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Title: LANDCOVER CHANGE AND POPULATION DYNAMICS OF FLORIDA SCRUB-JAYS AND FLORIDA GRASSHOPPER SPARROWS.
Creator: Breininger, David, Noss, Reed, University of Central Florida
Abstract / Description: I confronted empirical habitat data (1994-2004) and population data (1988-2005) with ecological theory on habitat dynamics, recruitment, survival, and dispersal to develop predictive relationships between landcover variation and population dynamics. I focus on Florida Scrub-Jays, although one chapter presents a model for the potential influence of habitat restoration on viability of the Florida Grasshopper Sparrow. Both species are unique to Florida landscapes that are dominated by shrubs and...
Show moreI confronted empirical habitat data (1994-2004) and population data (1988-2005) with ecological theory on habitat dynamics, recruitment, survival, and dispersal to develop predictive relationships between landcover variation and population dynamics. I focus on Florida Scrub-Jays, although one chapter presents a model for the potential influence of habitat restoration on viability of the Florida Grasshopper Sparrow. Both species are unique to Florida landscapes that are dominated by shrubs and grasses and maintained by frequent fires. Both species are declining, even in protected areas, despite their protected status. I mapped habitat for both species using grid polygon cells to quantify population potential and habitat quality. A grid cell was the average territory size and the landcover unit in which habitat-specific recruitment and survival occurred. I measured habitat-specific recruitment and survival of Florida Scrub-Jays from 1988-2008. Data analyses included multistate analysis, which was developed for capture-recapture data but is useful for analyzing many ecological processes, such as habitat change. I relied on publications by other investigators for empirical Florida Grasshopper Sparrow data. The amount of potential habitat was greatly underestimated by landcover mapping not specific to Florida Scrub-Jays. Overlaying east central Florida with grid polygons was an efficient method to map potential habitat and monitor habitat quality directly related to recruitment, survival, and management needs. Most habitats for both species were degraded by anthropogenic reductions in fire frequency. Degradation occurred across large areas. Florida Scrub-Jay recruitment and survival were most influenced by shrub height states. Multistate modeling of shrub heights showed that state transitions were influenced by vegetation composition, edges, and habitat management. Measured population declines of 4% per year corroborated habitat-specific modeling predictions. Habitat quality improved over the study period but not enough to recover precariously small populations. The degree of landcover fragmentation influenced mean Florida Scrub-Jay dispersal distances but not the number of occupied territories between natal and breeding territories. There was little exchange between populations, which were usually further apart than mean dispersal distances. Florida Scrub-Jays bred or delayed breeding depending on age, sex, and breeding opportunities. I show an urgent need also for Florida Grasshopper Sparrow habitat restoration given that the endangered bird has declined to only two sizeable populations and there is a high likelihood for continued large decline. A major effect of habitat fragmentation identified in this dissertation that should apply to many organisms in disturbance prone systems is that fragmentation disrupts natural processes, reducing habitat quality across large areas. Humans have managed wildland fire for > 40,000 years, so it should be possible to manage habitat for many endangered species that make Florida's biodiversity unique. This dissertation provides methods to quantify landscape units into potential source and sink territories and provides a basis for applying adaptive management to reach population and conservation goals.
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Date Issued: 2009
Identifier: CFE0002537, ucf:47638
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002537

Title: HATCHING ASYNCHRONY OCCURS AS A BYPRODUCT OF MAINTAINING EGG VIABILITY.
Creator: Aldredge, Robert, Noss, Reed, University of Central Florida
Abstract / Description: For many organisms, embryonic development begins directly after an egg (ovum) has been fertilized by sperm; however, some organisms delay the onset of embryonic development until conditions are favorable for raising young. This delayed onset of development could occur by delaying implantation of fertilized ovum on the uterine wall, as seen in many mammals. Birds delay embryonic development by laying a set of fertilized ova over a period of consecutive days. These fertilized ova are protected...
Show moreFor many organisms, embryonic development begins directly after an egg (ovum) has been fertilized by sperm; however, some organisms delay the onset of embryonic development until conditions are favorable for raising young. This delayed onset of development could occur by delaying implantation of fertilized ovum on the uterine wall, as seen in many mammals. Birds delay embryonic development by laying a set of fertilized ova over a period of consecutive days. These fertilized ova are protected from the ambient environment by an exterior shell, and it is in this shell outside of the female's body that embryonic development occurs, but only when females initiate incubation. The number of fertilized ova (eggs) that can be laid by a single female in a single clutch varies among and within bird species, and understanding this variation remains a vital, unanswered question in ornithology. A latitudinal gradient in clutch size is widely recognized, but the reason for this pattern is unclear. Some birds lay relatively large clutches over many days, thus we should expect that eggs could withstand fairly long exposure to ambient temperature and remain viable. However, recent evidence suggests that egg viability declines with increased exposure to ambient temperatures. The egg viability hypothesis predicts that eggs will fail to hatch if exposed to warm ambient temperatures for prolonged periods. I conducted a natural experiment to determine whether egg viability can explain site-specific variation in hatching failure. Hatching failure is higher in a suburban population of Florida Scrub-Jays than it is in a wildland population, possibly because suburban scrub-jays lay larger clutches. Scrub-jays, like many bird species, lay one egg per day and begin incubation with the last-laid egg, thus first-laid eggs in the larger suburban clutches should be exposed to the warm ambient temperatures of sub-tropical Florida longer than first-laid eggs in the smaller clutches typical of the wildland population. As predicted, I found hatching failure is higher in first-laid eggs in the suburbs, and these eggs experience increased exposure to warm ambient temperatures. At both sites, females appear to begin incubation earlier in the laying period as ambient temperatures increase seasonally, possibly to minimize exposure to warm ambient temperatures and minimize hatching failure in first-laid eggs. However, early onset of incubation causes eggs to hatch asynchronously (> 24 hours between the first and last-hatched egg), and hatching asynchrony increases within-brood size-asymmetries, which leads to an increased frequency of brood reduction (the nonrandom loss of last-hatched young because of starvation). Thus, a tradeoff may exist between beginning incubation earlier in the laying period to minimize hatching failure in first-laid eggs and delaying the onset of incubation to minimize hatching asynchrony and brood reduction. This tradeoff can have profound effects on avian clutch sizes, and may potentially explain the widely known negative relationship between latitude and clutch size.
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Date Issued: 2008
Identifier: CFE0002473, ucf:47706
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002473

Title: EFFECTS OF PATCH SIZE AND MATRIX TYPE ON BIRD ASSEMBLAGES WITHIN CENTRAL FLORIDA CYPRESS DOMES.
Creator: Noran, Julia, Noss, Reed F., University of Central Florida
Abstract / Description: The numerous studies on the effects of patch size on bird assemblages have produced varied results. I studied the effects of patch size and surrounding matrix on bird assemblages within central Florida cypress domes. My null hypothesis was that bird assemblages within cypress domes are unaffected by dome size or development in the matrix around the dome. My alternative hypothesis was that differences in bird assemblages are correlated with size and the degree of development within the matrix....
Show moreThe numerous studies on the effects of patch size on bird assemblages have produced varied results. I studied the effects of patch size and surrounding matrix on bird assemblages within central Florida cypress domes. My null hypothesis was that bird assemblages within cypress domes are unaffected by dome size or development in the matrix around the dome. My alternative hypothesis was that differences in bird assemblages are correlated with size and the degree of development within the matrix. I classified a pool of over a thousand domes according to three size categories and four matrix types. Three representatives for each combination of size and matrix were spot mapped for birds from May through August 2005. I examined the relationship of species richness and bird guilds to patch size and surrounding matrix. I also measured a series of potential covariates for each dome to account for variation among the three size-matrix representatives for each combination. Richness and abundance counts were divided by the number of listening points to standardize the data by effort. I found that the standardized species richness of bird assemblages significantly increased with the patch size of cypress domes; however, matrix and the interaction effect of size and matrix on overall standardized species richness were not significant. Significant covariates included percent of the buffer undeveloped, percent herbaceous cover, and the number of listening points per unit area. A linear regression tested for significant effects of log area and matrix on standardized species richness. Matrix was not significant, but log area did have a significant effect on standardized species richness. The MANOVA tests for guild richness data indicated no significant effects of dome size, matrix, or their interaction effect on diet, foraging, or location guilds. There were no significant main or interaction effects on any individual guilds in the ANOVA output. Individual backward linear regressions done on each guild indicated that matrix did not have significant effects on any guild, but log area had significant effects on ground foragers, lower-canopy foragers, omnivores, herbivores, and edge species. I then investigated the effects of size and matrix on standardized guild abundance. Dome size and matrix significantly effected diet guild abundance, but the size-matrix interaction did not. Dome size significantly affected insectivores, omnivores, and carnivores. Matrix had a significant effect on omnivores, herbivores, and carnivores. The size and matrix interaction had a significant effect on carnivores. Dome size and matrix significantly affected foraging guild abundance, but the size-matrix interaction did not. Dome size significantly affected ground, lower- and upper-canopy foragers. Matrix had a significant effect on ground, water, and upper-canopy foragers. The size and matrix interaction was not significant for any foraging guild. Dome size and matrix significantly effected location guild abundance, but the size-matrix interaction did not. Dome size significantly affected edge and interior species. Matrix had a significant effect on edge and interior species. The size and matrix interaction was not significant for any location guild. The relationship between species richness and habitat area is well-documented, and the results of this study were consistent with the expectation of higher species richness in larger areas. If maintaining high species richness is the sole goal of conservationists, then large habitat fragments would be preferable regardless of surrounding matrix. Nevertheless, species richness alone is not informative of the potential effects of patch size and matrix on the composition of an avian assemblage. Guild analysis gives insight into community structure and should be considered in addition to simple measures of species richness. Patch size and matrix type significantly affected a number of guilds, and several factors could contribute to the observed differences in guilds across patch size categories and matrix types. Different habitats are available to birds in domes of each size class and matrix type. The potential for diverse foraging opportunities increases as domes increase in size and change in relation to their surrounding matrix. A more detailed analysis is needed to determine how differences in vegetation of domes and surrounding matrix affect guilds, members of which may use habitats both within domes and the matrix. Cypress domes in the central Florida area face severe alteration or destruction due to rapid development. Long-term research that focuses on domes before and after development is needed to understand how changes in the matrix or size of the domes affect all resident flora and fauna. A variety of taxa and biogeochemical processes should be researched. Domes are naturally highly variable in size, shape, and structure, and development changes all of these characteristics. Conservation biologists and managers urgently need to determine how development affects cypress domes and what can be done to maintain their characteristic biodiversity.
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Date Issued: 2006
Identifier: CFE0001010, ucf:46842
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001010

Title: THE DISTRIBUTION, ABUNDANCE, AND HABITAT USE OF THE BIG CYPRESS FOX SQUIRREL, (SCIURUS NIGER AVICENNIA).
Creator: Munim, Danielle, Noss, Reed, University of Central Florida
Abstract / Description: Human population growth and development reduce the area and quality of natural communities and lead to a reduction of populations of the species associated with them. Certain species can be useful indicators or "focal species" for determining the quality of ecosystem remnants and the required management practices. Tree squirrels are good models for studies on the effects of fragmentation because they depend on mature forests. The Big Cypress fox squirrel, (Sciurus niger avicennia), a state...
Show moreHuman population growth and development reduce the area and quality of natural communities and lead to a reduction of populations of the species associated with them. Certain species can be useful indicators or "focal species" for determining the quality of ecosystem remnants and the required management practices. Tree squirrels are good models for studies on the effects of fragmentation because they depend on mature forests. The Big Cypress fox squirrel, (Sciurus niger avicennia), a state-listed Threatened subspecies endemic to south Florida, appears sensitive to habitat fragmentation and fire regime. This research aims to assess the conservation status of the Big Cypress fox squirrel. I documented the current distribution of the fox squirrel by obtaining and mapping occurrence records and through interviews with biologists and other field personnel of public land-managing agencies, and private landowners including golf course managers. Transect sampling was used to survey and sample natural areas and private lands to evaluate the distribution, abundance, and habitat use of fox squirrels. Natural areas and suburban areas appear to support Big Cypress fox squirrels, but individuals are widely distributed and only found in low numbers throughout southwest Florida. The distribution of fox squirrel populations depends on land use and understory height, but not the size of trees. Fire suppression has resulted in a dense understory in large portions of parks and preserve lands, which is unsuitable for fox squirrels.
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Date Issued: 2008
Identifier: CFE0002276, ucf:47838
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002276

Title: FACTORS AFFECTING BREEDING TERRITORY SIZE AND PLACEMENT OF THE FLORIDA GRASSHOPPER SPARROW (AMMODRAMUS SAVANNARUM FLORIDANUS).
Creator: Aldredge, Jill, Noss, Reed, University of Central Florida
Abstract / Description: For most taxa, maximizing fitness depends on maintaining access to adequate resources. Territories provide exclusive use of resources for an individual or a family group, thus facilitating successful reproduction. The economic defensibility of a territory depends on the quality, abundance, and distribution of its resources as well as the amount of competition that an individual must endure to maintain exclusive access. The benefits of defense must outweigh the costs for territoriality to be...
Show moreFor most taxa, maximizing fitness depends on maintaining access to adequate resources. Territories provide exclusive use of resources for an individual or a family group, thus facilitating successful reproduction. The economic defensibility of a territory depends on the quality, abundance, and distribution of its resources as well as the amount of competition that an individual must endure to maintain exclusive access. The benefits of defense must outweigh the costs for territoriality to be profitable. Territory owners may benefit from territories with high quality resources, but they also may incur greater costs defending these resources from competitors. In contrast, territories with poor quality resources provide fewer benefits to an owner but also may have fewer competitors vying for those resources. Resource quality may change over time, especially in habitats in which periodic ecological disturbances, such as fire, occur. As a result, the cost-benefit equation of defensibility also changes over time. The Florida Grasshopper Sparrow (Ammodramus savannarum floridanus), an Endangered subspecies, is a habitat specialist endemic to the Florida dry prairie, a pyrogenic ecosystem found only in south-central Florida. As a result A. s. floridanus has evolved with frequent fires and its demography is strongly influenced by the structural habitat characteristics, such as sparse woody vegetation and large amounts of bare ground that occur with frequent fire. The objective of my study was to determine what factors associated with fire (i.e. habitat structure and prey abundance) affected the "decisions" of male A. s. floridanus to defend a territory. I hypothesized that fire and the resources resulting from fire would have an impact on territory size and placement. I predicted that territories in more recently burned habitat would be of higher quality and that sparrows would avoid areas with a longer time since fire. I conducted my study at Kissimmee Prairie Preserve State Park in Okeechobee County, FL. One half of my 100-ha study plot had experienced two growing seasons since the last fire and the remaining half had experienced only a single growing season since fire at the start of my study. I mapped territories of all males within my study plot twice over the breeding season; once during the early season (nest building and incubation) and once during the late season (nestling and fledgling stages). In addition, during each survey I collected arthropods and surveyed vegetation composition within territories and at random, unoccupied points within the study plot. I compared the differences between the habitat characteristics of territories and unoccupied areas, the differences between the territories of the males that occupied the two-year rough and those in the one-year rough, males that abandoned their territories mid-season and those that remained in the study plot, and the seasonal changes in territory characteristics between the early and late season territories of males that persisted. My results indicate that A. s. floridanus selects certain habitat characteristics in which to place territories. Males preferred areas with fewer shrubs and more bare ground, which is consistent with previous studies. Prey biomass did not differ between territories and unoccupied areas. Nonetheless, although the mean mass of individual arthropods was larger in unoccupied areas, the numerical abundance of orthopterans, damselflies, and spiders was significantly higher in territories than in unoccupied areas. Sparrows were more likely to abandon their territories if they occurred in the two-year rough as opposed to the one-year rough. Territories in the two-year rough were significantly larger, had poorer quality habitat, and tended to have less prey than those in the one-year rough. The sparrows that persisted throughout the season significantly increased their territory size in the late season; however, very little spatial shift occurred, suggesting that they merely increased their territory size rather than moved to new sites. Early-season territories in the one-year rough were completely exclusive, but late season territories showed considerable overlap, suggesting lack of defense and a shift toward home ranges as opposed to exclusive territories. The habitat quality in late-season territories decreased (more shrubs, less bare ground) from the early season. Unexpectedly, however, the biomass of prey increased. This increase coincides with an increased demand for prey because sparrows are provisioning young. It seems likely that the costs of defense increase at this time because time and energy spent in defense come at the expense of time spent provisioning young. Because prey increases in the late season, the need to defend exclusive territories may decline.
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Date Issued: 2009
Identifier: CFE0002766, ucf:48135
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002766

Title: Flying under the LiDAR: relating forest structure to bat community diversity.
Creator: Butterfield, Anna, Weishampel, John, Noss, Reed, King, Joshua, University of Central Florida
Abstract / Description: Bats are important to many ecological processes such as pollination, insect (and by proxy, disease) control, and seed dispersal and can be used to monitor ecosystem health. However, they are facing unprecedented extinction risks from habitat degradation as well as pressures from pathogens (e.g., white-nose syndrome) and wind turbines. LiDAR allows ecologists to measure structural variables of forested landscapes with increased precision and accuracy at broader spatial scales than previously...
Show moreBats are important to many ecological processes such as pollination, insect (and by proxy, disease) control, and seed dispersal and can be used to monitor ecosystem health. However, they are facing unprecedented extinction risks from habitat degradation as well as pressures from pathogens (e.g., white-nose syndrome) and wind turbines. LiDAR allows ecologists to measure structural variables of forested landscapes with increased precision and accuracy at broader spatial scales than previously possible. This study used airborne LiDAR to classify forest habitat/canopy structure at the Ordway-Swisher Biological Station (OSBS) in north central Florida. LiDAR data were acquired by the National Ecological Observatory Network (NEON) airborne observation platform in summer 2014. OSBS consists of open-canopy pine savannas, closed-canopy hardwood hammocks, and seasonally inundated basin marshes. Multiple forest structural parameters (e.g., mean, maximum, and standard deviation of canopy height) were derived from LiDAR point clouds using the USDA software program FUSION. K-means clustering was used to segregate each 5x5 m raster across the ~3765 ha OSBS area into six different clusters based on the derived canopy metrics. Cluster averages for maximum, mean, and standard deviation of return heights ranged from 0 to 19.4 m, 0 to 15.3 m, and 0 to 3.0 m, respectively. To determine the relationships among these landscape-canopy features and bat species diversity and abundances, AnaBat II bat detectors were deployed from May to September in 2015 stratified by these distinct clusters. A statistical regression model selection approach was performed in order to evaluate how forest structural attributes such as understory clutter, vertical canopy structure, open and closed canopy, etc. and landscape metrics influence bat communities. The most informative models showed that a combination of site-specific (e.g., midstory clutter and entropy) and landscape level attributes (e.g., area of water and service road length) contributed to bat community patterns. This knowledge provides a deeper understanding of habitat-species interactions to better manage survival of these species and provides insight into new tools for landscape management as they apply to specific species.
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Date Issued: 2016
Identifier: CFE0006177, ucf:51151
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006177

Title: The behavior of humans and wildlife with respect to roads: insights for mitigation and management.
Creator: Grace, Molly, Noss, Reed, Weishampel, John, Hoffman, Eric, Johnson, Steve, University of Central Florida
Abstract / Description: Road ecology is the study of how roads and wildlife interact. Traditionally, road ecologists have primarily focused on one effect of roads: roadkill. Though roadkill can have devastating effects on wildlife populations, roads have sub-lethal impacts that are gaining more and more attention from the scientific community. These sub-lethal impacts include noise, light, and chemical pollution as well as altered habitat structure, which can all influence animal behavior. In this dissertation, I...
Show moreRoad ecology is the study of how roads and wildlife interact. Traditionally, road ecologists have primarily focused on one effect of roads: roadkill. Though roadkill can have devastating effects on wildlife populations, roads have sub-lethal impacts that are gaining more and more attention from the scientific community. These sub-lethal impacts include noise, light, and chemical pollution as well as altered habitat structure, which can all influence animal behavior. In this dissertation, I applied a behavioral ecology framework to study specific lethal and sub-lethal road effects with the goal of improving mitigation efforts. In Chapters 1 and 2, I evaluated how human behavior may be modified to reduce wildlife-vehicle collisions; traditionally efforts have been made to modify wildlife road crossing behavior. I found that Roadside Animal Detection Systems, which warn drivers when animals are near the road, are successful in reducing crash risk; however, care must be taken to ensure that drivers do not become acclimated to the warning system. In Chapters 3 and 4, I evaluated how traffic noise affects subadult growth and adult abundance and communication of anuran amphibians (frogs and toads), a taxon widely recognized as one of the most negatively impacted by roads. I found that through traffic noise alters tadpole behavior, it does not appear to have a negative effect on their growth. Traffic noise does, however, negatively affect adult anuran abundance. My results indicate that this reduction in abundance is caused by the interference of traffic noise with anuran communication.
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Date Issued: 2017
Identifier: CFE0006595, ucf:51275
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006595

Title: From pet to pest? The potential global range and food web effects of a generalist carnivore.
Creator: Bevan, Hannah, Jenkins, David, Noss, Reed, Campbell, Todd, University of Central Florida
Abstract / Description: The Nile monitor lizard [Varanus niloticus (Linnaeus, 1766)] is a generalist carnivore, native to Sub-Saharan Africa and the Nile River but now established in North America as a result of the pet trade. Once introduced, they are a potential invasive threat to native wildlife. Here, I create ensemble species distribution models (SDMs) to predict the global distribution of this generalist carnivore given current and future climate conditions. I then quantify the monitor's potential effects on...
Show moreThe Nile monitor lizard [Varanus niloticus (Linnaeus, 1766)] is a generalist carnivore, native to Sub-Saharan Africa and the Nile River but now established in North America as a result of the pet trade. Once introduced, they are a potential invasive threat to native wildlife. Here, I create ensemble species distribution models (SDMs) to predict the global distribution of this generalist carnivore given current and future climate conditions. I then quantify the monitor's potential effects on 85 food webs representing (>)900 different species within the projected regions based on stomach content data. Climate, vegetation, and elevation data are used for 507 georeferenced observation points from the Nile monitor's native range to produce current and future (2070) ensemble SDMs. Explanatory variables are evaluated as ten alternative models organized in three subsets according to model assumptions. The true skill statistic (TSS), sensitivity, and specificity were used to assess model performance, and the best subset was averaged to represent an ensemble model. Food web impacts after the generalist predator's addition are determined by changes in nine metrics of food web structure. The most predictive (TSS scores ?0.87) ensemble SDM was based on the MARS and FDA algorithms using elevation and climate for current and future conditions. This model shows that, if introduced, Nile monitors will likely spread into many regions in the Americas, the Caribbean, Madagascar, Southeast Asia, and Australia. Assuming unabated carbon emissions by 2070, climate change will enhance that potential range. Adding Nile monitors to food webs generally increases overall trophic links, connectance, link density, and fraction of intermediate taxa, with decreases in the fraction of top and basal taxa. These results are consistent with a generalist predator that affects many species and is likely to affect food web stability. The potential Nile monitor range is vast and encompasses multiple biodiversity hotspots. Given many strong food web interactions by this generalist predator, vulnerable regions should actively prohibit/regulate Nile monitors as pets, enforce those restrictions, and promote exotic pet amnesty programs. Southern US states should especially act soon to prevent spread of the Nile monitor to the Neotropics from its current introduced population in Florida and as released pets.
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Date Issued: 2016
Identifier: CFE0006441, ucf:51446
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006441

Title: Estimated diets, diet overlap, and winter habitat associations of four grassland sparrows in Florida dry prairie.
Creator: Korosy, Marianne, Noss, Reed, Quintana-Ascencio, Pedro, Roth, James, Hinkle, Ross, Bowman, Reed, University of Central Florida
Abstract / Description: North American grassland birds show long-term population declines that generally exceed the declines of other bird groups. Efforts to conserve grassland birds require knowledge of diet and habitat requirements during both the breeding and nonbreeding periods of annual life cycles. This dissertation investigated sparrow habitat associations within two defined plant communities of the dry prairie ecosystem, the dry-mesic and wet-mesic prairie, for four prescribed fire treatments over two...
Show moreNorth American grassland birds show long-term population declines that generally exceed the declines of other bird groups. Efforts to conserve grassland birds require knowledge of diet and habitat requirements during both the breeding and nonbreeding periods of annual life cycles. This dissertation investigated sparrow habitat associations within two defined plant communities of the dry prairie ecosystem, the dry-mesic and wet-mesic prairie, for four prescribed fire treatments over two consecutive winters. Grasshopper and Henslow's sparrows showed higher relative abundance in wet-mesic prairie and Bachman's Sparrows were more abundant in dry-mesic prairie across all fire treatments. Abundances of Grasshopper and Bachman's sparrows were best predicted by plant community association and secondly by time since fire; whereas for Henslow's Sparrows, habitat and time since fire were equally important. Fall molt-period diets and diet overlap were modeled for resident Florida Grasshopper and Bachman's sparrows using stable carbon and nitrogen isotope ratios of bird feathers and potential food sources, e.g., arthropods and seeds. Grasshoppers (Orthoptera, including a variety of species foraging on both C3 and C4 herbs), spiders, dragonflies, flies, beetles and weevils comprised the majority of the diets of adult and juvenile Florida Grasshopper Sparrows and Bachman's Sparrows, but in differing proportions. Despite the similarity in reconstructed diets for the two sparrow species, analysis of diet overlap suggested that approximately half of the Florida Grasshopper Sparrows had diets consisting of higher trophic level prey than Bachman's Sparrows. Winter diets and diet overlap among Grasshopper, Henslow's, and Bachman's sparrows were reconstructed using stable carbon and nitrogen isotope ratios of feathers and potential arthropod and seed food sources. Sparrows were captured and recaptured in winter 2007-2008 using systematic flush-netting, removing a tail feather at first capture and then removing the regrown feather when birds were recaptured. Winter diets of all three sparrows included a variety of arthropods, grass seeds, and sedge seeds, but Bachman's Sparrow winter diets spanned greater trophic diversity than either of the migratory sparrows. Estimated diets of Henslow's and Grasshopper sparrows differed from that of Bachman's Sparrow but Henslow's Sparrow diets did not differ from Grasshopper Sparrow diets. This is the first study of fall and winter sparrow diets in Florida based on stable isotopes and the first study in peninsular Florida on habitat associations of ground-dwelling sparrows.
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Date Issued: 2013
Identifier: CFE0005363, ucf:50475
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005363

Title: Juvenile Ornamentation: Its Evolution, Genetic Basis, and Variation Across Habitats.
Creator: Tringali, Angela, Noss, Reed, Bowman, Reed, Fauth, John, Fedorka, Kenneth, University of Central Florida
Abstract / Description: Ornamental traits are considered honest advertisements of fitness, and their evolution is usually explained in terms of sexual selection. This explanation remains unsatisfactory in some instances, for example, juvenile birds whose plumage is molted prior to adulthood and breeding. I first evaluate whether juvenile plumage reflectance signals dominance status in the Federally Threatened Florida scrub-jay (Aphelocoma coerulescens) using a combination of observational and experimental methods....
Show moreOrnamental traits are considered honest advertisements of fitness, and their evolution is usually explained in terms of sexual selection. This explanation remains unsatisfactory in some instances, for example, juvenile birds whose plumage is molted prior to adulthood and breeding. I first evaluate whether juvenile plumage reflectance signals dominance status in the Federally Threatened Florida scrub-jay (Aphelocoma coerulescens) using a combination of observational and experimental methods. Then I estimate the heritability, non-genetic maternal and environmental effects, and strength of selection on juvenile plumage reflectance using archived feather samples and a pedigree constructed from historical nest records. Finally, I compare plumage reflectance and its use as a signal between a wildland and suburban population of scrub-jays. I conclude that plumage reflectance is a signal of dominance, and that social selection can also drive the evolution of sexually dimorphic traits. In this species, plumage reflectance is heritable and influenced by maternal effects, but environmental effects are inconsequential. Although this trait appears to have an important function, only mean brightness and female hue are associated with lifetime reproductive success. Plumage reflectance was more UV-shifted in the suburban birds, but there is no reason to believe that urbanization decreases the value of this plumage as a signal. However, these plumage differences may facilitate dispersal from suburban areas, contributing to the decline of suburban populations.
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Date Issued: 2013
Identifier: CFE0005431, ucf:50413
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005431

Title: Cross-Continental Insights into Jaguar (Panthera onca) Ecology and Conservation.
Creator: Figel, Joseph, Noss, Reed, Quintana-Ascencio, Pedro, Jenkins, David, Quigley, Howard, University of Central Florida
Abstract / Description: The jaguar (Panthera onca) is a widely distributed large carnivore and the focal species of a range-wide connectivity initiative known as the jaguar conservation network (JCN). Comprised of ~83 Jaguar Conservation Units (JCUs) and ~75 corridors from northern Mexico to Argentina, the JCN functions as a conduit for jaguar movement and gene flow. Key linkages in the network are imperiled by human population growth, large-scale agriculture, highway expansion, and other infrastructural development...
Show moreThe jaguar (Panthera onca) is a widely distributed large carnivore and the focal species of a range-wide connectivity initiative known as the jaguar conservation network (JCN). Comprised of ~83 Jaguar Conservation Units (JCUs) and ~75 corridors from northern Mexico to Argentina, the JCN functions as a conduit for jaguar movement and gene flow. Key linkages in the network are imperiled by human population growth, large-scale agriculture, highway expansion, and other infrastructural development. Labeled (")corridors of concern,(") these vulnerable linkages are imperative to the maintenance of connectivity and genetic diversity throughout jaguar distribution. I take a multi-faceted approach to analyze conservation issues and identify potential solutions in three of the most vulnerable connections of the JCN. I estimate densities and assess local residents' perceptions of jaguars in a fragmented JCU in western Mexico, analyze 3 years of data from 275 camera-trap sites to evaluate jaguar habitat use in a corridor of concern in Colombia, and quantify the umbrella value of jaguars for endemic herpetofauna in Nuclear Central America, a ~ 370,000 km(&)#178; sub-region of the Mesoamerican biodiversity hotspot. My research produces the first jaguar density estimate in a JCU containing human population densities (>)50 people/km2 and provides the strongest support for jaguar association with wetlands collected to date. In Nuclear Central America, one of the most important yet vulnerable areas of the JCN, I demonstrate the umbrella value of this wide-ranging felid. I conclude with a discussion on the need to reevaluate extirpation thresholds of jaguars in human-use landscapes, to direct more research on wetlands as keystone habitats for jaguars, and to further assess the utility of umbrella analyses using jaguars as focal species to support holistic conservation planning.
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Date Issued: 2017
Identifier: CFE0006591, ucf:51258
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006591

Title: Habitat selection in transformed landscapes and the role of novel ecosystems for native species persistence.
Creator: Sanchez Clavijo, Lina, Quintana-Ascencio, Pedro, Noss, Reed, Weishampel, John, Rodewald, Amanda, University of Central Florida
Abstract / Description: To understand native species persistence in transformed landscapes we must evaluate how individual behaviors interact with landscape structure through ecological processes such as habitat selection. Rapid, widespread landscape transformation may lead to a mismatch between habitat preference and quality, a phenomenon known as ecological traps that can have negative outcomes for populations. I applied this framework to the study of birds inhabiting landscapes dominated by forest remnants and...
Show moreTo understand native species persistence in transformed landscapes we must evaluate how individual behaviors interact with landscape structure through ecological processes such as habitat selection. Rapid, widespread landscape transformation may lead to a mismatch between habitat preference and quality, a phenomenon known as ecological traps that can have negative outcomes for populations. I applied this framework to the study of birds inhabiting landscapes dominated by forest remnants and shade coffee plantations, a tropical agroforestry system that retains important portions of native biodiversity. I used two different approaches to answer the question: What is the role of habitat selection in the adaptation of native species to transformed landscapes? First, I present the results of a simulation model used to evaluate the effects of landscape structure on population dynamics of a hypothetical species under two mechanisms of habitat selection. Then I present the analyses of seven years of capture-mark-recapture and resight data collected to compare habitat preference and quality between shade coffee and forest for twelve resident bird species in the Sierra Nevada de Santa Marta (Colombia). I provide evidence for the importance of including the landscape context in the evaluation of ecological traps and for using long-term demographic data when evaluating the potential of novel ecosystems and intermediately-modified habitats for biodiversity conservation. Beyond suggestions to improve bird conservation in shade coffee, my findings contribute to theory about ecological traps and can be applied to understand population processes in a wide variety of heterogeneous landscapes.
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Date Issued: 2016
Identifier: CFE0006494, ucf:51392
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006494

Title: Physiological Constraints on Warm-Water Habitat Site Selection and Utilization by the Florida Manatee (Trichechus manatus latirostris) in East Central Florida.
Creator: Spellman, Ann, Worthy, Graham, Noss, Reed, Hinkle, Ross, DeFreese, Duane, University of Central Florida
Abstract / Description: Living at the northern limits of its geographic range, the Florida manatee is particularly susceptible to cold stress-related mortality during the winter months, with most deaths occurring in the lower two-thirds of the state. Contributing to this cold stress susceptibility is the manatee's limited physiological and behavioral responses available when thermally stressed. While capable of migrating south in response to falling water temperatures, manatees must still find warm water when...
Show moreLiving at the northern limits of its geographic range, the Florida manatee is particularly susceptible to cold stress-related mortality during the winter months, with most deaths occurring in the lower two-thirds of the state. Contributing to this cold stress susceptibility is the manatee's limited physiological and behavioral responses available when thermally stressed. While capable of migrating south in response to falling water temperatures, manatees must still find warm water when ambient river temperature drops below 20(&)deg;C for more than a few days. This is in part due to the species low metabolic rate, limited capacity for thermogenesis, and limited ability to raise its metabolic rate. Prolonged exposure to cold temperatures may result in cold stress syndrome, which involves a number of potentially life-threatening, if not fatal physiological changes. Survival during the winter months is therefore, dependent upon the manatee's ability to balance basic physiological needs, primarily the need to forage and to obtain fresh water with the need to stay warm.When identifying which animals are most susceptible and where, analyses of statewide manatee mortality records from 1996 through 2011 (n = 823) indicated that, size and location matter. Medium to large-sized calves accounted for the majority of documented death from cold stress (46.6%), while subadults and small calves were the least represented size classes (14.3 % and 9.5%, respectively). Adults slightly outnumbered subadults (15.8%). Males outnumbered females in all size classes but gender differences were not statistically significant. With regards to location, two areas of the state, the southwest and central east coasts showed the highest incidents of cold stress-related mortality. Both are regions with no primary, natural warm-water springs and whose principal warm-water refugia are power plant effluents. Brevard County on the central east coast is the area most at risk during cold weather events accounting for more than 25% of all cold stress deaths statewide. Warm-water sites within this region are few and relatively underrepresented in the literature in an area well-studied in terms of manatee abundance and distribution relative to the operational power plant. Results from cold stress data analyses emphasize the importance of identifying and characterizing the physical attributes of both known and suspected secondary warm-sites used by manatees in this region for both long and short term protection of the species, and its critical habitat.Three locations within Brevard County identified as passive thermal basins (PTBs), and classified as secondary warm-water sites, have been documented supporting in excess of 100 manatees on numerous occasions, and during winters of varying severity. Unique in physical appearance, distance to forage, hydrology including thermal profiles, and when it was used by manatees, each site challenged the accepted definitions and criteria of what constitutes an acceptable and appropriate warm-water site.Through analyses of photo-identification records, site fidelity at two of these warm-water sites, the Berkeley Canal and the Desoto Canal, was established for a minimum of 20 highly identifiable animals, 15 of which used adjacent sites within the same year, and 6 that used both sites but during different years. Observations of daily use patterns within the sites supported optimization of thermoregulation through adjustments in both vertical and horizontal movement, the latter of which seemed to follow the path of the sun. Manatees using the sites also made use of bottom sediment presumably to stay warm at all three locations. Temperature data indicated that water temperatures monitored in the sediment at secondary sites were some of the highest in the county. The predictable movements during all but the coldest weather fronts indicated that manatees utilized these sites during the early morning and afternoon hours when ambient river temperatures were coldest, gradually returning to the river to feed as ambient temperatures began to rise later in the afternoon.The availability of PTBs in proximity to primary warm-water sites within the region may provide an important component needed for manatees to successfully balance the need to forage with the need to stay warm by providing a network that allows for more efficient foraging while reducing exposure to sub-critical ambient river temperatures. The challenge of balancing the need to forage and to maintain homeostasis in the face of thermal stress is complex. This complexity was best approached and better understood through use of a manatee energetics model. The model was designed to facilitate simulation of an unlimited number of different case scenarios involving the exposure of virtually created manatees to a variety of winter conditions as might be experienced by real manatees in a natural system. Sixty-four different simulations were run using six virtual manatees of differing ages, gender, physical parameters, and knowledge of warm-water sites. Simulations were conducted using actual winter water temperature data from Brevard secondary sites and the ambient river from both a mild and a severe winter season. Outcomes, measured as changes in physical parameters indicative of body condition (i.e. mass, percent body fat, blubber depth, girths, etc.), showed that all else being equal, calves in the 2 year-old range fared poorly in all scenarios when compared to individuals of larger size. Subadults fared better than larger adults. This outcome illustrates the complex relationship between size, energy requirements and the synergistic effects of body mass, body fat and blubber thickness on SA:V ratio. Model outcomes agree closely with manatee cold stress mortality analyses predicting that medium to large-sized calves are most susceptible to CS, followed by adults, then subadults.Because all models are simplifications of complex systems, the manatee energetics model is not without its flaws and limitations. The current version of the model could not predict the point at which cold stress mortality would occur. However, a cold stress warning system incorporated into the design alerts the user if potential CSS is likely based on changing physical parameters. Another limitation was the inability of the model to account for the behavioral plasticity of individual subjects since virtual manatees respond to water temperatures based on the user defined rules. A number of additional limitations related to gaps in existing manatee data the gaps were identified and defined. Despite these gaps, the model is designed to allow for incorporation of additional interactions, feedback loops and relevant data as it becomes available and as additional physiological interactions and energy requirements are more clearly defined. Sensitivity analyses, a feature of the model that allowed for modifications in a number of physical as well as environmental parameters, provided an otherwise unlikely opportunity to see how incremental changes in input values, specifically the starting values for mass, percent body fat and blubber depth affected the model's outcome. Ultimately the goal of the model was to facilitate a better understanding of complex relationships by challenging our preconceived understanding of the manatee and its environment
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Date Issued: 2014
Identifier: CFE0005419, ucf:50428
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005419

Title: Florida Local Government Conservation Planning: Variability, Drivers, and Policy Implications.
Creator: Pannozzo, Pamela, Noss, Reed, Quintana-Ascencio, Pedro, Hinkle, Charles, Knox, Claire, University of Central Florida
Abstract / Description: This study examined the quality of Florida county government conservation planning. To assess conservation planning quality, a theoretical model of conservation planning as prescribed by the conservation science literature was first developed. A plan evaluation coding protocol was applied to local comprehensive plan Conservation Elements to determine the extent to which county-level conservation planning met the theoretical model. A high degree of variability in conservation planning quality...
Show moreThis study examined the quality of Florida county government conservation planning. To assess conservation planning quality, a theoretical model of conservation planning as prescribed by the conservation science literature was first developed. A plan evaluation coding protocol was applied to local comprehensive plan Conservation Elements to determine the extent to which county-level conservation planning met the theoretical model. A high degree of variability in conservation planning quality was found. Highest quality conservation planning occurred in the Gulf coast counties of southwest Florida. Lowest conservation planning quality occurred in the Florida Panhandle counties. The quality of conservation planning of coastal counties was significantly higher than that of inland counties. Significant regional differences were also found, where conservation planning quality in South Florida counties was significantly higher than conservation planning quality in Panhandle counties. Geographic differences in conservation planning quality were likely attributable to significant differences in socioeconomic variables among counties, including differences in education, wealth, and urbanization. Multiple regression analysis using an information theoretic approach was employed to develop a predictive model of conservation planning quality of Florida local governments. The two most plausible predictors in the model were education level of the public and total resources. Local and global spatial autocorrelation analysis were next applied to county conservation planning scores to investigate spatial patterns of conservation planning quality, which were found to be related to the policy process of diffusion. Lastly, current local government conservation planning policy was analyzed for effectiveness and policy recommendations were made. Improving the effectiveness of local conservation planning will require changes in statutory provisions of the state Florida Forever and Growth Management statutes. It will also require a greater commitment on the part of the state of Florida to protect the state's biological resources over the long term.
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Date Issued: 2013
Identifier: CFE0005041, ucf:49971
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005041

Title: Wetland diversity in a disturbance-maintained landscape: Effects of fire and a fire surrogate on aquatic amphibian survival and species depauperateness.
Creator: Klaus, Joyce, Noss, Reed, Quintana-Ascencio, Pedro, Jenkins, David, Dr. L. Katherine Kirkman, University of Central Florida
Abstract / Description: Disturbance is one of the central concepts explaining how diversity arises and is perpetuated in ecological time. A good model system for testing hypotheses related to disturbance is the longleaf pine ecosystem in the southeastern U.S. because in this ecosystem frequent, low-severity fires acts as a disturbance that maintains a unique vegetation structure and high species richness. Vegetation structure influences animal distributions; in fire-dependent ecosystems many animals rely on open...
Show moreDisturbance is one of the central concepts explaining how diversity arises and is perpetuated in ecological time. A good model system for testing hypotheses related to disturbance is the longleaf pine ecosystem in the southeastern U.S. because in this ecosystem frequent, low-severity fires acts as a disturbance that maintains a unique vegetation structure and high species richness. Vegetation structure influences animal distributions; in fire-dependent ecosystems many animals rely on open-structured, fire-maintained vegetation but shrubs and trees encroach into fire-dependent ecosystems where fire has been excluded. Prescribed burning and mechanical removal are commonly used as restoration tools to control encroachment. To better assess and compare the restoration potential of these tools, a more thorough understanding of how they change vegetation structure and habitat suitability for animals is necessary.The southeastern U.S. is a diversity hot-spot for amphibians, many of which require ephemeral wetlands embedded in longleaf pine uplands for the aquatic phase of their life cycle. Amphibian diversity has been declining in recent decades and habitat loss/degradation has been cited as one of the leading causes. Although often overlooked in studies of fire ecology, the ephemeral wetlands required by many amphibians are also fire-dependent habitats that have been negatively impacted by lack of fire. To understand how disturbance interacts with wetland vegetation and aquatic-phase amphibians, three disturbance treatments meant to mimic the effects of natural disturbance on vegetation structure were applied randomly to 28 dry ephemeral wetlands in the Lower Coastal Plain of South Carolina, U.S. The treatments consisted of early growing-season prescribed fire, mechanical vegetation removal (a proposed fire surrogate), and a combination of mechanical removal plus fire; some sites were left untreated for reference. Vegetation structure was quantified and amphibian assemblages were monitored before and after treatments. In addition, one species of amphibian was used in a tadpole survival experiment to examine differences in performance among treatments. Other factors that could be affected by treatments and in turn influence amphibians were measured, including water chemistry, wetland depth, quantity and quality of epilithon, and leaf litter composition.Amphibian survival was lowest, and species depauperateness highest in untreated wetlands. Depauperateness of species whose range was restricted to the range of longleaf pine was lowest in sites that had mechanical treatment plus fire. The mechanical plus fire treatment created the most open vegetation structure with lowest leaf litter accumulation, especially of hardwood litter, conditions correlated with high amphibian survival and diversity. When data from this study was combined with data from a previous study of similar nearby wetlands, a pattern emerged in which one suite of species was absent from recently burned sites, while an entirely different suite of species was absent from long-unburned sites. This evidence suggests that disturbance is related to a shift in amphibian assemblage possibly due to changes in vegetation structure and perhaps wetland ecology in general, from an algal-based system maintained by frequent fire to a detrital-based system that develops in the absence of fire.
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Date Issued: 2013
Identifier: CFE0005015, ucf:49994
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005015

Title: Landscaping Perceptions and Behaviors: Socio-ecological Drivers of Nitrogen in the Residential Landscape.
Creator: Souto, Leesa, Hinkle, Charles, Canan, Penelope, Noss, Reed, Weishampel, John, Pals, Heili, University of Central Florida
Abstract / Description: Driven by individual influences such as beliefs, attitudes, personal norms, and abilities, as well as by social influences like community norms, mandates, and the market, suburban homeowners are motivated to select and maintain a turf grass landscape. In many areas of Florida, effective suburban lawn maintenance requires regular inputs of nitrogenous fertilizer, some of which is lost to the environment, contributing to water quality degradation and ecosystem dysfunction. Reducing nitrogen...
Show moreDriven by individual influences such as beliefs, attitudes, personal norms, and abilities, as well as by social influences like community norms, mandates, and the market, suburban homeowners are motivated to select and maintain a turf grass landscape. In many areas of Florida, effective suburban lawn maintenance requires regular inputs of nitrogenous fertilizer, some of which is lost to the environment, contributing to water quality degradation and ecosystem dysfunction. Reducing nitrogen inputs to aquatic systems requires a better understanding of the links between residential landscape management and the potential for fertilizer loss. This dissertation examines the linkages between the human behaviors contributing nitrogen to the suburban landscape and the resulting environmental impacts. Framed in socio-psychological theory and social marketing research, the outcomes of this dissertation contribute much needed information to the growing realm of interdisciplinary science that expands integrative theory, develops mixed methods, utilizes spatial and temporal analyses, and conducts actionable research.
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Date Issued: 2012
Identifier: CFE0004604, ucf:49931
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004604

Florida (2)	+ -
Florida Grasshopper Sparrow (2)	+ -
disturbance (2)	+ -
fire (2)	+ -
habitat (2)	+ -

Aphelocoma coerulescens (1)	+ -
Bachman's Sparrow (1)	+ -
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Colombia (1)	+ -
Conservation planning (1)	+ -
Distribution modeling (1)	+ -
Economic defensibility (1)	+ -
Egg viability (1)	+ -
Fire (1)	+ -
Florida Scrub-Jay (1)	+ -
Florida manatee (1)	+ -
Florida scrub-jay (1)	+ -
Grasshopper Sparrow (1)	+ -
Henslow's Sparrow (1)	+ -
Mexico (1)	+ -
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Quintana-Ascencio, Pedro (5)	+ -
Weishampel, John (4)	+ -
Jenkins, David (3)	+ -

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Hinkle, Charles (2)	+ -
Hinkle, Ross (2)	+ -
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Aldredge, Robert (1)	+ -
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