March, 1921. 



The Canadian Field-Nat[;kalist. 



43 



iiig tliem at this time without a special 

 'search. 



In regard to the winter range of the 

 species, as contrasted witli its summer 

 range, there lias been a decided cliange of 

 late years, a change that is very apparent 

 at Ottawa, but observable probably else- 

 where as well. The old reports of the 

 species would indicate that originally it 

 was a very rare as well as a very erratic 

 visitor, although numerous enough when- 

 ever it did come. Latterly, however, it has 

 appeared so much more often that it can 

 be regarded as almost regular. It is true 

 that none have been seen this winter, but 

 then this has been an unusual winter in 

 every way, and if Evening Grosbeaks have 

 not appeared, neither have other species 

 upon whose presence we can more usually 

 count. According to the record, while the 

 Evening Grosbeak has gradually become 

 more regular in the locality of Ottawa, 

 other winter species such as the Pine Gros- 

 beaks, the Crossbills, the Bohemian Wax- 

 wings, the Eastern Horned Larks, the Red- 

 Polls and the Snow-Buntings have become 

 much less so. A possible, even a probable 

 explanation of this newly-acquired reg- 

 ularity of the Evening Grosbeaks may be 

 found in the recent spread of the Mani- 

 toba maple, Acer negundo. John Ma- 

 coun has recorded what was probably 

 nearly the original distribution of this tree 

 in Canada. '^ Outside of a few trees grow- 

 ing in Toronto he did not meet with it 

 again to the west until beyond Lake Supe- 

 rior in the northern parts of the prairie 

 provinces. Now the samaras or winged 

 seeds of this maple hang to the tree all 

 winter, and whenever obtainable constitute 

 the principal food of the Evening Gros- 

 beak. Indeed, when the seeds finally drop 

 off, the birds descend to the ground and 

 rarely leave the locality until the supply 

 is exhausted. In the early days, with so 

 large an area of country barren of their 

 favorite food, it is not surprising that the 

 birds onlj' strayed over it in exceptional 

 winters under pressure of food failure else- 

 M'here. Today, however, the distribution 

 of tliis maple is radically different. It is 

 a hardy, quick-growing shade tree, and in 

 consequence has been planted extensively. 



not only about many farm hou.ses, but in 

 all the villages, towns and cities that have 

 sprung up to the east and north of the 

 Great Lakes. Thus a baited ])athway has 

 been laid fi-om the usual summer home of 

 the Evening Grosbeak right to our doors, 

 and undoubtedly the bird has taken ad- 

 vantage of this fact to travel our way 

 more often than it did before. It may even 

 be prophesied that with the further in- 

 crease of the Manitoba maple northward, 

 the Evening Grosbeak will find suffi- 

 cient food nearer its summer home and 

 again become scarcer in our neiglibour- 

 hood; for it was the extension of cultiva- 

 tion in similar localities that seems to have 

 brought about a like change in the move- 

 ments of the other birds that I have men- 

 tioned. 



The Western Evening Grosbeak, Hespe- 

 riphona vespcrtina montana, was separated 

 from the eastern bird on account of some 

 slight colour differences and £l relatively 

 greater length of bill. For a long time our 

 British Columbian Grosbeaks were, as a 

 matter of course, referred to the western 

 race. It has been evident for some time, 

 however, that while they may be different 

 from the eastern birds, they are certainly 

 not the montana as originally disposed, 

 with which they agree neither in colour 

 details nor in the shape of the bill. Jos. 

 Grinnell, the first to try to unravel the 

 subject, '- subdivided the birds previously 

 grouped under the head of montana into 

 three races, montana, californica and 

 hrooksi, and referred the British Colum- 

 bian and the AVashington birds to the last 

 named subspecies. He based his distinctions 

 on variations in colour and bill form. Now 

 one trouble in estimating the values of 

 these different characters is the difficulty 

 of obtaining comparable material. All our 

 specimens of true eastern vcsprrtina are in 

 winter plr.mage, while the majority of 

 British Columbian specimens are in sum- 

 mer condition. Allowing for this, how- 

 ever, an examination of the few winter 

 western birds available seems to indicate 

 tliat while the width of yellow on the 

 forehead and the back coloratinii of the 

 male in the hrooJcsi can be readily matched 

 in specimens of the eastern bird, the dark- 



11 Macoi'n. Cat. Canadian Plants, Pt. T. Poly- 

 petalae. 1883. 



icOrinnell. Condor, xix. liMT. pp. 17-22. 



