362 THEOUGH THE MACKEN"ZIE BASIl^ 



partially-formed embryos. In a few cases also, young birds 

 were found in the same nest with eggs the contents of which 

 were but little changed, and in another nest a perfectly fresh 

 egg was found with several ready to hatch. In nearly every 

 case the eggs seemed to be in different stages of development, 

 and incubation seems to begin as soon as the first egg is laid. 

 The latest date on which eggs were found by Mr. MacFarlane, 

 according to the records in the United States iN'ational 

 Museum, is 12th June, 1864, when two sets of four eggs 

 each were taken." 



The Major farther on writes: "Mr. James Lockhart 

 found the gyrf alcon breeding on the Yukon River one hun- 

 dred miles above the mouth of the Porcupine River, and 

 took a nest and three eggs there in June, 1862. Messrs. 

 McDougall and Jones also took their eggs near Fort Yukon, 

 Alaska, in 1865, and all of these specimens are now in the 

 TJ. S. National Museum collection. From our present 

 knowledge it appears that the gyrf alcon breeds north of. 

 latitude 65°. It has not been found nesting farther south 

 than this. In the general pattern of markings the eggs of 

 the gyrf alcon approach those of the prairie falcon (Falco 

 mezicanus) much closer than those of the duck hawk {Falco 

 peregrinus anatum), which as a rule are much darker. In 

 shape they vary from ovate to rounded ovate. The shells 

 of these eggs feel rough to the touch, are irregularly granu- 

 lated, and without lustre." It is my belief that this falcon 

 is a " winterer " in the northern territories of Canada, where 

 its prey would chiefly consist of partridges, rabbits, and ptar- 

 migan. The allied F. rusticolUs (Linn.), or more probably 

 F. islandus (Brunn.), breed in small numbers in the Ander- 

 son region, as the Indians often spoke of a large whitish 

 hawk, since observed by myself, which had successfully 

 eluded all attempts to capture itself or its eggs. On the 

 other hand, Professor John Macoun states that " there is no 

 doubt but that this form was included in F. islandus by Sir 

 John Richardson, as he found the birds nesting where Mac- 



