OF EASTERN PENNSYLVANIA. 155 



there is an accumulation of dry leaves, is wisely 

 selected for building-purposes. 



Nidification does not usually take place until 

 three or four weeks after the arrival of the species, 

 which is often during the latter part of May, but 

 not later than the begining of June; the period 

 apparently depending upon the forwardness or 

 backwardness of the season. Unlike the Redstart, 

 the w r orkis the joint labor of the sexes, and is prose- 

 ecuted with remarkable diligence until completion. 

 At the ordinary rate of working, a nest is five days 

 in building. But little time is lost preparatory to 

 oviposition. This requires from four to six days, 

 and is dependent upon the number of eggs which 

 is daily deposited, and proceeds at the rate of one 

 egg/<?r diem. Incubation takes place on the day of 

 deposit of the last egg, or the succeeding day, 

 most generally the latter, and continues for a 

 period not exceeding lodays. The duty devolves 

 exclusively upon the female. While she is thus 

 engaged, the male actuated by the purest affection 

 administers to her. necessities with the most com- 

 mendable zeal and alacrity. 



When not thus employed he remains in the im- 

 mediate neighborhood ready to resist any attack 

 which may be made upon the nest. On the ap- 

 proach of human beings he evinces the utmost 

 restlessness and solicitude, and seeks by the most 

 pitiful cries to withdraw the intruder from any con- 

 templated assault. 



The young are objects of the tenderest care. 



