Cavity-nesting guilds are diverse communities of organisms that are hierarchically structured around the creation of and competition for tree holes as nest sites. Quantifying these communities as networks of interconnected species, or "nest webs", is a proven and efficient method for identifying important species and interactions within a cavity-nesting guild that can aid the management of these often threatened communities. Yet nest web data does not provide information regarding how natural resource managers are to encourage the support and adoption of conservation behaviors. This dissertation comprises two broad studies: one describing a cavity-nesting guild in central Namibia, and the other exploring methodology for identifying an effective flagship species for local conservation. In chapter 1, I provide background information of my study system and a review of the cavity-nesting and flagship species literature. In chapter 2, I quantify the species and resources within a cavity-nesting guild and create a cavity nest web to depict cavity creation and use in central Namibia. All cavity-nesters depended on sparse, large trees, which likely contributed to limited use of tree species across the guild. Cavity-excavators were of disparate importance for secondary cavity-nesters: important for small- and medium-bodied species but mostly unimportant for large-bodied species who depend more on large trunk hollows. In chapter 3, I describe and compare species-specific cavity resource niches among guild members to explore potential instances of cavity resource partitioning. Use of nest cavities appears to sort out by size among both cavity-excavators and secondary cavity-nesters. Excavators appear to partition cavity substrate spatially by decay class, while spatial partitioning among secondary nesters was largely by cavity type. Most interesting is the apparent temporal partitioning of large excavations among medium- and large-bodied cavity-nesters. In chapter 4, I explore a novel approach to flagship species selection that identified all previously-existing traits for flagship species, numerous traits specific to culture and personal experience, and a dozen new traits that were previously not recognized as potentially important for flagship species. This method shows considerable promise as a tool for investigating preferences for wildlife among broad stakeholders, as well as for engaging local people in wildlife conservation. / Doctor of Philosophy / Holes in trees, or cavities, are important resources for many birds, who use cavities as a safe place for raising young. Cavity-nesting birds are linked together in a cavity "nest web" based on the types of cavities used by each species. Understanding how birds are linked with each other and with certain types of cavities is critical in order to design conservation plans that preserve important community relationships. However, successful conservation also depends on strong support from local people, who are most often the people tasked with implementing the conservation actions. Flagship species can be used to gain support from necessary groups of people for specific conservation missions. This dissertation consists of two broad studies: the first study describes a community of cavity-nesting birds in Namibia, and the second explores a new way to investigate how people connect with wildlife through emotional connections. In chapter 1, I provide background information on my area of research. In chapter 2, I outline the different trees, cavities, and birds at the study site and estimate their abundance in the area. I also create a cavity nest web that illustrates the links between species. Large trees were relatively uncommon, but were important for all birds in the community. Cavities made by other birds, such as woodpeckers, were very important for small- and medium-sized species, but were mostly unimportant for large-sized species. In chapter 3, I compare the tree cavities used by different species, including the types of trees, cavities, and cavity sizes. I also explore multiple ways by which cavity-nesting birds might be dividing cavities between different species. Our most interesting finding was how medium-sized species seem to share cavities in time rather than in space; some species (i.e., small owls and woodpeckers) breed before some larger species that use the same type of cavity. Breeding early may be a way for some species to avoid competition with more competitive species, and may be the first example of this strategy being used by multiple cavity-nesters in a community. In chapter 4, I explore a new method for selecting flagship species. This method uncovered all traits that have been previously recommended for flagship species, as well as many traits specific to culture and personal experience. We also identified a dozen new traits that were previously not considered to be important for flagship species. Our new method is very promising as a tool for investigating preferences for wildlife among broad stakeholders, and for engaging and involving local people in wildlife conservation.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/115061 |
| Date | 15 May 2023 |
| Creators | Millican, David Marshall |
| Contributors | Biological Sciences, Walters, Jeffrey R., Brown, Bryan L., Dayer, Ashley A., Stanback, Mark Thomas |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf |
| Coverage | Namibia |
| Rights | Creative Commons Attribution 4.0 International, http://creativecommons.org/licenses/by/4.0/ |
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