Bird Architecture 



they forsake their old nesting sites to build in chim- 

 neys that the name chimney swift is now universally 

 applied to them. (They are not swallows ; not even 

 related to them, however frequently one hears them 

 miscalled chimney swallows.) At the nesting season 

 the saliva glands become much enlarged and with 

 the mucilage-like fluid flowing from them the birds 

 glue their wicker cradle together and hang it on 

 the bricks inside of the chimney. The mucilag- 

 inous nest of our swift's Asiatic relative is much 

 sought by Chinese epicures. 



We now speak of house wrens as if it had 

 always been the habit of these friendly little birds 

 to live under the 

 eaves of our houses 

 or in the boxes- set 

 up for them about 

 the home grounds ; 

 but, before there 

 were houses on this 

 continent they, too, 

 nested in tree hol- 

 lows and do still when 

 a satisfactory natural 

 shelter can be found. 



The exquisitely 

 beautiful little wood- 

 duck, cousin of the 

 Chinese Mandarin 

 duck, likewise shows 



Wrens formerly nested in tree hollows 



remarkable indepen- 

 dence to nest in a hollow tree while nearly all her 

 relatives place their eggs either on the ground, in a 



51 



