Understanding species-habitat relationships is fundamental to the conservation of
a species. This is especially important when the species is considered endangered. The
Golden-cheeked Warbler is a habitat specialist that breeds only in oak-juniper
woodlands (considered a climax forest) of central Texas. The warbler was listed as
endangered under the federal Endangered Species Act primarily because of habitat loss
and fragmentation. Conservation measures include the preservation of existing habitat
and attempts to manage and enhance areas that once supported the warbler to return to
the climax oak-juniper woodlands. My objectives were (1) to quantify the vegetation
structure and species composition by vegetation volume of occupied warbler habitat
across the breeding range in Texas and (2) to quantify the habitat use by the warbler in
categories of behavior, substrate, height, and tree species. Instantaneous, focal animal
behavioral observations were collected for three breeding seasons at six sites across the
range of the warbler. Warbler behavior and microhabitat use were compared to
availability of vegetation volume by height class and tree species. I found that Goldencheeked
Warbler habitat varied by vegetation volume, canopy height and tree species among all sites. The warbler preferred twigs and foliage and the upper two height
classes of the habitat structure for all behaviors. Tree species use did not match
availability at any sites. The one consistent species result was the warbler used Ashe
juniper significantly less than it occurred at all sites. Other major species were used
disproportionately to the species occurrence at each site. Some tree species were used
more often than they occur in the habitat while others species were used less than they
occur in the habitat. Preferences for height class and tree species use were not
significantly influenced by vegetation volume. Some other factor not measured such as
prey availability may be the cause. Because warbler habitat characteristics and use vary
across the range, any efforts to manipulate vegetation to become habitat must consider
regional characteristics of Golden-cheeked warbler habitat.
Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-3263 |
Date | 15 May 2009 |
Creators | Newnam, John Calvin |
Contributors | Arnold, Keith A. |
Source Sets | Texas A and M University |
Language | en_US |
Detected Language | English |
Type | Book, Thesis, Electronic Dissertation, text |
Format | electronic, application/pdf, born digital |
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