Pedernales Falls State Park Prothonotary Warbler Nest Box Study: Wilson's Warbler & Nest Occurrences

Prothonotary Warbler Occurrence In Texas

Central Texas draws the western line for the Prothonotary Warbler range. This species occupies much of eastern North America up to the southern boarder of Ontario Canada.
Prothonotarys' nest in natural cavities but also readily use nest boxes located on or near water. Flooded swamps represent ideal habitat but they will also nest along rivers or small bodies of water.
In May 2007 I saw a brightly colored male Prothonotary Warbler at Pedernales Falls State Park bird blind. After some research I learned male birds have been seen building nests in neighboring counties to Blanco County. Further research revealed a pair of Prothonotary Warblers successfully nested at Heard Wildlife Sanctuary in McKinney, Texas.
In December 2007 I decided to undertake a nest box study at the park. January through February 2008 I hiked the entire Pedernales River and tributaries within park boundaries, in an effort to choose the best sites. Habitat selection proved a challenge do to high flood levels along the river.
Five sights were eventually selected where two nest boxes each were placed. Most boxes were attached to trees however two were attached to metal poles. These boxes were monitored from March through June 2008 on a weekly basis. A Breeding Bird Study was conducted at each nestbox location in 2008 and will be continued in 2009.

Sunday, April 6, 2008

Wilson's Warbler & Nest Occurrences

Northern Parula's were singing everywhere today as were a number of Summer Tanagers. I had six species of warblers including a female Wilson's Warbler and the Louisiana Waterthrush, for the second week in a row, at Tobacco Creek. Both the Yellow-throated and Blue-headed Vireos made appearances today. The Blue-headed Vireo is migrating north to Canada, but the Yellow-throated Vireo will stay to nest here where it's habitat is restricted to riparian corridors.

I found two active nests today but not in my nest boxes.

Both were found at the Tobacco Creek site, which may be the most diverse site of the five. A Carolina Chickadee is nesting in a cavity in a pecan tree right above nest box 5. This cavity is 20 feet up. The second nest was under construction by a female White-eyed Vireo. This hanging nest is 9 feet high in a Buckeye tree also located near nest box 5 at Tobacco Creek.

Some Buckeye were still in bloom, however its peak flowering is over. I only saw half as many hummingbirds around these flowers and all were Black-chinned Hummingbirds, the majority of which were females.

A pair of Green Kingfishers have been sited again at East Park Boundary and I got my first Broad-winged Hawk of the year at Twin Falls.