Oet.-Dec. 1921. 



Thk Caxadiax Field-Xatiralist 



139 



out the ration. Tlii.s trait undoubtedly 

 extends the 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 al)undant 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 

 lier liead under her wing as it is generally 

 desci'ibed, although really the head is 

 liidden under the interscapular feathers 

 between the shoulders. 



Wishing to obtain a photograph of her 

 in this attitude a camera was set con- 

 venientl}^ and late at night, when she 

 was sound asleep, an explosive magnesium 

 flash Avas fired. Of course she awoke im- 

 mediately, but the speed of her movement 

 was only appreciated Avhen the resultant 

 negative was developed. It presented two 

 clear superimposed images without blur 

 between. One showed her 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 surely 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 

 numner that 1 am convinced that it Avas 

 instinctive and is a regular specific habit. 

 1 haA'e seen no suggestion to this in the 

 literature relating to the Avild bird. This 

 case may not prove beyond question that 

 Avild S})arroAV IlaAvks do hide stores, but it 

 is strongly suggestive of its probability 

 When hunger Avas temporarily satisfied, 

 the unconsumed remaiiuler of the supplies 

 was invarialjly carried in the bill to one 

 of several usual hiding places. The most 

 favored one Avas on top of the electric 

 meter on the Avail nearby. She aa'ouUI 

 place the valued bit in the depression be- 



tAveen the top of the meter and the Avail, 

 and stamp it doAvn Avith liei" feet in a 

 business-like manner, churring Avith a note 

 of exultation and then AvithdraAving tc 

 vicAv results. If not satisfied she Avould 

 return and rearrange and hammer il 

 again and Avhen satisfied seek her perch 

 Any time thereafter a motion on our pari 

 toAvards lier store Avould arouse anxious 

 interest, and if the threatened theft Avere 

 pressed she was immediately on hand to 

 protect her property. Even if the attempt 



a. — Normal falcon bill. 



b. — Overgrown falcon bill, showing tendency of 

 growth and loosening' scale. 



c. — Normal Buteo bill. 



did not seem serious, after a minute she 

 often made an iuA'estigation and eA'en 

 changed the hiding place. When hungry 

 again she remembered her hidden store 

 and, if it had been removed unbeknoAAi! 

 to her, shoAved disa])pointnicnt and per 

 plexity most plainly. 



Perhaps from a strictly scientific stand 

 point the most interesting discoA'ery made 

 from this little bird Avas the method oi 

 groAvth of her bill. The SparroAv IlaAvk, 

 tliough small, is a true Falcon, a "Noble 

 Falcon" in the old vocabulary of venery 

 The bill of this group of raptores is dis 

 tinguished from the less esteemed haAvkj? 

 by having a distinct notch and tooth ois 

 the cutting edge of the upper mandible 

 just back of the hook. This tooth there 

 fore is an important jioint in the elassi 

 fication of the order. Falco lived largeh 

 on soft meat, and her bill Avithout the 

 natural friction and Avear and tear against 

 the hard bony i)arts 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 

 anil character of the non-falconine haAvk^ 

 Avitli a smoothly outlined lobe on the cut- 

 ting edge. When tiiis abnormal eondi 

 tion became Avell developed, and it seem 

 ed as if a falcon Avas aooirt. to assume a 

 Hi teo or Accipiter character, a craefe 



