BIRDS. 



181 



tree swallows with their snowy uiiderparts and burnished steel-blue 

 upperparts. The parents were still going to the nest holes, which 

 Avere respectively about 8, 15, and 20 feet from the ground, but part 

 of each faniih' seemed to have floAAii and the air was alive with birds 

 weaving about among the trees. Toward sunset we found a number 

 of them on the telephone line that marks the boundary of the park. 

 They and some mountain bluebirds had possession of the wires, but 

 though there seemed to be abundant space, the swallows apparently 

 wanted it all. Several times there was 

 a heated chase, and once when a gentle 

 bluebird was driven low it actually sat 

 down on the ground and let the domi- 

 neering swallow go by. 



At Mirror Pond near the Gunsight 

 Trail tree swallows and probably cliff 

 swalloAvs were flj'ing about over the 

 quiet water with its yellowish green 

 marshjT^ border, disappearing up the 

 river vista with its beautiful view of 

 Gunsight Pass and its guarding peaks. 



NORTHEEX ViOLET-GREEX SwALLOW : 



Tachycineta thaJassina lepida. — The 

 swallows of the park need to be very 

 carefully discriminated. The two with the brown breast are the barn 

 swallow with the long forked tail, and the cliff swallow with the light 

 forehead and pale rufous rump, while the two that are snow white 

 underneath are the tice swallow, with the steel-blue upperparts, and 

 the violet-green swallow, Avhose green crown and back contrast 

 sharply with the violet of the rump patch. The cliff' swallow makes 

 a retort-shaped mud nest, often hung from a cliff or roofing slab of 

 rock, while the barn swallow makes a cup-shaped 

 nnid nest often attached as a v»'all pocket to a rafter 

 in a barn. The tree and violet-green swallows nest 

 in holes in trees, and the violet also in cliffs. As it 

 will nest in knot holes and bird houses, it is one of 

 the birds that may be attracted by offers of hospi- 

 tality. It would be worth while trying to attract 

 it by bird houses at Lake McDonald, as it has recently been found on 

 McDonald Creek. 



Bakk Swallow^: Riparia riparia riparia {?) — Like the tree and 

 violet-green, the bank swallow is white underneath, but it has a dark 

 band across the chest that distinguishes it, and it nests in colonies in 

 banks such as railroad cuts or creek eml)ankments. A nesting colony 

 has been reported by Mr. Gibb from the Swiftcurrent, probably of 



I B^ologxal Survey. 



Fig. 81. — Baiu 



-wallow. 



From Handbook of Birds. 



Fig. 82. — Tree swal 

 low. 



