61 



March 19, but this is unusually early, the normal date being the last 

 few days of March. 



The first arrivals for 1910 — two birds — came to my houses March 

 28, but up to April 8 only ten birds had appeared. Weather unfavor- 

 able for returning Martins was experienced during the latter half of 

 April, and May 1st arrived before the full percentage of my adult birds 

 had returned . About this time I observed the first signs of nest build- 

 ing, but these operations were stopped on May 3rd, when a cold north- 

 east wind brought us a chilly atmosphere with frequent rains, housing 

 the martins and preventing them from procuring food. 



This cold wave terminated in freezing and killing frosts on 6th, 

 7th and 8th, since which time up to May 17th we had only two or 

 three days suitable for nest building, and on these days the famished 

 birds were compelled to forage for food, for at other times the days 

 were wet and cold, driving insects to cover. 



Up to May 20 no immature Martins, or young of the previous 

 year, had appeared at my Martin houses. The return of the im- 

 mature birds is an important factor in establishing a new colony, for 

 they are driven away from a crowded house by the older birds and 

 must find nesting quarters elsewhere. As a rule these young birds 

 follow the migration of the adults two or three weeks later in 

 their return from the South, but are usually on hand by the last of 

 April. 



The first individuals of last year's broods arrived on the 21st of 

 May — four birds. The bulk of these immature birds were very late 

 in arriving, and only a few of them attempted to nest at all. 



From my records of May 24th, I see that very few of my adult 

 birds had finished their nests, and no eggs had been deposited up to 

 that date. In favorable seasons most of the adult birds have deposited 

 their eggs by this time.* 



From early summer correspondence I learn that generally, un- 



*Notably in 1906, thirty nests contained eggs on May 24th, one set containing highly 

 incubated eggs; and on May 25th, 1903, thirty-seven nests contained eggs. However, 

 this is the year in which a few days cold, wet period, at hatching time in June, killed all 

 the young and three old birds at my colonies. (See Gleanings No. 5, page 41 and plate 

 XI.) 



The next year, 1904, the count was made ten days later, June 3rd, when thirty-one 

 nests were found to contain eggs. On the 22nd of May, 1905, only eight nests contained 

 eggs, while fifty nests were undergoing construction. 



