218 BULLETIN 146;, UNITED STATES NATIONAL, MUSEUM 



Migration occurs both by day and by night. Flock after flock 

 may be seen on favorable days flying north along a beach, and the 

 distinctive calls of the bird may be heard at night. I have recog- 

 nized them clearly on a foggy May night when the birds were passing 

 over the city of Boston. There are also records of the striking of 

 lighthouses by these plover during the night. 



It is evident that late migrants flying north in the spring must 

 be late in returning, if they rear families, while those that return 

 early in July must have been the earl}^ ones to migrate north. On 

 July 30, 1918, 1 saw three semipalmated plover flying north along the 

 shore at Ipswich. They were in full cry, and I wondered whether 

 they were very late spring migrants or early autumn migrants tempo- 

 rarily turning back, or sterile birds that had no interest in the 

 breeding grounds. 



Courtship. — In the latter part of May and early in June on the 

 southern Labrador coast I have seen this brid flying about in circles 

 uttering its loud and rapidly repeated courtship song. The song, 

 which is entirely unlike the call note, may be heard, and the court- 

 ship performance watched, not only in the spring but in the autumn 

 migrations, for there is a recrudescence of the amatory instinct at 

 this season in most birds. The song, if such it may be called, is 

 then generally given from the ground and may be likened to a 

 whinny or to the sound of a bouncing ball. The notes are at first 

 slowly repeated, but the speed increases until the notes follow one 

 another so rapidly that they nearly run together. The birds that 

 utter this song crouch low with tails spread and slightly cocked, 

 wings partly open, and feathers, particularly of the breast and flanks, 

 puffed out. Sometimes one walks in this way around another, some- 

 times two face each other, crouched motionless and then spring at 

 each other and up into the air like fighting cocks. Sometimes one 

 runs after another which, on taking flight is followed by the first, 

 but the most amusing form of this courtship is where two, thus 

 flattened, spread, and puffed, walk slowly side by side as if they 

 were doing a cakewalk, all the time uttering their clucking song. 



H. S. Swarth communicates the following notes regarding court- 

 ship seen in northwestern British Columbia : " On as late a date 

 as June 25 a male bird was seen going through with the mating 

 antics, following the female about with head lowered and breast 

 puffed out to an absurd degree, uttering frequently a low call note." 



Nesting. — A mere depression in the sand without lining or with 

 only a few bits of shells or grass generally constitutes the nest of this 

 species. P. B. Philipp (1925), writing of his experience in the 

 Magdalens, says: "A nest as such is not constructed. A shallow 

 hollow is scratched in the sand, and this is lined with bits of dead 

 eel-frrass, or a hollow is scratched in a bunch of dead seaweed." 



