Pedernales Falls State Park Prothonotary Warbler Nest Box Study: Sunny Day Nest Box Repairs & Site Visits

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.

Saturday, January 31, 2009

Sunny Day Nest Box Repairs & Site Visits

A gorgeous day in Texas Hill Country to enjoy a bit of nature at Pedernales Falls State Park. Today Bill McDaniel, park manager, helped me install all ten nest box fronts back to their original sites along the Pedernales River and Twin Falls.

At Hackenberg Creek nest boxes 7 & 8 were moved down from the grassy plateau to the edge of the Pedernales River and placed on Bald Cypress trees. Nest box 4, at Trammel Crossing, was relocated onto a Hackberry tree slightly closer to the river, and at Tobacco Creek nest box 6 was moved from a grassy plateau down to an island mounted on a

Bald Cypress. It was here where we walked upon a mature Bald Eagle perched along the river at the top of a cypress tree. This bird was very tolerant of our presence and remained perched for a good ten minutes before our close approach caused it to fly upstream. We wondered if this was a nesting adult and where its nest might be or whether it was a winter vagrant.

All the nest boxes are in place now with new, larger openings routed out by one of the park staff - Blake Gayler. I believe these boxes are in place in time for even the year-round resident birds to make use of as they can begin nesting earlier than those that migrate. With the new size openings at 1-1/2" wide by 2" tall we could see activity by the Carolina Chickadee, wren species, the Black-crested Titmouse, and perhaps a woodpecker. Of course I am still hopeful to attract a Prothonotary Warbler come April or May.

Many thanks go to Bill McDaniel for helping me resize the nest box openings and gaining vehicular access to my more remote study sites.