60 



THE OOLOGIST 



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Tfie ©«roijtst 



FOURTH PUBLICATION TEAR. 



MARCH, 1879. 



SUBJECTS OOLOGIOALLY CONSIDEEED. 



//. CONFIDENCE AND ADAPT- 

 ATION. 



T^HERE is a remarkably close relation of 

 the confidence displayed by birds, with 

 the adaptation of varions places to the re- 

 quirements of nest-building ; and we are 

 i'requeutly obliged to consider both togeth- 

 «M- as inseparable. Whether a certain pair 

 of birds act out of desire ibr protection, for 

 advantage in situation, or in some cases, 

 from compulsion, there is shown in an un- 

 usual placing of the nest in proximity to 

 populated districts, houses, or window-sills, 

 a perception of the advantage thus to be 

 gained, which we might do well to term, 

 accommodatio covfidentia nata. Good ex- 

 amples of this fact are brought to our no- 

 tice every year, in the case of the semi-do- 

 mesticated birds which frequent our lawns 

 and gardens in the summer season ; but as 

 such, and being accustomed to turning to 

 good account all manner of positions for 

 their nests, we are tempted to, and gener- 

 ally do, look upon these little anomalies 

 with a small degree of interest. The very 

 fact of the semi-domestication of a species 

 is an obstacle in the way of the interest and 

 attention a case of adaptation to circum- 

 stances should call forth ; but the moment 

 we become aware of any unusual freak, as 

 exhibited by what we may here term with 



propriety, wild birds, in the selection of a 

 nesting place, we at once exert ourselves to- 

 ward the explanation of the phenomenon. 

 We may be pardoned for want of ardor to 

 a certain extent in some few individual in- 

 stances of adaptation, both of position and 

 material, on account of the })eculiarity of 

 the species to nidificate at all seasons, in all 

 places, and without regard to circumstanes 

 — one nesting place being as usual as an- 

 other. The House Sparrow, for example, 

 is a bird of no choice of material,* we had 

 almost said not even for the frame of its 

 nest, and each disquisition on some new ma- 

 terial used, only renders the succeeding item 

 the more monotonous and disinteresting ; 

 while no one would think of giving partic- 

 ular notice to the position selected, unless 

 the bird be so far uncharacteristic as to 

 place the nest upon the ground or in unin- 

 habited districts. 



Many circumstances may combine to im- 

 press a bird with confidence in man, and 

 the same circumstances often operate in the 

 adaptation of peculiar and actually unfavor- 

 able positions to the whims of birds ; so that 

 it is sometimes puzzliug to determine wheth- 

 er the builders really sought advantage or 

 safety, or exercised a degree of carelessness. 

 We do know, that, notwithstanding the care 

 which birds usually exercise in the selection 

 of nesting places, occasionally in the case of 

 too great confidence tliere will be a surpris- 

 ing disregard for position. We do not look 

 upon tlie nesting of the Chipping Sparrow 

 or Humming Bird within a few inches of 

 the window-sill, as anything extraordinary ; 

 but when a Yellow-winged Sparrow nests 

 within a few feet of a house, and that, too, 

 at disadvantage of position and especially 

 concealment ; and when a pair of Crows, 

 driven and harassed continually in common 

 with others of their tribe by a multitude of 



*In eleven nests of Passer domesticus, there 

 was not a single spccinicu wliieli did not con- 

 tain at least one article of its composition dif- 

 ferent from all tlie rest. Cotton, wool, hair, 

 string, fiower stems, paper, feathers and even 

 bits of wire have been found in nests of tliis 

 bird, besides the two or three usual materials 

 of construction. 



