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.

Sunday, January 25, 2009

January Nest Box Repairs & Bird Blind Visit

Today I waited until temperatures warmed to the high 40's before venturing out to the park as my plan was to mountain bike to East Park Boundary 3-1/2 miles distant from the Primitive Campground parking lot. Lucky for me I did not have to do that.
I was very fortunate to connect up with Bill McDaniel, park manager, who put me in touch with Lynn Kuenstler, a State Park Peace Officer. Lynn drove me out to Tobacco Creek and East Park Boundary nest box sites. My aim today was to remove the fronts of the boxes so I can open the entrance holes to 1-1/2" wide by 2+" in height. We also visited Twin Falls nest boxes #1 & 2. At Twin Falls a trespasser gained access to the pool area, pulled one nest box with pole out of the ground and threw it into the deep pool. Lucky the weight of the pole and box did not allow for a far throw, whereby Lynn was able to pull the box out of the pool. I also learned today the location of a Mountain Lion sighting made last Fall at Jones Springs, relatively close to one of my nest box sites.

At the bird blind there were still a couple of Pine Siskins, one Dark-eyed Junco, a White-throated Sparrow and a Fox Sparrow, along with an Orange-crowned Warbler and a Ruby-crowned Kinglet. On the drive out of the park I spotted two Common Ravens soaring high in the sky. I believe this to be a mated pair who will be nesting soon either in a stick nest built in a tree or on a rock outcrop. Ravens mate for life and have a territory approximately 10 square miles or larger. This all depends on food availability.

Saturday, January 3, 2009

Pedernales Falls State Park 2009

Warm temperatures and fair skies brought me out to the park today as I envision a second year of breeding bird surveys along the river at Pedernales Falls State Park in Blanco County. I will be surveying all ten nestboxes, and recording all birds seen and heard at each location. Nestbox openings will be enlarged to an oval shape to accommodate more species, and to make it more inviting for Prothonotary Warblers.
Last year's bird research was setup to attract the Prothonotary Warbler to manmade nestboxes along the river. It is important to point out here that this part of Texas represents the western most range of this species and nesting attempts have been recorded in neighboring counties. However, because I did not see any Prothonotary Warblers during the 2008 bird surveys, the new 2009 study will be renamed to: Pedernales Falls State Park Breeding Bird Survey.
All birds observed and heard for a ten minute period, will be recorded at each nestbox during the breeding season, including nesting activity and fledglings. I expect the surveys will begin mid-March, as this is the time male Golden-cheeked Warblers begin setting up territory, and surveys will end sometime mid-July.
Today at the bird blind a single Fox Sparrow gave an occasional appearance along with a Dark-eyed Junco, two White-throated, several Lincoln's, and one Rufous-crowned sparrow. There were many Pine Siskins and American Goldfinches, plus two Orange-crowned Warblers and the usual year-round residents.
After visiting the bird blind I proceeded to mountain bike the Wolf Mountain Trail for a gorgeous day in the park. Temperatures reached the low 80's. Perfect weather to be biking in this beautiful hill country.