BIRDS. 



181 



tree swallows with their snowy underparts and burnished steel-blue 

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

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

 of each family seemed to have flown and the air was alive with birds 

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

 of them on the telephone line that marks the 1;oundary of the park. 

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

 (hough 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 actuallj' 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 



swallows were flying about over the 



quiet water with its yellowish green 



marshy border, disappearing up the 



river vista with its beautiful view of 



Gunsight Pass and its guarding peaks. 



NOETHEEN ViOLET-GEEEN SaV ALLOW : 



TacJii/cineta thalassina lepicla. — 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 tree swallow, with the steel-blue upperparts, and 

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

 sharply Avith 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 

 nmd nest often attached as a wall 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. 



Bank 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 embankments. A nesting colony 

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



I Biological Survey. 



Fig. 81. — Barn 



From Handbook o£ Birds. 



Fig. 82. — Tree swal- 

 low. 



