Iij. Drew oh the Vertical Range of Bird-, in Colorado. [January 



with further notes on temperature and the flora, may eventually 

 serve to show to what extent there is a correspondence between 

 vertical and latitudinal distribution. As most of the birds noted 

 are summer visitants, the column showing winter range is 

 mostly blank. The upper nesting limit is- usually easily deter- 

 minedj the lower not so readily, as many species, in suitable 

 localities, nest down to sea-level. But in some cases, as in 

 Lagopiis latcurits, Regulus calendula, and some others, quite 

 well-defined limits exist, above or below which few. if any, 

 of these birds are found during the nesting season. 



Loph ortyx califor/eiau/is, Ortyx virgiuiaii/is. and perhaps 

 some others, have been introduced in the vicinity of Denver, but 

 probably as yet their range does not extend above =;ooo feet. 



The figures in the columns under the headings, 'Spring,' 

 'Summer,' etc., refer to elevations in feet above sea-level. The 

 'Breeding Range' will give the full summer distribution of those 

 remaining through that season. In the records of spring and fall 

 migrants I have aimed to show how high the birds wander, and so 

 have merely noted the upper limit of the range of birds which are 

 generally distributed below the altitude given. But in the case 

 of birds of erratic or little-known distribution, both the upper 

 and lower levels inclosing their range are given. A ? follow- 

 ing the figures in a few cases means probability amounting 

 almost to certainty. The 'Plains' include a large part of adjoin- 

 ing Kansas. 



The nomenclature is that of Ridgwav's ' Catalogue of the 

 Birds of North America.' But if sub-species ' montana ' is 

 merelv a modified form of Certhia familiar is rufa, why not put 

 it so, and let it be understood that the last-named form is merelv a 

 modification of the preceding, as is now so well accepted in the 

 case of varieties of the first remove? The same applies to 

 Pipilo maculatus arcticus megalonyx. 



