obV CIRCUS CYANEUS VAE. HUDSONIUS, MARSH HAWK. 



nest of the Marsh Hawk I ever discovered myself — one that I found at 

 Pembina, Dakota, June 3, 1873. It was on the ground, in the midst of 

 a large patch of wild roses, near the border of the woods along the 

 river. There was no depression of the ground; the cavity of the nest 

 was slight ; its diameter, about twelve inches ; its height, about three 

 inches. The base was a few rose-bush twigs, upon which rested a mass 

 of dried grasses, rather neatly and for the most part circularly dis- 

 posed ; there was no special lining whatever. The eggs are variously 

 rated by writers from three to sis in number. In this instance there 

 were five, slightly incubated at the date mentioned. Four or five ap- 

 pears to be the ordinary number. The eggs are broadly oval, and 

 nearlv equal in contour at both ends. My specimens measured as fol- 

 lows: 1.87 by 1.45; 1.86 by 1.45; 1.82 by 1.44; 1.80 by 1.45; 1.80 by 1.42. 

 They were dull white, with the faintest possible greenish shade; there 

 were no evident spots, but much mechanical soiling. In numerous 

 other specimens I have examined, the bluish or greenish shade is much 

 stronger; and, authors to the contrary notwithstanding, some sets dis- 

 play markings, often pale and obscure it is true, but too evident to be 

 easily overlooked. These consist of irregular surface-markings, in small 

 spots and larger blotches, of pale brown, with other shell-spots of lilac, 

 lavender, or pale neutral tint. In this wide range of variation, eggs 

 from the same nest not seldom differ, though any one clutch is usually 

 much the same throughout. I have seen much smaller eggs than those 

 the measurements of which are above given. 



In the case just given, I had seen the pair of birds for several days, 

 but could not trace them .to their nest; at length, however, T stumbled 

 upon it by accident ; the female was setting, and did not fly up until I 

 was within a few feet of her, my approach being hidden by the bushes. 

 She flew hurriedly away, with loud cries, which soon brought the male; 

 and the pair circled for some minutes overhead. The male was quite 

 shy and perfectly mute ; the female, on the contrary, circled close over- 

 head, and continually uttered a harsh note. I contented mj'self with 

 securing the nest and eggs, not caring to take the life of the devoted 

 mother. The same season I almost constantly saw Marsh Hawks 

 throughout Northern Dakota; they were the most abundant and uni- 

 versally distributed of all the rapacious birds. In July, at Turtle 

 Mountain, several pairs had bred in the vicinity of one of our camps; 

 and on one occasion I secured a family of five, newly on wing — the male 

 alone escaping. Here, as elsewhere, the brown birds are much more 

 numerous than those in blue plumage; in fact, I saw scarcely a dozen 

 of the latter during the whole season. These Ijirds showed little of the 

 wariness most Hawks display, and almost any number could have been 

 secured. The craws of those examined contained insects, especially 

 grasshoppers, with remains of small quadrupeds and reptiles. 



The geographical distribution of the North American Marsh Hawk is 

 coextensive with the continent. In most localities it is one of the most 

 abundant representatives of the family, and may be seen the whole 

 year. But it is, at least partially, migratory; that is to say, the same 

 individuals do not reside permanently in all localities, nor even in those 

 where the bird, as a species, is seen at all seasons. In general, the ma- 

 jority of individuals are bred further north than those places where they 

 reside most of the year ; and the further south we proceed, the fewer 

 birds are found during the summer. In most imrts of British America, 

 over the vast extent of which the bird ranges, it is stated that it is seen 

 during only a portion of the year, when the food supply is assured. 



Digitized by Microsoft® 



