How a Marsh Hawk Grows 45 



Whatever the diversities of place and material, the dates of nest- 

 finishing and egg-laying seem to be, in this region, remarkably uni- 

 form. Observations covering a dozen nests, and extended over a 

 period embracing the first laying and a rather advanced stage of 

 incubation, have given, as the result of careful calculation, the dates 

 May 10-16 as those within which ( barring sets manifestly belated) 

 the first eggs are invariably laid, — this during four seasons, early 

 and late, which makes it fairly plain that Marsh Hawks stay not for 

 weather. 



Probably the male Hawk does not feed his mate during the 

 incubation period, since the two share the home duties of that 

 season. But it would be most interesting to learn for how long 

 periods they severally sit, and the hours of the day at which they 

 relieve each other. 



How many eggs, at each raising, does the Marsh Hawk lay ? I 

 ask not rhetorically, but for information. With us six eggs is the 

 rule ; sets of five are fairly common, and sets of four are rare. I 

 have found in early June two sets, of two and three, respectively ; 

 these being, manifestly, the "sequelae" of interruption or destruction. 



NEST AND EKrHT EGGS OF MARSH HAWK 



A most exceptional set of eight was found this season in a 50-foot 

 meadow spot, near large willows, on the lowland flats. But even 

 this case would seem to show the evils of over-production. For, of 

 the eight eggs, one was crowded out of the nest and preserved : 

 while from the seven eggs but three chicks were found when the 

 spot was visited two weeks later. Had the three elder birds 

 devoured the four younger ? I have seen a two-thirds-grown Short- 



