166 Bird-Song : and New Zealand Song Birds 
as the sun was dipping into the sea, an old cock uttered a 
strident call and shot straight into the air, followed by an in¬ 
calculable feathered multitude. Higher and higher rose the 
host until it was but a stain in the sky. At this stupendous 
altitude—in a moment of time as it seemed—the leader shaped 
his course due north and the stain melted into the night.... 
In this manner and for ten days, flocks of kuaka continue to 
arrive at and depart from Spirits Bay. With the coming 
of August—having meanwhile reared its brood—it begins the 
voyage to its Southern home. As the young birds are at that 
time incapable of an extended flight, it returns much more 
leisurely than it went. The spring sunshine of October 
welcomes the wanderer home to Te Reinga.’ ’ The depar¬ 
ture described took place in April, the destination and breeding 
place of the birds being the coasts of Siberia. It is a curious 
fact that Spirits Bay is also the point of departure for the souls 
of the Maori dead. Here they descend into the sea by means of 
roots of a pohutukawa, and proceed under water to their 
unforgotten fatherland. 
It is known that, in clear weather, migrating birds fly at a 
great elevation—between one and two miles. The reason for 
this is not known. One surmise is that the bird keeps two land- 
surfaces in sight; the one it is leaving, and the one it is making; 
but this cannot be correct, since a great deal of migration takes 
place during the night; and the New Zealand cuckoo, in order 
to be able to keep two land surfaces in sight, would be com¬ 
pelled to ascend approximately thirty miles. Another surmise 
is that it is less tiring flying in the cooler upper air; but against 
this is the fact that the rarer atmosphere makes effort more 
laborious. Another is that the air-currents may be more favour¬ 
able in the upper strata; and there may be reason for this sur¬ 
mise. At any rate, the cuckoo usually arrives in New Zealand 
with a northerly wind, more generally towards the middle or 
end of September, though its appearance earlier has often 
been recorded. Taylor writes (TI, p. 406) that their first feeble 
cry may be heard in August. It leaves about February, though 
occasional birds have been seen as late as April. 
