IOWA ORNITHOLOGIST. 



6l 



cause ot this change is an un- 

 solved problem though probably 

 connected with some variation of 

 food supply. It is one of the 

 largest and most beautiful of the 

 Warblers, richly though not bril- 

 liantly colored. Usually found 

 on the ground in swampy places 

 or near stagnant pools. 



Dendroica aestiva (Yellow War- 

 bler. ) This is the most familiar 

 of the whole group. It breeds 

 abundantly about farm-houses 

 in towns, and in fact in every lo- 

 cality where bushes and small 

 trees are to be found. Its bril- 

 liant coloring and lively and quar- 

 relsome disposition makes it very 

 conspicuous. No description of 

 the habits of a species so well 

 known is necessary. 



Dendroica cserulescens (Black- 

 throated Blue Warbler.) This 

 can not be considered as one of 

 our common Warblers though 

 in many localities it is far from 

 rare during migration. In ap- 

 pearance it is very striking, differ- 

 ing from all the other members 

 of the family in being all in solid 

 colors, sharply defined. Though 

 dressed in somber tints, it is, 

 with two or three exceptions, our 

 most beautiful Warbler. No- 

 thing can surpass the exquisite 

 effect of the jet black of the 

 throat, verging sharply on the 



snow white of the under parts 

 and clear deep blue of the upper, 

 together with the beautifully 

 banded tail. It is somewhat 

 slow in its movements and is 

 commonly to be seen on the 

 ground or among the lower 

 branches of trees. 



Dendroia coronata (Yellow- 

 rumped Warbler.) Our most 

 abundant species, coming every 

 spring in countless thousands, 

 often before the snow is entirely 

 gone; indeed it has been known 

 to endure a temperature of 20° 

 below zero without apparent in- 

 convenience. It is not strictly 

 insectivorous, but often subsists 

 for a long period upon berries. 

 The habits of the Yellow-rump are 

 too familiar to need discussion. It 

 is an interesting fact that in mi- 

 gration the females usually ap- 

 pear several days before the males. 

 They pass far north to breed. 



Dendroica Maculosa. (Magno- 

 lia 'Warbler: Black and Yellow 

 Warbler.) This elegant and 

 and graceful bird is one of the 

 showiest of his kind. They are 

 seldom seen in great numbers, but 

 are very conspicuous on account 

 of their bright coloring, lively 

 movements and habit ot keeping 

 among the low branches of trees 

 in orchards and near houses. The 

 range of this bird does not extend 



