Migration 27 
when closely approached, the only method whereby an adequate 
knowledge of the details of migration could be obtained would 
be that of extensive collecting and sexing of many birds through 
Several spring and fall seasons. No attempt has been made, as 
yet, in that direction. 
However, some general observations have been made in this 
regard. First of all it seemed evident that the first birds that 
arrived, both at Evanston, Ill., and at Ithaca, New York, were 
resident males. Though this is not in accord with Allen’s (1911- 
13, p. 77) observation of the Red-winged Blackbird, still it 
seems strongly conclusive in the case of the Prairie Horned Lark 
because of the following facts: (1) the first Larks to arrive at 
Evanston (January 10), were not in flocks but distributed them- 
selves singly (one pair was noted) over the breeding area; (2) 
full ground songs and one typical flight song were noted January 
12 and much fighting was in progress between males. The same 
observations were essentially true at Ithaca, New York, the 
spring of 1927. The first Lark noted at this place was a single 
individual observed by Dr. A. A. Allen, February 3. The first 
Larks appeared on the breeding grounds February 9 and, when 
first observed, were scattered over it singly, singing or indulging 
in aerial combats. 
Resident females are, it appears, the next to arrive. Some of 
them come very shortly after the males. Though Criddle (1917) 
writes that the males precede the females by two weeks at 
Aweme, Manitoba, I believe some females come with the first 
males or very shortly thereafter. What seemed to be a mated 
pair was noted with the first Larks, January 10, 1926, at Evans- 
ton, and several pairs were noted January 16, though unmated 
males seemed to be as numerous as mated on January 23. How- 
ever there were males only on the territory February 5, but two 
days later paired Larks were numerous and mating activities in 
full swing. At Ithaca, New York, 1927, the first birds to appear 
on the breeding grounds (February 9), seemed to be males only 
but a mated pair was noted February 19, as well as one unmated 
Male. : 
Transients or migrants, i. e. birds still in flocks and flying 
over, perhaps to more northerly breeding grounds, are frequently 
noted in late February and in March at Ithaca, New York. Thus 
on March 12, 1916, a flock of one-hundred was noted; similarly, 
