NEW HOME CONSTRUCTION BENEFITS BIRDS OF UNION COUNTY
By Dick Mason
Observer Staff Writer
When tree swallows are upset they express their feelings one twig at a time.
Dave Larson, manager of the Ladd Marsh Wildlife Area, has seen this first hand.
Larson has found that many birds, particularly tree swallows, are remarkably territorial when nesting. This becomes strikingly apparent when hes installing bird boxes for tree swallows at the wildlife area.
When the bird boxes are placed less than 75 feet from one another the swallows become disturbed.
If the bird boxes are too close the swallows will fill the surrounding boxes with twigs, Larson said.
This keeps other birds from using them as nesting structures, protecting the swallows nesting territory.
Proper spacing is one of many things people need to be aware of when installing nesting structures, volunteers at Saturdays birdhouse building day learned.
Volunteers learned about the basics of building and installing bird structures. They built more than 130 structures, including 80 bluebird houses, 12 great gray owl platforms, five Canada goose platforms and 30 wood duck boxes. The structures are being distributed to sites throughout Union County, including the Ladd Marsh Wildlife Area.
Ladd Marsh boasts at least 50 Canada goose nesting boxes, most of which were made during the annual bird box building days conducted by the Grande Ronde Bird Club and Friends of Ladd Marsh.
The Canada goose nesting boxes are attached to railroad ties that are several feet high.
The platforms are having a noteworthy impact on nesting success, Larson said. He noted that studies conducted throughout the United States indicate that when geese nest at ground level they have a 60 percent chance of successfully raising a brood. The chances of nesting success jump to 90 percent when geese use elevated nesting platforms because elevated nesting platforms protect geese from predators such as weasels and raccoons.
The platforms at Ladd Marsh provide added protection because sheets of metal are nailed to the railroad ties. This prevents predators from climbing up the poles to reach goose nests, said Jim Ward of the Grande Ronde Bird Club.
Helping birds with structures involves more than constructing them correctly. Placement is also critical, volunteers were told Saturday.
Ward noted that people who put up a goose nest box on a small pond should not assume that the nesting structure will attract geese. Geese prefer to nest in larger expanses of water, which gives them more opportunities to escape predators.
People putting up bluebird boxes also need to be aware of placement. Ward said that people should not expect to attract bluebirds by placing structures on the floor of the Grande Ronde Valley. Bluebirds prefer hilly areas.
The eggs and young in nests have a better chance of survival in structures that are not shallow. Deeper structures make it harder for predators such as raccoons and starlings to reach into a bird box and get young and eggs.
Although it is important to keep predators out of bird boxes, it also is important that the young are able to escape. Bird boxes should be slightly tilted forward, Ward said.
Bird box building days have been conducted at the Ladd Marsh Wildlife Area for about seven years. The structures are compensating cavity nesting species for the loss of nesting habitat.
Ward said it is quite evident that cavity nesters are in need of structures. Sometimes bluebirds will claim structures he puts up within an hour.
Ward recalled that once he had a bluebird excitedly begin inspecting bird boxes while they were still in the back of his pickup.
People interested in obtaining birdhouses should call the Oregon Department of Fish and Wildlife at 963-2138.