THE tree swallow is one of the many birds that nest at high altitude in the Wasatch Mountains. The favorite nesting places of these square-tailed gleaners of the air are old sapsuckers' holes, and in suitable clusters of mountain ash trees, they often nest in colonies of several dozen pairs.

The situation of their nests puts a difficulty in the way of photographing them. I found, however, a nest in an ash that was close to another ash; the accompanying picture explains the method by which photographs were secured. Cross pieces nailed one above the other furnished a ladder up the unoccupied tree, and a slab nailed at the proper height pointing directly at the nest hole served as a support for the camera, which was clamped on with a universal clamp. Although this did not bring the lens so close to its object as could have been desired, the arrangement was otherwise very convenient.

This pair of swallows showed practically no fear of the camera, and while I snapped most of the pictures from below (using a thread), they would come and go when I was up changing films. The old birds were carrying in food when this nest was discovered about June 24th. After it had fed the young, each bird remained impatiently waiting in the entrance during the three or four minutes that usually elapsed before the arrival of its mate. The bird waiting always greeted its returning mate with a twittering welcome, and then soared forth immediately into the sky. The above precaution may have been for the purpose of guarding the newly-hatched young against the inroads of thieving sapsuckers.

About ten days after the discovery of the nest the first signs of life were heard from within the hole, and a few days later the young swallows appeared at the entrance looking interestedly out at the world. As their doorway was only large enough to hold one at a time, there was a continual struggle for this point of vantage. The young must now have been between two and three weeks old, judging from the time the nest was found, and the old birds no longer guarded the entrance. They usually pushed the eager young back before feeding them. They had grown very irritable for some reason, perhaps from having to hurry so strenuously for a livelihood, for they fought each other off when meeting at the nest, and once inside one frequently sat there malignantly preventing its mate from entering.

Three weeks after discovering the nest, I enlarged the entrance in order to remove and photograph the young swallows. I was not surprised when the first of the three young in this brood, slipping through my fingers, soared away as if it had flown for many a month. But my patience was severely tried before I succeeded in inducing the remaining two to sit still long enough to be photographed. Just as they were well placed the irate parents, darting down with sonorous whirring of wings, would set them off into another paroxysm of activity. Once having seen the outside world, they refused thereafter to remain in their former home; but their chirps in the tree-tops during following days were evidence that they did not immediately leave the vicinity.

IN THE FOREGROUND THE BUSH WILLOWS ARE SEEN FOLLOWING A WINDING CREEK. BEYOND ARE THE ASPEN TREES IN WHICH THE TREE SWALLOWS, PARKMAN'S WRENS, AND MANY OTHER BIRDS NEST. WITHIN A HUNDRED YARDS OR SO INCLUDED IN THIS PICTURE WERE THE NESTS OF A YELLOW WARBLER, A HUMMING-BIRD, AND NUMEROUS SAP-SUCKERS AND TREE SWALLOWS


A SERIES OF CROSS PIECES FORMED A LADDER UP TO THE SLAB ON WHICH THE CAMERA WAS CLAM PEI). THIS BROUGHT THE INSTRUMENT WITHIN ABOUT SIX FEET OF THE HOLE IN THE OPPOSITE TREE


THE SWALLOWS RETURNED AT INTERVALS OF FIVE OR TEN MINUTES. FROM THE BILL FULL OF INSECTS SHOWN HERE ONE MAY JUDGE WHAT A QUANTITY OF INSECTS THE YOUNG CONSUME

THE OPEN BEAK OF A YOUNG SWALLOW BEGGING FOR FOOD MAY BE SEEN WITHIN THE HOLE

THE NEST HOLE WAS ENLARGED AND THE YOUNG REMOVED IN ORDER TO PHOTOGRAPH THEM, A DAY OR TWO BEFORE THEY WOULD OTHERWISE HAVE LEFT. ONE OF THE YOUNG ESCAPED AND THE REMAINING TWO CAUSED THE PHOTOGRAPHER CONSIDERABLE DIFFICULTY BY REFUSING TO REMAIN ON THE PERCH


A BACK VIEW


SWALLOW CLEANING THE NEST

THREE YOUNG TREE SWALLOWS, AND AN ADULT FLYING. AFTER LEAVING THE NEST THEY ARE FED FOR SEVERAL WEEKS. THE PARENTS DO NOT ALIGHT, BARELY PAUSING IN THEIR FLIGHT AS THEY DELIVER THE FOOD