Pedernales Falls State Park Prothonotary Warbler Nest Box Study: Breeding Bird Season At Pedernales

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, May 3, 2008

Breeding Bird Season At Pedernales

It was a gorgeous day at the park as evidenced by the many visitors to the Falls and the hiking trails. All the deciduous trees appear to be fully leafed out now so there are plenty of caterpillars to go around. Just about every bird I could get my binoculars on was dining on a caterpillar.

Highlights of the day were an Acadian Flycatcher at Tobacco Creek, an Ovenbird and Common Yellowthroat at East Park Boundary, and a Great-crested Flycatcher at Hackenburg Creek.

Northern Waterthrushes appear to be paired and breeding at three locations on my study route. Carolina Chickadees already have fledged young. The female White-eyed Vireo was sitting tight on her nest, and there was no activity at the Black-chinned Hummingbird nest.

I don't hear the song of Summer Tanagers anymore, however, they are present in pairs at all my study sites. Now that they are paired they are using a contact call.

Ovenbirds are a unique warbler that nest on the ground. They have a very distinctive song. They repeat "teacher, teacher, teacher" very loadly. I have found Ovenbird nests in Northern Michigan. They are domed, made of grass, and have a side entrance.

I finally discovered the Rock Squirrels which hang out around the steep rocky slopes along the Pedernales River. They are mostly black with lighter spots on the rump. This is a cool looking ground squirrel as compared to the arboreal Fox Squirrel, the more common squirrel of this area.

The butterfly photo above I believe to be a Little Wood Satyr butterfly.

2 comments:

Mikael Behrens said...: Neat, you seem to have a real knack for finding nests! Love the butterfly picture.; May 3, 2008 at 10:05 PM
Anonymous said...: I used to think finding a Hummingbird nest was impossible until last spring when Trey Kelley and I were out surveying the Barton Creek Greenbelt. 30' up a tree along a ravine Trey found one. When a bird builds a nest they draw much more attention to it. I bet the Brown-headed Cowbird is a master at watching for nest building activity?; May 4, 2008 at 2:43 PM