The Xantus Murrelet 
they will crawl under thick vegetation to lay, if their other requirements 
can there be met. 
The Xantus Murrelets have many nesting characteristics which are 
worthy of note, or 
which, not fully under¬ 
stood, have given rise to 
many errors in bird 
books. They are decid¬ 
edly gregarious in their 
breeding sites. For ex¬ 
ample, on the Coronado 
Islands, just below the 
Mexican border, there 
are three well defined 
colonies on South Island. 
Yet five miles away, on 
North Island, which 
swarms with C a s s i n 
Auklets, gulls, pelicans, 
and cormorants, no 
Murrelet’s nest has ever 
been discovered. 
The individual 
birds of most species 
nesting in this manner 
will lay almost at the 
same time. Not so the Xantus Aflurrelet. On any day in the late spring 
or early summer eggs exist in every state of incubation. I have obtained 
from the original data blanks of Mr. Nelson Carpenter, making due allow¬ 
ance for condition, proof that in one of the colonies referred to on South 
Island there have been eggs continuously from the earliest part of April 
to the twentieth of July,—a period of over three and a half months. 
On May first of this year (1921) I examined nests containing a downy 
young, sets of half incubated eggs, of fresh eggs, of eggs on the point of 
pipping, besides numerous shells the conditions of whose membrane 
showed that they had hatched this spring. 
This disposes of the theory of two distinct nesting seasons. These 
birds are merely following individual idiosyncracies in their nesting dates. 
They do not at any time congregate in Hocks; when found in groups larger 
than three or four, it is merely a matter of accident. So when they come 
to their breeding grounds, they do so independently of each other. The 
result is violent fluctuations from year to year, and a season which, while 
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