22 PACIFIC COAST AVIFAUNA No. 14 



the breeding season are found nowhei-e else. Tliesc birds arc the ^VKrl)linj>; Vireo 

 and Orange-crowned WarbU^r. Otlier species found in lliis association occasion- 

 ally are the Red-naped Sai)sueker, Hammond Flycatclier, ^lacGillivray Warbhu" 

 and Rol)in. 



The one association of mixed bi^oad-lcal' -.mhI conifcious trees is found in the 

 norlliwcstern mountain region, as fd)()ut the shores ol" l-Mathcad l.akc. In this 

 association the main trees are conifers, most of the broad-leaf trees being small 

 ones which form an undergrowth beneatli the conifers. The conifers ai-e mainly 

 yellow pine, Douglas fir and tamarack, and the ])road-leafs are cotton wood, birch 

 \Iiviula papyrifcra and B. fo)}titialis) , alder (Ahnis tciniifolin) . and a few 

 smaller species that are hardly more than shrub si/e. The l)irds of this associa- 

 tion are the Cedar Waxwing, Red-eyed and Warbling vii-eos, AuduI)on Warbler, 

 Redstart, Eastern Chickadee, Olive-backed Tlu-ush, and Robin. 



The coniferous ti'ee associations occur entirely in the mountains, except the 

 yellow ])ine, which occurs on the slopes of the pine hills and })rairie buttes in the 

 l)r'airie region, as well as in the mountains. The chief associations ai-e yellow 

 pine, lodgepole pine, limber pine, white-bark pine, Douglas fir, fir and tanuiracK. 

 p]ngelmann spruce, and arbor-vitae. Western white pine also forms an associa- 

 tion locally, we.st of the continental divide, but it is an association T have not 

 seen and, except for the report that the Chestnut-backed Chickadee is found in 

 it, 1 know nothing about it. 



Yellow pine is entirely a Transition association, occurring in tlie i)inc hills 

 of the prairie region and on the lower mountain slopes. Across the continental 

 divide it is found mainly through the center of the state. East of the divide it is 

 not found up to the upper limits of the Transition zone, but is (^itirely belov*- 

 4,500 feet' elevation. In southwestern JMontana it is not found at all, the eleva- 

 tions in the lower mountains being too high. The southern limits of its range 

 southward are on Sixteen Mile Creek in extreme northern Gallatin County, on 

 the Boulder River south to Basin in Jefferson County, and on Pike's Peak Creek 

 near Pioneer in Powell County. The northern limits of this association east of 

 the divide are on the Dearborn River, in Lewis and Clark County, but west of 

 1lie divide the association extends iioiHi into Glaciei' Park and ])r(»bably to tlie 

 northern boundary of the state. The distribution of this association accounts 

 for the breeding ranges of its most chai-acteristic species in the state, and they 

 will be sought in the breeding season in vain in |)laces whei'e yellow |)ine is nor 

 found. These species are the Crossl)ill and Red-breasted Nuthatch, and west of 

 the divide the Pileated Woodpecker. The Evening (Ji-osbeak and Pygmy Nut- 

 hatch arc probably also cliar'acteristic. Othei- s])ecies bi'ccdiug in this associa- 

 tion are the Spai-row Hawk, Haii-y Woodjiecker, Flicker, Westc;-n Wood Pewee, 

 Cassin l*ur])le Finch, Pine Siskin. Kobiu and Mountain Bluebird. 



The lodgepole pine association is characteristic of the ('ar.adian zone, being 

 found entirely within that zone. (See fig. 7.) It consists of a rather dense for- 

 est of lodgepole pine, with pi'actically no other trees. The forest floor is some- 

 times open and carpeted with pine needles and a few small plants such as a 

 small red-bei'ried V(ii< in'ni iii : soiiiet iiiies, esi)eeiall\' wliei'e there have been forest 

 fires, it is covered with down timber, and sometimes, in moist situations, with a 



