Oct.-Deo. 1921.] 



The Canadian Field-Naturalist 



139 



out the ration. This trait imdouhtedly 

 extends tlie usefulness of each species of 

 birds and at the same time explains why. 

 in time of great insect plagues, birds are 

 not engaged in eating them to the ex- 

 clusion of less abundant food. Some va- 

 riety' is desirable if not an absolute ne- 

 cessity to them. 



The quickness of some of Falco's reac- 

 tions were remarkable. An extreme ex- 

 ample can be presented. She slept on 

 the top of her cage, canary-like, with 

 her head under her wing as it is generally 

 de.'*cril)ed, although really the head is 

 hidden under the interscapular feathers 

 between the shoulders. 



Wishing to obtain a photograph of her 

 in this attitude a camera was set con- 

 veniently, and late at night, when she 

 was sound asleep, an explosive magnesium 

 flash was fired. Of course she awoke im- 

 mediately, but the speed of her movement 

 was only appreciated when the resultant 

 negative was developed. It presented two 

 clear superimposed images without blur 

 between. One showed iier asleep with 

 only a slight depression in the feather 

 masses where the head was hidden ; in 

 the other she was wide awake regard- 

 ing the light. What the duration of the 

 flash was I had no means of telling ; it 

 was surel}' but a small fraction of a sec- 

 ond, yet during^ this short period she 

 had held her pose long enough to make 

 a sensible impression on the plate. She 

 had awakened, changed her position so 

 quickly that the movement made no blur, 

 and again held her position long enough 

 to register another picture. 



Falco had the habit of "caching" super- 

 fluous food. She did this from the first, 

 and in so business-like and natural a 

 manner that I am convinced that it was 

 instinctive and is a regular specific habit. 

 I have seen no suggestion to this in the 

 literature relating to the wild bird. This 

 case may not prove bej'ond question that 

 wild Sparrow Hawks do hide stores, but it 

 is strongly suggestive of its probability 

 When hunger M'as temporarily satisfied, 

 tlie unconsumed remainder of the supplies 

 was invariably carried in the bill to one 

 of several usual hiding places. The most 

 favored one was on top of the electric 

 meter on the wall nearby. She would 

 place the valued bit in the depression be- 



tween the top of the meter and the wall, 

 and stamp it down with her feet in a 

 business-like manner, churring with a note 

 of exultation and then withdrawing to 

 view results. If not satisfied she would 

 return and rearrange and hammer il 

 again and when satisfied seek her perch 

 Any time thereafter a motion on our pari 

 towards her store would arouse anxious 

 interest, and if the threatened theft were 

 pressed she was immediately on hand to 

 protect her property. Even if the attempi 



a. 



a. Normal falcon bill. 



b. Overgrown falcon bill, showing' tendency of 

 grrowth and loosening scale. 



c. Normal Buteo bill. 



did not seem serious, after a minute she 

 often made an investigation and 'even 

 changed the hiding place. When hungry 

 again she remembered her hidden store 

 and, if it had been removed unbeknown 

 to her, siiowed disappointment and per 

 plexity most plainly. 



Perhaps from a strictl.y scientific stand 

 point tlie most interesting discovery made 

 from this little bird was the method ol 

 growth of her bill. The Sparrow Hawk, 

 though small, is a true Falcon, a "Noble 

 Falcon" in the old vocabulaiy of venery 

 The bill of this group of raptores is dis 

 tinguished from the less esteemed hawkf 

 by having a distinct notch and tooth on 

 the cutting edge of the upper mandible 

 just back of the hook. This tooth there 

 fore is an important point in the classi 

 fication of the order. Falco lived largely 

 on soft meat, and her bill Avithout the 

 natural friction and wear and tear againsi 

 the hard bony parts of normal prey over 

 grew. When this occured the notch form 

 ing the tooth became almost obliterated, 

 and the bill tended to resemble the form 

 and character of the non-falconine hawks 

 with a smoothl}'^ outlined lobe on the cut 

 ting edge. When this abnormal condi 

 tion became well developed, and it seem 

 ed as if a falcon Avas about to assume a 

 Buteo or Accipiter character, a crach 



