EARLY JUNE—OUR LAST EXCURSION 153 
note which sometimes may be raised to a 
‘scream.’ The others only twitter quietly 
as arule, but if the nest be approached the 
notes are louder, even to a scream. All these 
birds will mob an attacking or strange bird, 
such as a hawk, or rook or a crow, in which 
case they become very excited and their 
notes of alarm are shrill and piercing. 
*K ** * * 
It was difficult to distinguish the sombre- 
hued nightingale from similar birds as he 
sat concealed amongst the leaves, but the 
red-brown patch above the tail, seen as he 
flies away from you, is plain. What a power 
of endurance in their long migratory flights, 
which must be kept up for hours at a time, is 
possessed by birds, especially those whose 
flight 1s of the jerky or looping kind, as 
with the long-tailed tit, for example. I 
have seen them at sea ; their method of pro- 
gression over the water is the same as on land. 
It would seem as if these birds required a 
momentary rest between each flutter of the 
