Roseate spoonbill reproduction as an indicator for restoration of the Everglades and the Everglades estuaries

Abstract

Ecological monitoring is a key part of adaptive management and successful restoration. Not everything within an ecosystem can be monitored so it is important to select indicators that are representative of the system, integrate system responses, show clear responses to system change, can be effectively and efficiently monitored, and are easily communicated. Roseate Spoonbills are one of the indicators that meet these criteria within the Everglades ecosystem. Monitoring of Roseate Spoonbills in Florida Bay over the past 70 years has shown that this species responds to changes in hydrology and corresponding changes in prey abundance and availability. This indicator uses nesting location, nest numbers and nesting success in response to food abundance and availability. In turn, prey abundance is a function of hydrological conditions including depth, and salinity. These relationships have been well documented such that spoonbills responses can be directly related to changes in hydrology and salinity.The spoonbill indicator uses performance measures that have been shown to be both effective and efficient in tracking trends. They are: nesting success, nest number, locations of nests, and prey fish community composition. Targets for these performance measures we established based on previous findings. The performance measures are then reported as suitability indices identified as stoplight colors with green indicating that targets have been met, yellow indicating that conditions are below the target but within a suitable range of it and red indicating the measure is performing poorly in relation to the target.

The contrasting feeding ecology of great egrets and roseate spoonbills in limnetic and estuarine colonies

“…In the Florida Bay, spoonbills breeding on estuarine islands also move to inland foraging areas (Lorenz et al, 2009). The egrets seemed to forage closer to the colony because the estuary is \300 m from the colony, as indicated by SIA.…”

“…In the freshwater colony, the presence of rice grains in the spoonbills' diet indicates that they were foraging in irrigated rice fields, which are approximately 10 km from the colony; this is well inside the [30 km foraging radius of breeding roseate spoonbills feeding chicks in Florida (Lorenz et al, 2009).…”

“…Spoonbills have been reported to forage from hypersaline ponds and marine areas to freshwater lakes (Dumas, 2000). Spoonbills prefer freshwater in some areas, such as in Florida (USA) (Lorenz et al, 2009), which may be related to a limited ability to deal with hyperosmotic prey, as demonstrated for white ibis Eudocimus albus (Linnaeus, 1758) (Johnston & Bildstein, 1990). The Eurasian spoonbill Platalea leucorodia Linnaeus, 1758 relies entirely on marine resources during breeding in Mauritania (El-Hacen et al, 2013), but may switch from limnetic to marine prey during the breeding period in The Netherlands (El-Hacen et al, 2014).…”

Climate Change Projected Effects on Coastal Foundation Communities of the Greater Everglades Using a 2060 Scenario: Need for a New Management Paradigm

“…1) provide nutrition and create critical benthic habitats that for a diversity of wildlife (e.g., fish, shellfish, wading birds, and other waterfowl; Davis and Dodrill 1989;Thayer and Chester 1989;Tilman 1989;Ley et al 1999;Lorenz et al 2009). Seagrasses, freshwater submerged aquatic plants and marine macroalgae comprise this broad vegetative community.…”

Science behind management of Shark Bay and Florida Bay, two P-limited subtropical systems with different climatology and human pressures

“…For example, Thalassia testudinum has replaced Halodule wrightii as the dominant seagrass species in much of north and north-eastern Florida Bay due to increased salinities favouring the former species (Zieman et al 1989;Fourqurean et al 2003). Impacts of salinity changes have also occurred for higher-trophic-level species, such as wading birds (Lorenz et al 2009). …”