THE WILLOW-WRENS OF A LOTHIAN WOOD. 413 



the date of the commencement of building. Egg-laying seems 

 to take place usually from 4 to 6 a.m., the birds leaving their 

 nests again before 9 o'clock. There are exceptions, however. 

 For instance, one bird (No. 18) did not lay her first egg until 

 after 10 a.m. ; the second was deposited before that hour on the 

 succeeding day; and the third between 10 and 11 a.m. on the 

 third day. One egg is laid each day. As the eggs increase in 

 number the birds begin to sit for longer periods, and incubation 

 may commence before the full clutch is deposited. In this 

 respect there is great variation, some birds incubating from the 

 fourth or fifth egg, others waiting until the clutch is complete, 

 and, exceptionally, even a day longer. The hatching of the 

 young, consequently, may extend over a day or two. 



During the laying of the eggs, and before incubation has 

 commenced, the male continues to pay considerable, though 

 intermittent, attention to the female. His behaviour, however, 

 undergoes some slight modification. His excitement decreases, 

 he becomes more sedentary, and his song, although still low in 

 tone, is uttered more frequently and is unusually prolonged, the 

 "cheep" note being almost invariably interpolated. On the 

 female going on to lay, he escorts her to the nest, and then, 

 deprived of her stimulating presence, he shows a tendency to 

 revert to his old habits of the period previous to her arrival. 

 He returns to his old "song-centre" and resumes his customary 

 mode of life ; the song becomes louder and more normal, the 

 " cheep " note being comparatively little uttered. This note, 

 however, persists with some males throughout the summer; the 

 mental attitude underlying it is difficult to appreciate. 



With the commencement of incubation, the third stage in 

 the male's year, already foreshadowed during laying-time, comes 

 into being. The habits of this period are largely a repetition of 

 those of the first. The " song-centre " regains its ascendency, 

 and from that point of vantage the old excursions round the area 

 recommence, varied by indeterminate tussles with other males. 

 I have not observed them feed their mates during incubation ; 

 they may do so exceptionally, however, since I have seen them 

 carry food to the female as she sat brooding newly hatched 

 young. (It is in fact dangerous to generalize ; no two birds 

 behave exactly alike throughout the season.) They rarely go 



