Environmental and anthropogenic factors structuring waterbird habitats of tropical coastal lagoons: Implications for management

Tavares, Davi Castro; Guadagnin, Demétrio Luís; Moura, Jailson Fulgêncio de; Siciliano, Salvatore; Merico, Agostino

doi:10.1016/j.biocon.2015.02.027

Cited by 78 publications

(73 citation statements)

References 95 publications

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“…We assessed the appropriate level of each significant variable (obtained from GLMMs) graphically by consolidating smoothing capacities into the generalized additive mixed models (GAMMs) following Tavares et al (2015). Different values of knots (k) were tested to make effective degrees of freedom (edf) not much less than kÀ1 for each model following the guidelines of Wood (2006).…”

Section: Statistical Analysesmentioning

confidence: 99%

“…Several studies have demonstrated that environmental variables such as wetland hydrology and landscape can alter waterbird abundance in different ways (Alexander & Hepp, 2014;Brandolin & Blendinger, 2016;Tavares, Guadagnin, de Moura, Siciliano, & Merico, 2015;Wen, Rogers, Saintilan, & Ling, 2011). For example, fluctuations in water depth influence the physical condition of waterbird habitats (e.g., the establishment of mudflats), affect food availability, and prey vulnerability (Bellio & Kingsford, 2013;Lantz, Gawlik, & Cook, 2011;Timmermans, Badzinski, & Ingram, 2008;Y.…”

Section: Introductionmentioning

confidence: 99%

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Changing Landscapes and Declining Populations of Resident Waterbirds: A 12-Year Study in Bung Boraphet Wetland, Thailand

Haq

Eiamampai²,

Ngoprasert

et al. 2018

Tropical Conservation Science

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Changes in wetland environments can alter the dynamics of waterbird populations. We investigated the effects of hydrological and landscape variables on the abundance of resident waterbirds (ducks, fish-eaters, large waders, small waders, and vegetation gleaners) from 2003 to 2014 in Bung Boraphet, Thailand's largest freshwater wetland. Generalized linear mixed models were used to determine the effects of environmental variables on waterbird numbers, and generalized additive mixed models were used to identify the threshold for each effect. The results revealed that the population of all waterbirds declined by 27% from 2003 to 2014 with highest decline of 56% in ducks. Increasing water depth was negatively correlated with the abundance of small waders and vegetation gleaners. Higher concentrations of dissolved oxygen in the water increased the abundance of fish-eaters, while marshy areas were positively associated with the abundance of ducks, large waders, and vegetation gleaners. The abundance of fish-eaters, large waders, and small waders were negatively associated with the spatial area of waterbodies. Expanding human settlements decreased the abundance of vegetation gleaners, while vegetation infested by Mimosa pigra decreased the abundance of large waders. The study concludes that the maintenance of an optimal water depth and quality, preservation of critical marsh habitats, eradication of invasive species, and restrictions on new human settlements adjacent to wetlands are all necessary to conserve resident waterbird populations. Validating these findings in additional research sites is recommended before applying it to a broader landscape level.

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Section: Statistical Analysesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Changing Landscapes and Declining Populations of Resident Waterbirds: A 12-Year Study in Bung Boraphet Wetland, Thailand

Haq

Eiamampai²,

Ngoprasert

et al. 2018

Tropical Conservation Science

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“…However, to monitor at-sea densities is expensive and logistically challenging, making this unsuitable for developing countries such as Brazil. However, the seabirds species examined herein are more abundant and forage within 20 km from breeding sites, where they aggregate to reproduce and forage throughout the year [3, 5, 46, 56, 65, 66]. Thus, we used the linear distance between the nearest breeding island and the centre of surveyed transects as a metric for seabird at-sea abundance, i.e., the level of exposure of these organisms to local potential causes of death (i.e.…”

Section: Methodsmentioning

confidence: 99%

“…This technique allowed for the identification of non-normal response variables and spatial dependence of observations [69]. We fitted models to predict stranding events for each of the seabird species studied, with predictor variables set as fixed effects and sampling areas included as random effects, thus accounting for spatial correlations [3]. Since T .…”

Section: Methodsmentioning

confidence: 99%

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Environmental Predictors of Seabird Wrecks in a Tropical Coastal Area

2016

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Beached bird surveys have been widely used to monitor the impact of oil pollution in the oceans. However, separating the combined effects of oil pollution, environmental variables and methodological aspects of beach monitoring on seabird stranding patterns is a challenging task. The effects of a comprehensive set of oceanographic and climatic variables and oil pollution on seabird strandings in a tropical area of Brazil were investigated herein, using two robust and innovative methods: Generalized Linear Mixed Models and Structural Equation Modeling. We assessed strandings of four resident seabird species along 480 km of beaches divided into 11 sampling areas, between November 2010 and September 2013. We found that increasing the distance from the nearest breeding island reduce the seabird stranding events. Storm activity and biological productivity were the most important factors affecting the stranding events of brown boobies Sula leucogaster, Cabot’s terns Thalasseus acuflavidus and kelp gulls Larus dominicanus. These species are also indirectly affected by warm tropical waters, which reduce chlorophyll-a concentrations. Beach surveys are, thus, useful to investigate the mortality rates of resident species near breeding sites, where individuals are more abundant and exposed to local factors associated with at-sea mortality. In contrast, conservation actions and monitoring programs for far-ranging seabird species are needed in more distant foraging areas. Furthermore, beach monitoring programs investigating the impact of oil pollution on seabirds need to account for the effects of environmental factors on stranding patterns. The present study also demonstrated that seabirds inhabiting tropical coastal waters are sensitive to climate conditions such as adverse weather, which are expected to increase in frequency and intensity in next decades.

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Seasonal differences in drivers of species richness of waders in inland wetlands of La Mancha Húmeda Biosphere Reserve

Gonçalves

Gil‐Delgado

Gosálvez

et al. 2018

Aquatic Conservation

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Temporary inland wetlands are among the most threatened ecosystems worldwide, and recognition of the factors that determine species richness in different seasons is key for developing conservation plans for these systems. La Mancha Húmeda Biosphere Reserve in central Spain has many inland wetlands of this type, but the driving ecological processes of species richness are poorly understood. This study examines the association of landscape and local variables with species richness patterns of inland wetlands of La Mancha Húmeda Biosphere Reserve during winter and the breeding season. The number of lakes in several increasing radii was a proxy of connectivity, and maximum flooded surface and shoreline length were surrogates of the species–area relationship. Other landscape and local habitat variables, such as hydroperiod (length of inundation period), distance from human settlements, shoreline development index, vegetation surface cover, average lake depth, number of islands and surface area of islands were also analysed. Hierarchical partitioning analysis was used to evaluate the contribution of the environmental variables to explain the species richness of waders. Species richness (26 species, four threatened in Europe) had different associations with the variables during the wintering and breeding seasons. The richness of breeding and wintering species was positively associated with hydroperiod and maximum flooded surface area respectively. No variable measured was negatively associated with species richness in any season. Hydroperiod and flooded surface area are altered directly by human activities. Water extraction for irrigation reduces hydroperiod in some wetlands, whereas wastewater input extends hydroperiod in others, promoting wader concentrations in lakes flooded in summer and potentially favouring botulism outbreaks. In addition, the lack of protection and management on most of the lakes in La Mancha Húmeda Biosphere Reserve also favours encroachment of agriculture, destroying and degrading habitat for wintering and breeding waders.

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Environmental and anthropogenic factors structuring waterbird habitats of tropical coastal lagoons: Implications for management

Cited by 78 publications

References 95 publications

Changing Landscapes and Declining Populations of Resident Waterbirds: A 12-Year Study in Bung Boraphet Wetland, Thailand

Changing Landscapes and Declining Populations of Resident Waterbirds: A 12-Year Study in Bung Boraphet Wetland, Thailand

Environmental Predictors of Seabird Wrecks in a Tropical Coastal Area

Seasonal differences in drivers of species richness of waders in inland wetlands of La Mancha Húmeda Biosphere Reserve

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