page 44, my fellow member John V. Crone .says : "The 

 eggs are almost invariably found covered and incubation most likely proceeds 

 withcmt the aid of the parent bird." My brother ornithologist may liave found 

 more nests of the Pied-bill Grebe than I, but my _ observations differ from his. 

 The eggs that I have found were only partially covered and several nests with 



