BEHAVIOUR OF A FLY-CATCHER. 229 



herself; her excursions are, however, as brief as 

 possible, and, the food obtained, she flies back to 

 her absorbing occupation. It appears that in many 

 cases the conduct of birds in this respect is much 

 influenced by the state of the weather; if it is 

 raining, blustering, and cold, we may be sure to find 

 her at home, protecting her treasure from the in- 

 jurious effects of such a state of the skies ; if, 

 however, it is clear, genial, and warm, the bird, 

 which, in the former case, would only absent her- 

 self, when at all, for a few minutes, apparently 

 sensible that exposure will not injure her eggs, 

 frequently leaves them for an hour or more ; the 

 exercise, and food, and change, being both neces^ 

 sary and beneficial to herself. 



An interesting account of the behaviour of a 

 fly-catcher during incubation, narrated by a friend 

 of Mr. Jesse, shows that birds are unquestionably, 

 in some degree, observers of meteorological pheno- 

 mena, although the temperature of the atmosphere 

 in this instance was artificial. This bird had built 

 its nest in his conservatory for several successive 

 years. It was observed that it invariably quitted 

 its eggs, whenever the thermometer was above 71 

 or 72, and resumed her place upon the nest when 



