Land Birds of Sac County^ Iowa 123 



trending to the northward one spring day. Ordinarily ten to fif- 

 teen are as many as will be seen together at one time. 



Clarke's Nutcracker (Nucifraga colum'biana). 



It is an accidental visitant. There is only one record for the 

 county and fortunately this is authenticated by the specimen 

 which is in the Smith collection. 



Bobolink {Dolichonyx oryzivoriis). 



The bobolink is a common breeder on the borders of all 

 sloughs or in wet pastures where tall bluegrass is found. My first 

 seen dates vary from May 3, 1912, to May 18, 1910. Along in late 

 July and August the plumage of the male changes to resemble that 

 of the female, but is much brighter and more yellowish than is 

 the plumage of the female in spring. The bobolinks then leave 

 the pasturage or hayflelds where they nested and congregate iti 

 flocks among the reeds or tall grass bordering lakes or sloughs. 

 My last seen dates are from September 3 to October 10. 



Cowbird (Molothrus ater ater). 



Specimen in the Smith collection. The cowbird is a common 

 breeder. I have frequently found its eggs in the nests of yellow 

 warblers, and once each in a wood thrush's nest and a goldfinch's 

 nest. It has been my experience that the yellow warbler always 

 deserts its nest when a cowbird's egg is removed from it. After 

 the nesting season the cowbirds leave the vicinity of the groves, 

 and gathering in small flocks frequent pastures and similar places, 

 but not being found about cattle as much as their name would in- 

 dicate. 



Yellow-headed Blackbird {Xanthoceplialus xanthocephalus). 



This bird is an irregular migrant, being common some years 

 and rare in others. In the spring migration they sometimes fly in 

 pure flocks and at other times in mixed flocks with redwings and 

 grackles. 



As a breeder, it is found in sloughs where very tall grasses such 

 as reed canary grass grow in standing water. It nests in the 

 " Goosepond " when this depression is full of water in summer. It 

 formerly nested at a small pond north of Carnavon. My first seen 

 dates in spring range from April 15 to May 3. 



Red-winged Black-bird (Agclaius pJioenieiis) . 



An abundant migrant, a common breeder, and an occasional 

 winter visitant. I have winter dates of January 21, 1908; January 

 4, 1913; January 27, 1914; February 19, 1915. It usually arrives 

 from March 4 to March 30. The birds continue in flocks for some 

 weeks, not beginning nesting until the season's growth in the 

 sloughs has attained considerable size. I have found its nests 



