Understanding the link between indicator species and their environment is imperative to managing and conserving anthropogenically-altered ecosystems. Seasonally-pulsed wetlands are uniquely complex ecosystem where water-level fluctuations shape trophic interactions. Anthropogenic manipulation of water-level fluctuation threatens the integrity of these systems worldwide. Wading birds, a group of species sensitive to landuse changes and fluctuating habitat conditions, serve as important indicators for wetland health. I used wading birds in the Everglades, as a model system to address the challenges of environmental restoration within an ecosystem heavily impacted by anthropogenic activities. Specifically, I 1) identified the nesting response of Great Egret (Ardea alba), White Ibis (Eudocimus albus), and Wood Stork (Mycteria americana) to hydrologically-mediated changes in food availability and 2) quantified spatiotemporal foraging-habitat selection of Great Egrets, White Ibis, and Wood Storks to fluctuating hydrologic conditions. Collectively, model selection results suggest food availability, generated through dynamic hydrological conditions, is a strong predictor of the abundance of nesting birds in a given year. Great egret and white ibis produce the highest nests numbers in years when the frequency of days of rising water is low. Wood stork nest numbers are the highest in years with high prey production coupled with continuous prey availability. My study of resource selection indicated wading birds select foraging sites based on similar hydrologic parameters, but the response varies by species. Wood storks are more likely to forage in shallow cells (< 10 cm) drying with high recession rates (0.5-1.5 cm/day), and long time since last drydown (600 days). White ibises selected foraging cells with relatively shallow water depths (0-15 cm), intermediate recession rates (0.5-1.0 cm/day), and long time since drydown (600 days). Great egrets selected foraging cells with a wider range of water depths (0-20 cm) where recession rates were lower (0.5 cm/day). All species are more likely to forage in cells where water has not increased by more than 3 cm in the previous two weeks. These differences in resource selections correspond to morphological and behavioral differences in the species, whereby wood storks were more constrained hydrologically and would be more affected by water-level manipulation. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

Variation in the seasonal water level fluctuations of tropical and subtropical wetlands controls the production and concentration of aquatic fauna that support breeding wading birds. However, little is known about how particular components of the annual hydrologic cycle affect processes that control food availability and reproduction. This thesis identifies specific mechanisms responsible for transforming wet season prey standing stock into dry season prey concentrations, links landscape hydrological patterns to wading bird nesting, and presents a predictive model of Wood Stork nesting. I examined the supoort for several a priori hypotheses of factors affecting wading bird prey concentrations and wading bird nest effort. Factors affecting the concentration and vulnerability of prey were important for transferring secondary production to higher trophic levels. Receding water levels, microtopographic variation, and high standing stocks of prey were critical for generating pulses of food availabiltiy to meet the high energy requirements of breeding predatory birds. / by Bryan A. Botson. / Thesis (M.S.)--Florida Atlantic University, 2012 / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

A challenge to ensure the health of wading bird populations is to have a better understanding of the altered habitats that we must now consider part of their natural history. Throughout their range endangered Wood Storks (Mycteria americana) have been reported to forage in ditches, a disparate category of linear man-made waterways. In a 52-kmP 2 P study area on the east coast of central Florida, the characteristics of hydrologically diverse ditches were quantified, and their use by Wood Storks documented during their non-breeding season. Logistic regression analyses were carried out using the ditch characteristics as independent variables and Wood Stork presence/absence as the dependent variable. This study confirms the use of these marginal wetlands, and identifies the significance of emergent vegetation on the foraging habitat selection of Wood Storks in the dry season. / by Eleanor K. Van Os. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

Orientador: Edison Barbieri / Resumo: O complexo estuarino de Santos-Cubatão no litoral centro do estado de São Paulo, Brasil, local de extrema importância para a biodiversidade, encontra-se contraditoriamente pressionado pelas atividades antrópicas. O presente estudo teve como objetivo levantar, descrever e analisar quali-quantitativamente a assembleia de avifauna aquática que habita e se utiliza desta região, além de fornecer uma análise de seu status de conservação e indicar espécies com potencial bioindicador para a qualidade do ambiente. Para tal, foi feito um levantamento de dados secundários, provenientes dos âmbitos de Ciência-Cidadã, Licenciamento Ambiental e Pesquisa Científica. Em paralelo, foram coletados dados in situ a partir de dez campanhas mensais (novembro de 2018 a agosto de 2019), pelo método de censo visual por rota aquática na região estuarina dos municípios de Santos e Cubatão. Os dados secundários indicaram um total de 17 trabalhos realizados ao longo de um período de 20 anos, contribuindo com uma listagem de 135 espécies de avifauna aquática distribuídas em 33 famílias e 11 ordens. Apesar da maior contribuição das informações ser proveniente da Pesquisa Científica (117 espécies sendo 22 exclusivas), ressaltou-se a relevância dos dados oriundos da Ciência-Cidadã (108 espécies e 12 exclusivas), possibilitando informações relevantes para estudos relacionados à distribuição, conservação e movimentos migratórios. Ainda que em menor parcela (69 espécies e apenas uma exclusiva), os dados proveni... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Santos-Cubatão estuarine complex on the central coast of the state of São Paulo, Brazil, a site of extreme importance for biodiversity, is contradictorily under pressure from anthropic activities. This study aimed to reserch, describe and analyze qualitatively and quantitatively the water birds assembly that inhabits and uses this region, besides providing an analysis of its conservation status and indicating species with bioindicative potential for the quality of this environment. To this end, a secondary data analysis from the databases of Citizen Science, Environmental Compliance Services and Scientific Research was conducted. At the same time, in situ data were collected from ten monthly campaigns (November 2018 to August 2019) by the visual census method by water route in the estuarine region of the municipalities of Santos and Cubatão. From the secondary data survey, a total of 17 studies over a 20-year period were obtained, contributing to a list of 135 water birds species distributed in 33 families and 11 orders. Despite the major contributions of the information come from the Scientific Research (117 species and 22 exclusive), the relevance of the data from the Citizen Science (108 species and 12 exclusive) was highlighted, providing relevant information for studies related to distribution, conservation and migratory movements. Although in a minor proportion (69 species and only one exclusive), data from the Environmental Compliance Services provide information a... (Complete abstract click electronic access below) / Mestre

published_or_final_version / Biological Sciences / Master / Master of Philosophy

Conservation of intertidal habitats in the UK is vital in order to continue to support nationally and internationally important populations of non-breeding waterbirds. Historic reclamation for agriculture and industry has resulted in the loss and degradation of large areas of these intertidal habitats in estuaries and they continue to be threatened by sea-level rise. Managed realignment is one method which is increasingly being used to restore intertidal habitats. As managed realignment is a relatively new restoration technique, the extent to which knowledge of the biology of estuaries is applicable to managed realignment sites is unclear. Habitat restoration is often unsuccessful or incomplete, so a detailed knowledge of both the natural system and the characteristics of restored systems will usually be necessary to recreate fully-functional estuarine habitats. This thesis focuses on Nigg Bay Managed Realignment Site (Nigg Bay MRS), the first managed realignment site in Scotland, and follows the first four years of ecological development to gain an understanding of how breached realignment can be used to restore intertidal habitats to support non-breeding waterbirds. This thesis has six major aims: (i) to describe the development of saltmarsh, (ii) to describe the development of intertidal flat, (iii) to describe the colonisation by non-breeding waterbirds (iv) to determine how tidal cycle and weather affect patterns of waterbird use, (v) to determine which factors affect the spatial distribution of waders and finally (vi) to determine the patterns of use by individual birds. Four summers after the re-establishment of tidal conditions, almost all of the saltmarsh species recorded on the nearby saltmarsh had colonised Nigg Bay MRS, although recognisable communities had yet to establish. Three winters after the re- establishment of tidal conditions in Nigg Bay MRS, the sediments had a significantly smaller particle size and higher organic matter content compared to the fine sands of the adjacent intertidal flats. The intertidal invertebrate community also differed from the adjacent intertidal flats. Nigg Bay MRS attracted large numbers of non-breeding waterbirds and supported each of the most common wader and wildfowl species present in the wider estuary. Nigg Bay MRS performs a number of important functions for non-breeding waterbirds by: (i) providing a foraging and resting habitat when the tide is absent and intertidal sediments in Nigg Bay are exposed; (ii) providing a foraging resource as the tide passes over the intertidal sediments within the site once the intertidal flats in Nigg Bay are inundated; and (iii) providing a high tide roosting site. On days with low temperatures and high wind speeds, more waterbirds use Nigg Bay MRS, suggesting that it is likely to be providing sheltering benefits. Nigg Bay MRS also provides top-up feeding habitat. The factors that often influence the spatial distributions of waders in estuaries appear to be operating within Nigg Bay MRS. Wader densities are greater on the intertidal flats when they are accessible than on the saltmarsh. Wader densities are also greatest close to creeks and drainage channels, possibly due to higher invertebrate densities, more accessible prey or sheltering benefits. Colour-ringing and radio-tracking of Common Redshank established that Nigg Bay MRS has a subset of regular users, including both adults and juveniles, and the wader assemblage at night may differ from the assemblage during the day. These findings are discussed in terms of the implications for locating, designing and managing future managed realignment projects.

In south Florida, the Greater Everglades ecosystem supports sixteen species of wading birds. Wading birds serve as important indicator species because they are highly mobile, demonstrate flexible habitat selection, and respond quickly to changes in habitat quality. Models that establish habitat relationships from distribution patterns of wading birds can be used to predict changes in habitat quality that may result from restoration and climate change. I developed spatio-temporal species distribution models for the Great Egret, White Ibis, and Wood Stork over a decadal gradient of environmental conditions to identify factors that link habitat availability to habitat use (i.e., habitat selection), habitat use to species abundance, and species abundance (over multiple scales) to nesting effort and success. Hydrological variables (depth, recession rate, days since drydown, reversal, and hydroperiod) over multiple temporal scales and with existing links to wading bird responses were used as proxies for landscape processes that influence prey availability (i.e., resources). In temporal foraging conditions (TFC) models, species demonstrated conditional preferences for resources based on resource levels at differing temporal scales. Wading bird abundance was highest when prey production from optimal periods of wetland inundation was concentrated in shallow depths. Similar responses were observed in spatial foraging conditions (SFC) models predicting spatial occurrence over time, accounting for spatial autocorrelation. The TFC index represents conditions within suitable depths that change daily and reflects patch quality, whereas the SFC index spatially represents suitability of all cells and reflects daily landscape patch abundance. I linked these indices to responses at the nest initiation and nest provisioning breeding phases from 1993-2013. The timing of increases and overall magnitude of resource pulses predicted by the TFC in March and April were strongly linked to breeding responses by all species. Great Egret nesting effort and success were higher with increases in conspecific attraction (i.e., clustering). Wood Stork nesting effort was closely related to timing of concurrently high levels of patch quality (regional scale) and abundance (400-m scale), indicating the importance of a multi-scaled approach. The models helped identify positive and negative changes to multi-annual resource pulses from hydrological restoration and climate change scenarios, respectively. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Anthropogenic hydrologic alterations can affect the quality of lake littoral zone habitats for wading birds, such as the great egret (Ardea alba), snowy egret (Egretta thula), and white ibis (Eudocimus albus). One such lake in Florida, Lake Okeechobee, has experienced a marked decline in wading bird nesting since the 1970’s, concomitant with changes in lake level management. It’s hypothesized that a reduction in foraging habitat has led to the nesting decline; however, there is little quantitative evidence of this link. A habitat suitability model was developed for Lake Okeechobee wading birds that incorporate the spatial and temporal dynamics of environmental factors that affect wading bird foraging and tests whether foraging habitat is linked to numbers of nests. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

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