Texas Ornithological Society Abstracts

Pasted below are a number of abstracts presented at Texas Ornithological Society Science Sessions.

BIRD USAGE OF RUNNING LIVEOAK WOODLANDS NEAR THE COAST IN CALHOUN COUNTY, TX

BRENT ORTEGO, Texas Parks and Wildlife Department, Victoria, TX

Abstract: Birds were mist-netted during the spring and fall of 2001 and 2002 in expansive running liveoak (Quercus virginiana) woodlands that were 4 and 10 miles inland from Matagorda Bay and Gulf of Mexico, respectively, in Calhoun County Texas. The woodlands were a mosaic of running liveoak less than 10 feet tall and coastal prairie in a 35,000-acre area that was comprised roughly of 50% of each between Powderhorn Lake and Matagorda Bay.

1200 (12-meter long with 30-mm mesh) mist-net hours were used during the spring and 2500 during the fall of two years to sample resident and migrant birds during March and April, and August through October. Although, roughly the same number of species were captured each season (55 in spring and 58 in fall), the frequency of captures were twice as high in the fall (50 per 100 net-hours vs. 24). Fall neotropical migrants and flycatchers were netted 6 times and warblers 4 times more frequent than spring. The only species group more abundant in spring were neotropical thrushes which were caught at .6 birds per 100 net-hours and non were captured in fall. At the distance of the study area from the Gulf, most spring inland bound migrants needing to make emergency landings probably did so prior to reaching the study area and those more fit migrants flew over the study area before making first land fall. In contrast, fall migrants made frequent use of the woodlands for foraging prior to migrating over or around the Gulf.

Impact of a Level 1 Hurricane on nesting Bald Eagles in Texas.

Brent Ortego Texas Parks and Wildlife Department, 2805 N. Navarro, S600B, Victoria, TX 77901; brent.Ortego@tpwd.state.tx.us

Hurricane Claudette passed through Texas coastal counties during July 2003 as a level 1 hurricane. Bald Eagle nesting data from 8 counties that were not impacted by the hurricane were compared to 7 counties that were. Noticeable hurricane impacts were mostly knocking down nests and tall trees that potentially would serve as nests in the future. Eagles in this part of Texas typically replace nests at 4 year intervals. Thus, about 25% of the nests are normally replaced each year. Seven nests in the 7 counties within the path of the hurricane were known to have been destroyed by the storm and all were rebuilt during the following fall when nesting commenced. The 8 adjoining non-impacted counties had 14 nesting attempts fledge 22 eagles before the hurricane in 2003 and 16 nesting attempts and fledge 32 eagles after the hurricane in 2004. The 7 impacted counties had 19 nesting attempts before the hurricane fledge 31 eagles in 2003, and 20 nesting attempts fledge 33 eagles after the hurricane in 2004. Short term lost of nests was the only noted impact.

Texas Breeding Bird Survey

BRENT ORTEGO, Texas Parks and Wildlife Department, Victoria, TX; brent.Ortego@tpwd.state.tx.us

The U. S. Breeding Bird Survey (BBS) is a highly standardized 24.5 mile survey randomly located along public roads throughout Texas, and is used to monitor population trends and estimate densities of breeding birds in Texas by ecoregion. The survey started in Texas in 1967. It was coordinated by Warren Pulich until 1993 and was taken over by me with periodic assistance from co-coordinators.

BBS volunteers work primarily anonymously. They get very little recognition, but produce the data on which many conservation organizations depend. Their common theme is that they love counting birds and are concerned about their status. 417 birders have conducted the 195 BBS routes in Texas since its beginning. Kenneth Seyffert has conducted the most surveys in TX by running BBS routes 149 times. Other noteworthy surveyors are Francis Williams conducting 74, James Middleton 65, Richard Albert 63, Brent Ortego 61, Charles Crabtree, Jr., 59, Peggy Accord & Kenneth Nanney 58, and Andrew O’Neil 54.

The survey tracks 151 species very well state-wide. 24 of these are significantly increasing in numbers and 38 are significantly declining. Greatest rates of significant declines are found in grassland, scrub and woodland habitats, neotropical migrants, and open cup & ground or lower nesters.

White-winged Dove Distribution From a Recently Colonized Town in the Coastal Prairie of Texas

Lyndon Schatz, 608 Blyth, Victoria, TX 77904

Brent Ortego, Texas Parks and Wildlife Department, 2805 N. Navarro, Suite 600B, Victoria, TX 77901

White-winged Doves (Zenaida asiatica) have been expanding their population and range in Texas from the Rio Grande Valley for the last several decades. The largest breeding population containing over 1 million birds is in San Antonio. Aside from larger urban areas being colonized, many smaller more suburban towns have been occupied by white-wings for decades. The population dynamics of these residential populations are not very well understood. The objective of this study was to determine if the white-wings spent the entire year at Victoria, and if there was any difference in survival and distribution of hatch year and adult birds. The senior author opportunistically banded 1796 white-wings from his yard in Victoria during 10 of 11 breeding season from 1995 through 2005. 49 birds were recaptured at the banding station and 44 were harvested by hunters. No foreign recaptures were obtained from this project, but 19 of 44 birds harvested were from distances greater than 50 miles. Six of these were harvested >100 miles and occurred at sites like San Antonio, Mexico, Guatemala and Florida. Adults had a greater tendency to be recaptured/harvested, 8.5% of 520, than young white-wings, 3.8% of 1276; P<.05.

Banding

White-winged Doves were opportunistically banded as they came in to feed at a permanent ground bird feeding station in the north side of Victoria, Texas, from March through September from 1995 thru 2004, with 1996 having no banding. Two standard walk-in traps were used for l hour each banding day from 1995 thru 2000. Starting in 2001, a drop trap (8 X 3 X 1- foot) was fabricated using 1.25-inch PVC pipe for framing and 1.5 inch bar mesh netting for walls, and was used to diversify the trapping methods. Trap shy birds appeared to be more vulnerable to capture by alternating the capture technique. However, birds caught per day did not differ, but number of days when birds were available did.

OVERVIEW OF BANDING IN THE CONSERVATION OF PURPLE MARTINS IN SAN ANTONIO AND SOUTH TEXAS

Louise Chambers, Education Director, Purple Martin Conservation Association, 301 Peninsula Drive, Ste. 6, Erie, PA 16505; louise@purplemartin.org

John Barrow, Purple Martin Banding Coordinator-South Texas, 4146 Congressional Dr., Corpus Christi, TX 78471; barrow@chilitech.com;

Abstract: In eastern North America, Purple Martins (Progne subis) nest almost exclusively in housing provided by people. This dependency, their tractable nature, and their strong fidelity to nesting colonies, make Purple Martins ready subjects for banding based studies. An overview of the study being conducted in San Antonio and South Texas, now in its fifth year, is presented as example of what can be obtained through a concerted banding effort. Emphasis is on general biology and management of Purple Martins, migratory roost development and movement, and inclusion of educational opportunities at the elementary school level. A number of other Canadian and US banders, primarily in northern states, having similar objectives independently band and color-mark Purple Martins. Purple Martin Conservation Association promotes standardization and coordination of data, so that it can be pooled for population monitoring and studies at different geographic scales. Results could be useful in addressing regional declines and population variances of Purple Martins. The situation with Purple Martins in South Texas is presented as an example.

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