Current Search: Wading birds (x)
View All Items
(1 - 8 of 8)
- Title
- A tidal inundation model of shallow-water availability (TiMSA).
- Creator
- Calle, Leonardo, Gawlik, Dale E., Xie, Zhixiao, Johnson, Brian, Graduate College
- Date Issued
- 2013-04-12
- PURL
- http://purl.flvc.org/fcla/dt/3361914
- Subject Headings
- Ecology, Wading birds, Florida Keys (Fla.)
- Format
- Document (PDF)
- Title
- A biological mechanism for enhanced wading bird foraging patches in seasonally-pulsed wetlands.
- Creator
- Faughnan, Thomas J., Gawlik, Dale E., Florida Atlantic University, Charles E. Schmidt College of Science, Center for Environmental Studies
- Abstract/Description
-
In tropical wetlands, breeding wading birds rely on concentrations of aquatic fauna during the dry season to meet increased energetic demands. Wetland microtopography increases aquatic fauna concentration levels. Crocodilians modify the landscape creating deep-water refugia but their role as a mechanism for aquatic fauna concentration is unknown. I sampled alligator (Alligator mississippiensis) abundance and slough microtopography to examine correlation between the two measures. Despite...
Show moreIn tropical wetlands, breeding wading birds rely on concentrations of aquatic fauna during the dry season to meet increased energetic demands. Wetland microtopography increases aquatic fauna concentration levels. Crocodilians modify the landscape creating deep-water refugia but their role as a mechanism for aquatic fauna concentration is unknown. I sampled alligator (Alligator mississippiensis) abundance and slough microtopography to examine correlation between the two measures. Despite increased microtopography in high alligator use sloughs, the differences were not significant. Using an in situ experimental approach, I quantified the magnitude, timing, and spatial extent of aquatic fauna concentrations within simulated alligator depressions and the surrounding marsh. Aquatic fauna density and biomass were greater within simulated depressions, thus enhancing wading bird foraging habitat. Further understanding the mechanisms creating microtopography, thus enhancing wading bird habitat, is critical to facilitate restoration and prevent declines of wading bird populations in seasonally pulsed wetlands worldwide.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013060
- Subject Headings
- Wading birds., Wetland ecology., American alligator.
- Format
- Document (PDF)
- Title
- MONITORING WADING BIRD COLONIES USING ACOUSTIC SAMPLING AND REGIONAL SHIFTS IN WADING BIRD NEST ABUNDANCES IN A PULSED WETLAND SYSTEM.
- Creator
- Larson, Rachel C., Gawlik, Dale E., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Wetland loss and degradation have led to the development of restoration programs worldwide, many of which monitor wading bird populations as indicators of wetland quality. Therefore, efficient, standardized monitoring is integral to restoration progress. I tested the use of passive acoustic monitoring to estimate nest abundances and provisioning rates in wading bird colonies and examined regional nesting dynamics in the Florida Everglades, where a long monitoring record enables analysis of...
Show moreWetland loss and degradation have led to the development of restoration programs worldwide, many of which monitor wading bird populations as indicators of wetland quality. Therefore, efficient, standardized monitoring is integral to restoration progress. I tested the use of passive acoustic monitoring to estimate nest abundances and provisioning rates in wading bird colonies and examined regional nesting dynamics in the Florida Everglades, where a long monitoring record enables analysis of nesting patterns relative to hydrologic changes. I found that call rates can serve as indices of colony nest abundances and begging call rate and timing are indicative of provisioning events. Nesting dynamics suggested that resource availability is asynchronous between regions of the Everglades, but the degree of asynchrony varies with species. The conclusions of this study will facilitate the long-term monitoring of wading bird nesting trends, which are important measures of wetland restoration in Florida and worldwide.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013771
- Subject Headings
- Wetland restoration, Wading birds, Everglades (Fla.), Acoustics
- Format
- Document (PDF)
- Title
- FORAGING ECOLOGY OF A WADING BIRD IN TIDALLY INFLUENCED HABITATS: A SEQUENTIAL MODELING FRAMEWORK.
- Creator
- Martinez, Marisa Takada, Gawlik, Dale E., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
I used empirical data to inform spatially- and temporally-explicit predictions of time-integrated habitat availability (TiHAB), quantify spatiotemporal patterns of resource selection by Little Blue Herons (Egretta caerulea), and evaluate foraging activity as function of resource availability and prey dynamics. Evaluating resource availability over time accounts for the magnitude and duration of resource change. This approach is useful for understanding mechanisms that underlie resource...
Show moreI used empirical data to inform spatially- and temporally-explicit predictions of time-integrated habitat availability (TiHAB), quantify spatiotemporal patterns of resource selection by Little Blue Herons (Egretta caerulea), and evaluate foraging activity as function of resource availability and prey dynamics. Evaluating resource availability over time accounts for the magnitude and duration of resource change. This approach is useful for understanding mechanisms that underlie resource selection in dynamic environments and for guilds that are sensitive to changes in prey availability like wading birds. I found that average TiHAB varied interannually whereby gains and losses in Little Blue Heron foraging habitat at the landscape scale (1-8 km) occurred from slight differences in annual tidal cycles otherwise imperceptible with water depth data alone. Local patterns of resource selection by Little Blue Herons were temporally consistent but spatially variable across tidally influenced environments. TiHAB was the most important habitat attribute over time and space and was superior to other environmental features and prey density as a predictor of Little Blue Heron resource selection. Foraging activity did not show a clear association with probability of resource selection, but foraging metrics were best described by changes in TiHAB consistent with changes in foraging strategy. I conclude that spatiotemporal variation in resource availability reliably predicts patterns of dynamic habitat selection and supports an energy-maximizing foraging strategy for wading birds in tidally influenced habitats. This modeling framework can be applied to quantify the spatiotemporal availability of resources in real-time or under hydrologic restoration regimes and sea level rise scenarios, and track species responses to hydrologic and other environmental fluctuations.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013925
- Subject Headings
- Ecology, Herons, Wading birds, Ecological modelling
- Format
- Document (PDF)
- Title
- Diet and Nesting Habitat of Wading Birds in a Shallow, Eutrophic Lake.
- Creator
- May, Jenna C., Gawlik, Dale E., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Avian reproductive success varies depending on environmental conditions, degree of predation, location, and food availability. I examined food availability and nesting habitat of wading birds in South Florida. Evaluating prey availability and prey used by two small heron species demonstrated the ability for small herons to maintain consistent diets through fluctuating environmental conditions, within and across different wetland types. Small herons may be able to cope with environmental...
Show moreAvian reproductive success varies depending on environmental conditions, degree of predation, location, and food availability. I examined food availability and nesting habitat of wading birds in South Florida. Evaluating prey availability and prey used by two small heron species demonstrated the ability for small herons to maintain consistent diets through fluctuating environmental conditions, within and across different wetland types. Small herons may be able to cope with environmental changes by altering foraging locations and strategies. Regarding nesting habitat, man-made sites may provide habitat comparable to natural sites, at least in the short-term. The nest’s position can influence its susceptibility to increased temperatures and predators, particularly for. Climatic conditions such as rainfall can also impact nesting success by altering foraging conditions and fish behavior. Understanding the effects of hydrologic regimes on biota can have practical applications since ecosystems around the world share similar problems with competing demands for resources, and there is a concern for how use can affect the quality of the resource.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013087
- Subject Headings
- Wading birds., Herons--Ecology., Okeechobee, Lake (Fla.)
- Format
- Document (PDF)
- Title
- Wading bird use of geographically isolated wetlands in the southeastern U.S. Coastal Plain.
- Creator
- Herteux, Camille E., Gawlik, Dale E., Smith, Lora L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Geographically isolated wetlands (GIWs) within the southeastern U.S. Coastal Plain have been increasingly recognized for their importance in providing ecosystem services. These wetlands serve as valuable foraging and breeding habitat for wetland-dependent species, including wading birds. I quantified wading bird presence in GIWs in southwestern Georgia and determined the relative importance of factors influencing their use of these wetlands. I also examined the diet of a nesting colony of...
Show moreGeographically isolated wetlands (GIWs) within the southeastern U.S. Coastal Plain have been increasingly recognized for their importance in providing ecosystem services. These wetlands serve as valuable foraging and breeding habitat for wetland-dependent species, including wading birds. I quantified wading bird presence in GIWs in southwestern Georgia and determined the relative importance of factors influencing their use of these wetlands. I also examined the diet of a nesting colony of Little Blue Herons; a species experiencing population declines throughout most of the Southeast. I found that wetland-specific parameters were important factors in predicting wading bird use of GIWs, and wading birds utilized agricultural and natural wetlands differently depending on hydrological seasonality. Little Blue Herons were primarily consuming large anurans and anuran larvae, which are characteristic of agriculturally modified wetlands. The seasonal process of receding water levels in GIWs and subsequent concentration of
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013012
- Subject Headings
- Wetlands--Georgia, Wading birds, Herons--Ecology
- Format
- Document (PDF)
- Title
- Wading Bird Foraging and Prey Concentration in the Ridge and Slough Landscape of the Everglades.
- Creator
- Binkley, Erin, Dorn, Nathan, Florida Atlantic University, Charles E. Schmidt College of Science, Center for Environmental Studies
- Abstract/Description
-
The hydrological and topographical variation of wetlands can affect the behavior, population growth, and local densities of aquatic species, which in turn can drive the behavior and density dynamics of gleaning predators. Prey availability, primarily determined by prey density and water depth in wetlands, is an important limiting factor for nesting wading bird populations, top predators in the south Florida Everglades. The Everglades is able to support large colonies of nesting wading birds...
Show moreThe hydrological and topographical variation of wetlands can affect the behavior, population growth, and local densities of aquatic species, which in turn can drive the behavior and density dynamics of gleaning predators. Prey availability, primarily determined by prey density and water depth in wetlands, is an important limiting factor for nesting wading bird populations, top predators in the south Florida Everglades. The Everglades is able to support large colonies of nesting wading birds because of the microtopographic variation in the landscape. Some types of prey concentrate in flat, shallow sloughs or become trapped in isolated pools as they move down from higher elevation ridges with receding water levels. Manipulations to the hydrology and landscape of the Everglades has negatively impacted nesting wading bird populations in the past, and may continue to be detrimental by allowing flat, shallow sloughs to be intersected by deep canals, a potential refuge for wading bird prey. In addition, the subtle elevation differences between the ridge and slough landscape may be an important mechanism for increasing slough crayfish (Procambarus fallax) prey availability for the most abundant and seemingly depth-sensitive Everglades wading bird, the White Ibis (Eudocimus albus). I implemented a 2-year experimental study in four replicated manmade wetlands with controlled water recession rates in order to determine the effects of proximate deep water (akin to canals) on fish prey concentrations in the sloughs, as water levels receded similarly to a natural Everglades dry season. I also calculated average daily wading bird densities with game cameras (Reconyx PC800 Hyperfire) using timelapse imagery over 60 days to determine when and where wading birds responded to changing prey concentrations. I completed an additional observational study on White Ibis and slough crayfish prey from the first year of data (2017). Crayfish make up the majority of the diet for nesting White Ibis, and literature has suggested crayfish are most abundant at slough depths much deeper than previously proposed foraging depth limitations for White Ibis. This study specifically compared recent determinations about crayfish movement dynamics in the ridge and slough system with White Ibis foraging behavior and depth limits. Results from the first experimental study suggest that canals might be an attractive refuge for relatively large prey fishes (> 3 cm SL) in sloughs, but it is uncertain if the fencing blocked all prey fish movement. The second observational study determined White Ibis foraging activity was primarily driven by a down-gradient crayfish flux from ridge to slough, with the majority of foraging activity occurring at much deeper slough depths than previously suggested water depth limitations for White Ibis. Results from both of these studies support the importance of preserving the ridgeslough landscape of the Everglades to sustain high prey availability for wading birds.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013124
- Subject Headings
- Wading birds, White ibis, Everglades (Fla)--Environmental conditions, Foraging behavior in animals, Predator & prey
- Format
- Document (PDF)
- Title
- INFLUENCE OF HYDROLOGICAL VARIATION ON WADING BIRD DIETS AND REPRODUCTION IN A LACUSTRINE WETLAND.
- Creator
- Essian, David A., Gawlik, Dale E., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Wetlandscape topography creates spatial variation in hydroperiod, which in turn creates spatial variation in biotic communities. Such spatiotemporal variation occurs on a large scale in some of the most productive wetlands in the world, including those of south Florida, U.S.A. Wading birds (Pelicaniformes and Ciconiiformes) are iconic, top-level consumers of such ecosystems. Infrequent drying is necessary to maintain the primary nest substrate (Salix caroliniana), and prey availability is...
Show moreWetlandscape topography creates spatial variation in hydroperiod, which in turn creates spatial variation in biotic communities. Such spatiotemporal variation occurs on a large scale in some of the most productive wetlands in the world, including those of south Florida, U.S.A. Wading birds (Pelicaniformes and Ciconiiformes) are iconic, top-level consumers of such ecosystems. Infrequent drying is necessary to maintain the primary nest substrate (Salix caroliniana), and prey availability is regulated by production of prey biomass in the wet season and the subsequent concentration of prey biomass into shallow pools during the dry season. The goal of this dissertation was to explicitly model wading bird nest abundance and survival as functions of water-level fluctuations, which were spatially nested (i.e., the effects of water-level fluctuations that occurred over a large scale were measured separately from the effects of water-level fluctuations that occurred over a small scale). In Chapter 2, I modeled colony-specific effects of wetlandscape water level fluctuations on wading bird nest abundance. Modeling the response at the colony level allowed the inclusion of important parameters that cannot be measured at the wetlandscape scale. For instance, each colony had its own optimal range of lake stage, which depended on local topography. I used the models to predict cumulative nest abundance under six hydrologic scenarios that were based on potential water management actions at Lake Okeechobee. I found that increasing water levels at the lake would marginally benefit the Great Egret but would substantially reduce long-term Snowy Egret and White Ibis populations. In Chapter 3, I modelled spatiotemporal distributions of fish biomass density in Lake Okeechobee’s littoral zone as a function of hierarchically nested hydrological variables. These models were consistent with the dynamic landscape connectivity model previously described in the literature. I modified the models to predict a binomial response which could then be linked to wading bird foraging threshold. The model predictions were used to estimate the number of available patch days during the breeding season, which was highly correlated with the number of nests for the great egret (Ardea alba), the snowy egret (Egretta thula), and the white ibis (Eudocimus albus). In Chapter 4, I used spatial statistics to better understand how interannual variability in resource wave patterns in the littoral zone influenced wading bird nest abundance. I found that more birds nested in years when the drying edge of the marsh moved further across the landscape. Great egret nest survival increased also, but small heron nest survival decreased. This decrease was likely because small herons continued to nest late into the season in years with longer waves, and, as with most bird species, nests that are initiated later in the season. In Chapter 5, I compiled conventional nestling diet data from 5 wading bird species sampled in 4 wetland types from 2010 to 2020 (not every wetland type was sampled in every year). This chapter provides a comprehensive, broad description of wading bird diets in south Florida, and quantifies interspecies, spatial, and interannual variation in nestling diets. By using a model-based approach to quantify the relative biomass of prey species and prey traits in nestling diets, I provide the first diet analysis that is fully reproducible across the large sympatric range of the wading bird species in the study (great egret, snowy egret, tricolored heron [Egretta tricolor], little blue heron [Egretta caerulea], and wood stork [Mycteria americana]).
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013908
- Subject Headings
- Wading birds, Wetland ecology, Okeechobee, Lake (Fla.), Lacustrine ecology, Lake ecology--Florida.
- Format
- Document (PDF)
