212 
THE NATURAL HISTORY 
from the neft, whilft their brood are very young. 
The little ones Toon acquire an attention to neat- 
nels themfelves, and perform that office by put¬ 
ting their tails out at the opening of the neft. 
Martins prefer a north-eaft or north-weft expo- 
fttre for their nefts, that they may not be cracked, 
and injured by the heat of the fun; yet, inftintft 
does not feem to lead them invariably right, for 
fometimes they build in fuch fituations that their 
nefts have been waffned down by rain, and yet 
they perfevere year after year in the fame fitu¬ 
ations. 
Mr. White has feen young Martins that only 
left their nefts on the 226 of October: from this, 
and other obfervations, particularly from having 
traced their evening retirement in October, for 
fever a 1 nights fucceffively, amongft tome low and 
ftunted thrifts, almoft impervious to a dog, and in 
many parts difficult to approach, he fuppofes, 
that part of them, at leaft, muft have a winter 
retreat in this ifland. It is very remarkable too, 
that the numbers which return in the fpring, bear 
little proportion to thofe which withdraw the pre¬ 
ceding winter. Are they deftroyed by their ene¬ 
mies, or do the parents prevent the younger brood 
from fettling in their neighbourhood ? 
Martins 
