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Life Sciences Commons

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Ecology

Ecology and Evolutionary Biology

Theses and Dissertations - UTB/UTPA

1996

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Full-Text Articles in Life Sciences

Using The Spot-Mapping Censusing Technique To Assess Changes In Breeding Bird Communities At Santa Ana National Wildlife Refuge, Alamo, Texas, 1940-1996, Alberto Cantu Nov 1996

Using The Spot-Mapping Censusing Technique To Assess Changes In Breeding Bird Communities At Santa Ana National Wildlife Refuge, Alamo, Texas, 1940-1996, Alberto Cantu

Theses and Dissertations - UTB/UTPA

Results of breeding-bird censuses done by Davis in 1940 and by Gehlbach between 1973-1978 at Santa Ana National Wildlife, Alamo Texas, were compared to a 1995-1996 bird survey done in Gehlbach's study area. According to the Wilcoxon rank-sum test, bird densities in 1940 and 1995-1996 were similar, while 1973-1978 densities were lower. The 1995-1996 bird community was 76% similar to both the earlier studies. However, the communities studied in 1940 and 1973-1978 had only a 60% similarity. Negligible differences in bird densities and species composition were found between the 1995 and 1996 communities. Differences are attributed to changes in vegetation …


A Comparison Of Secondary Successional Woody Vegetation In Two Revegetated Fields In South Texas And An Assessment Of Habitat Use By The Olive Sparrow, Arremonops Rufivirgatus, Patrick Grant Wright Jun 1996

A Comparison Of Secondary Successional Woody Vegetation In Two Revegetated Fields In South Texas And An Assessment Of Habitat Use By The Olive Sparrow, Arremonops Rufivirgatus, Patrick Grant Wright

Theses and Dissertations - UTB/UTPA

Aspects of plant species composition and structure of two revegetated fields in western Cameron County, Texas, were studied between 1992 and 1995. Avian habitat suitability was assessed using the Olive Sparrow, Arremonops rufivirgatus, as an indicator species. Total vegetation volume at the Longoria Wildlife Management Area (WMA), an area revegetated in 1961, was 0.745 $\rm m\sp3V/m\sp2$ and that of the Anacua WMA, revegetated in 1983-4, was 0.546 $\rm m\sp3V/m\sp2$ in 1992. Secondary woody species at the Longoria and Anacua WMA's had a Shannon's index of diversity of 0.619 and 0.264, respectively. Secondary woody vegetation at the Longoria WMA had a …