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Item Anthropogenic food in the diet of the Sacred Ibis, Threskiornis aethiopicus, a non-native wading bird in southeastern Florida, USA(Florida Field Naturalist, 2011-03) Calle, Leonardo; Gawlik, Dale E.The Sacred Ibis ( Threskiornis aethiopicus ), is native to sub-Saharan Africa. A small breeding population in southeastern Florida, USA, was established in 1992 and expanded to surrounding natural areas until 2008 when an eradication program was initiated. This study investigated the degree to which the population of Sacred Ibis in South Florida consumes food items derived from human activities which may have contributed to its population expansion. Body measurements, the first such data for this species in North America, were obtained for eight adult males and five adult females. The contents of the esophageal tract and gizzards were used to classify ibis diets (N = 22) as being of anthropogenic origin (derived from human activities) if they contained cheese, meat, paper pulp, and/or pellet meal. The diet of the Sacred Ibis was comprised of predominately anthropogenic food items (58% of the cumulative biomass). Ibises with anthropogenic food items found in their diet consumed more biomass (26.99g ± SE 5.35g) than did birds that contained only natural food items in their diet (8.74g ± SE 2.21g). Natural diets, on average, contained a significantly greater percent vegetative matter (63% ± SE 12%) than did anthropogenic diets (8% ± SE 3%). Novel organic and inorganic items found in anthropogenic diets included bacon, glass, hot dog, pellet meal, and plastic. A cluster analysis revealed that some ibises used anthropogenic food as a primary food source whereas others used it as a supplement to natural food items. This study suggests that human food resources, and the habitats that contain them, may have the ability to support this species’ establishment. Further investigation, of ecologically similar species, may elucidate linkages between human food resources in urbanized areas and impacts in nearby natural habitats.Item Aquatic prey switching and urban foraging by the White Ibis Eudocimus albus are determined by wetland hydrological conditions(The Authors and The British Ornothologists' Union, 2011-02-22) Dorn, Nathan J.; Cook, Mark I.; Herring, Garth; Boyle, Robin A.; Nelson, Jennifer; Gawlik, Dale E.Prey availability is known to limit reproduction of some species of nesting birds, but identifying the primary prey types of a species with a flexible diet can be challenging. For the White Ibis Eudocimus albus, a tactile feeding, medium-sized wading bird, nestling prey composition is suggested to depend on landscape water depths⁄ availability of foraging habitat at the time of nesting and on historical drying events affecting prey production. We collected and compared inter- and intra-annual diet variation of White Ibis chicks reared in the Everglades over two years that were independently identified as being relatively good (2006) and poor (2007) nesting seasons. We collected 127 nestling boluses and analyzed the temporal variation in biomass of eight functional prey groups using multivariate techniques. The boluses from 2006 in the central Everglades were dominated by fish, but in 2007, after fish had been reduced by the previous year of drying, the boluses from the same region were more variable and dominated by garbage (i.e.scavenging). Analysis of five different collections taken from a different colony in the northern Everglades indicated that boluses were characterized by crayfish and had fewer fish or less garbage when landscape water depths were relatively higher and more preferred habitat was available. At lower landscape water depths in 2007 the bolus composition shifted away from crayfish towards small fish and urban food (terrestrial insects and garbage). Our results support the suggestion of depth-dependent diets; prey composition depends on the current landscape water levels around the colonies, and also suggests that previous drying events can lead to increased reliance on alternative food sources. White Ibis partially compensated for unavailable aquatic prey with alternative urban foods, but their nesting success appears to have sufferedItem Assessing drought-related ecological risk in the Florida Everglades(Elsevier, 2003-04-28) Smith, Stephen M.; Gawlik, Dale E.; Rutchey, Ken; Crozier, Gaea E.; Gray, SusanIn the winter-spring of 2001, South Florida experienced one of the worst droughts in its recorded history. Out of a myriad of ecological concerns identified during this time, the potential for catastrophic peat fire and negative impacts to wading bird reproduction emerged as critical issues. Water managers attempted to strike a balance between the environment and protection of water supplies for agriculture and urban interests. It became evident, however, that a broad-scale, integrated way to portray and prioritise ecological stress was lacking in the Florida Everglades, despite this being considered a necessary tool for addressing issues of environmental protection. In order to provide a framework for evaluating various water management operations using real-time information, we developed GIS-based indices of peat-fire risk and wading bird habitat suitability. These indices, based on real physical, chemical, and biological data, describe two ecological conditions that help define the physical and biological integrity of the Everglades. In addition to providing continuous, updated assessments throughout the drought period, we incorporated predictive models of water levels to evaluate how various water management alternatives might exacerbate or alleviate ecological stress during this time.Item Assessing drought-related ecological risk in the Florida Everglades(Elsevier, 2003-04-28) Pierce, Rachael L.; Gawlik, Dale E.To determine how habitat structural complexity, which affects prey vulnerability, influences foraging habitat selection by wading birds, a habitat use versus availability study was conducted throughout the Florida Eve glades in 2005 and 2006. Also, an experiment was conducted where structural complexity was manipulated and effect on wading bird foraging efficiency quantified. Among-year differences in habitat selection were found, which corresponded to disparate hydrological conditions. In 2005, a poor hydrological year in terms of the seasonal r cession, wading birds chose foraging sites that had less emergent vegetation, a thicker flocculent layer and higher prey density relative to random sites. In 2006, an optimal hydrological year, wading bird foraging locations we similar to random sites in all aspects. Submerged vegetation did not affect wading bird site selection in either yea The study indicated that hydrological conditions that affect prey density were more important to wading bird foraging success than fine scale variation in habitat characteristics. However, in years of poor hydrology factors that affect prey vulnerability may become increasingly important because the penalty for choosing low quality foraging habitat is greater than in years of more optimal conditions. Elucidating habitat characteristics which create high quality foraging sites will be beneficial in planning wetland restoration projects and gauging future restoration progress. Received 2 October 2009, accepted 18 May 2010.Item Avian Communities in Bayheads, Willowheads, and Sawgrass Marshes of the Central Everglades(Wilson Bulletin, 1997-10-03) Rocque, Deborah A.; Gawlik, Dale E.We compared avian community composition, species richness, and total bird abundance among three vegetation types (bayheads, willowheads and marshes), and between a reduced-hydroperiod and relatively unimpacted landscape in the central Everglades during July-August, 1996. Our results showed that the collective Everglades bird community contained a substantial number of forest birds as well as marsh species. Red-winged Blackbirds (Agelaius phoeniceus), Common Yellowthroats (Geothlypis trichas), and White-eyed Vireos (Vireo griseus) accounted for 65% of total individual birds during the period of study. Wading birds accounted for a relatively small proportion of the total avian community. White-eyed Vireo was the most abundant bird species in bayheads and was closely associated with that habitat. Red-winged Blackbird and Common Yellowthroat were the most abundant species in both willowheads and marsh vegetation. We found no significant difference in bird abundance among vegetation types (P > 0.05) nor between landscapes (P > 0.05). We also found no difference in species richness between landscapes (P > 0.05). A significant (P = 0.02) interaction between vegetation and landscape indicated that species richness differed among vegetation types in the unimpacted landscape, but not in the reduced-hydroperiod landscape. In the unimpacted landscape we detected significantly more species in bayheads than the other two vegetation types (both tests, P ' 0.004). An ordination revealed that in the unimpacted landscape, bird communities were more specific to vegetation types than in the reduced- hydroperiod landscape. Our study demonstrates that two characteristics of a relatively unimpacted landscape in the central Everglades are higher avian species richness and a more distinct avian community in bayheads than in willowheads or marshes. The Everglades restoration process will promote the conservation of avian diversity by restoring the landscape matrix of both marsh and bayhead vegetation.Item Avian Radio-transmitter Harness Wear and Failure(Eagle Hill Institute, 2010) Herring, Garth; Gawlik, Dale E.Although investigators have compared radio-transmitter attachment devices and their likelihood of failure before the end of a study, few have directly evaluated the harness materials and fastening methods that are to be shed by a bird after the research period is over. We compared the likelihood of effective detachment after transmitter life of four harness materials (7-mm- and 9-mm-wide polyester rib- bon tape and polyester-coated rubber elastic) and three fastening methods (polyester thread, cotton thread, and Gorilla Super Glue™) using dummy transmitters exposed to the elements for >1.5 years. Both polyester ribbon and polyester-coated rubber elastic materials resulted in similar physical wear and remained intact for longer than a typical field seasonal, but fastening harnesses using Gorilla Super Glue™ resulted in the earliest and most consistent harness failure. Polyester ribbon material and glue fastening resulted in the earliest failure; mean failure time for 7-mm- and 9-mm-wide polyester ribbon tape with glue fastening was 408 days ±30 SE, and 249 days ± 29 SE, respectively. Failure times for both 7-mm- and 9-mm-wide polyester- coated rubber elastic and Gorilla Super Glue™ fastening treatments were in excess of one year (438 days ± 14 SE and 438 days ± 13 SE, respectively). All harnesses with sewn thread fastening treatments lasted a minimum mean of 456 days, and i the case of both 7-mm-wide polyester ribbon and polyester-coated rubber elastic neither treatment ever failed over the period of study. Results suggest that using Gorilla Super Glue™ as a fastener maximized the likelihood of eventual harness failure, whereas transmitters fastened via sewing showed minimal signs of wear an were unlikely to be shed by a bird during a period of time less than two years. Additional experimental studies are warranted to examine alternative harness material types, fastening methods, and harness styles to maximize the potential of successful radio transmitter shedding.Item Avian response to nutrient loading in an oligotrophic wetland(The Condor, 2002-08-01) Gawlik, Dale E.; Crozier, Gaea E.We studied the effects of nutrient enrichment on the bird community in an oligotrophic wetland, the Florida Everglades. Among the non-wading birds surveyed in 1996 and 1997, Boat-tailed Grackles (Quiscalus major) and Common Moorhens (Gallinula chloropus) were consistently more abundant in enriched sites, whereas Common Yellowthroats (Geothlypis trichas) were consistently more abundant in unenriched sites. The abundance of Red-winged Blackbird (Agelaius phoeniceus) was not significantly different between enriched and unenriched sites. Among wading birds, Wood Storks (Mycteria americana) and Great Egrets (Ardea alba) were significantly more abundant in enriched than unenriched areas in a dry year, 1991. Great Egrets and all wading species combined were significantly more abundant in enriched than unenriched areas in the wet year, 1995. Great Blue Herons (Ardea herodias) and White Ibises (Eudocimus albus) did not differ in abundance between enriched and unenriched areas in the dry or wet year. A significant interaction between water depth and nutrient status in the wet year indicated that wading bird abundance increased with water depth only in nutrient-enriched areas presumably because the enriched areas had greater food availability than unenriched areas at the same water depth. Bird abundance appeared to increase in nutrient-enriched areas; however, this increase was accompanied by a shift in species composition typically found in the unenriched Everglades and was a fundamental change in the Everglades' distinctive structure.Item The avifauna of constructed treatment wetlands in South Florida used for Everglades restoration(Florida Field Naturalist, 2007) Chimney, Michael J.; Gawlik, Dale E.Constructed treatment wetlands invariably create wildlife habitat (Kadlec and Knight 1996, U.S. Environmental Protection Agency 1999, Knight et al. 2001). Habitat improvement can be dramatic, especially when these systems are built on degraded areas such as farm fields (Hickman 1994). The South Florida Water Management District (SFWMD) and the U.S. Army Corps of Engineers have built a complex of large treatment wetlands, known as Stormwater Treatment Areas (STAs), on reclaimed farmland in south Florida as part of a multi-billion dollar effort by State and Federal governments to protect and restore the Everglades (Chimney and Goforth 2001, Sklar et al. 2005, SFWMD 2006). Current plans call for the STAs to encompass more than 17,000 ha. These wetlands were designed to treat and reduce high phosphorus concentrations in stormwater runoff from the Everglades Agricultural Area (EAA) before this water enters the northern portion of the remaining Everglades, the Water Conservation Areas (WCAs) (Fig. 1). The STAs have attracted a high abundance and diversity of wildlife species, including many birds. This paper presents a checklist of the avifauna found in two of the STAs and compares STA bird community composition and species richness with regional and other treatment wetlands.Item Call rate as an index of nest count in wading bird colonies(International Journal of Avian Science, 2022-12-03) Larson, Rachel; Gawlik, DaleTraditional monitoring methods for colonial waterbirds, such as nest counts, can be expensive, time-intensive, disruptive to nesting birds and limited by colony accessibility. Our study tested the use of acoustic sampling as a colony monitoring technique for three species of colonially nesting herons (Ardeidae) by quantifying the relationship between chick call rate and nest count in colonies. Because acoustic detection can be influenced by soundscape variables, we measured day since colony initiation, body condition index of small heron chicks, nest height, vegetation density and wind speed and evaluated their effects on call rate detection. Generalized linear mixed-effects models showed that call rate detection increased with daily nest count for all species. Snowy Egret Egretta thula and Tricoloured Heron Egretta tricolour detected call rate was also dependent on environmental, temporal and physiological variables, whereas Great Egret Ardea alba call detection was affected by vegetation density around nests and wind speed. Our study showed that wading bird nest counts can be estimated using acoustic sampling, reducing the need for manual colony surveys, and facilitating long-term monitoring of wading bird nesting trends, which are important measures of wetland restoration worldwide.Item Community Patterns In Treatment Wetlands, Natural Wetlands, and Croplands In Florida(The Wilson Journal of Ornithology, 2013-06-01) Beck, Tyler J.; Gawlik, Dale E.; Pearlstine, Elise V.In Florida, roughly 18,000 ha of treatment wetlands called Stormwater Treatment Areas (STAs) have been constructed on agricultural land to reduce phosphorous loads to the Everglades. Little is known about how avian communities in these STAs compare to those present on other similar land types. In 2008–2009, point counts were conducted seasonally in the STAs, nearby croplands, and natural Everglades marsh to compare avian communities among these habitats. Overall, avian densities were nearly three times greater in STAs than in the croplands and 38 times greater than in the natural marsh. Local species richness in the STAs was 78% greater than in croplands and nearly four times greater than in the natural marsh. Although natural marshes may have more structural complexity than the croplands and STAs, their oligotrophic status probably limits their ability to support a large bird community. Avian densities varied seasonally among habitat types; avian density was greatest in the winter in STAs as a result of high densities of migratory waterfowl. The STAs may be providing wintering habitat to a significant portion of the North American waterfowl population, including as much as 8% of the breeding population of American Coots (Fulica americana). If the trend of increasing numbers of treatment wetlands continues, it has the potential to alter the distribution of wetland birds, a group that has previously suffered population declines because of habitat loss.Item Comparative foraging behavior of sympatric Snow Geese, Greater White-fronted Geese, and Canada Geese during the non-breeding season(Wilson Bulletin, 1996-03-01) Gawlik, Dale E.; Slack, R. D.Interspecific comparisons of behavior provide a way to organize information for several species that can lead to hypotheses regarding the functional significance of observed interspecific differences (Clutton-Brock and Harvey 1984). Previous studies of goose time-activity budgets (e.g., Frederick and Klaas 1982, Giroux and Bedard 1990, Black et al. 1991, Ely 1992) have focused on single species and collectively were conducted under widely differing environmental conditions. Certain environmental factors are known to affect goose behavioral patterns and may confound direct interpretation of interspecific comparisons (Table 1). These environmental factors include geographic region, weather, presence of heterospecifics, group size, habitat and vegetation type, year, season, age, social status, and gender. We are aware of no studies that have controlled for environmental variation and examined differences in timebudgets solely as a function of species membership. The objective of this study was to identify interspecies differences (and similarities) in foraging behavior of geese during the non-breeding season, while accounting for sources of environmental variation.Item Conservation Biology and the Evolution of a Land Ethic(Journal of Raptor Research, 1992) Gawlik, Dale E."Conservation biology" is reportedly distinct from other natural sciences because of its focus on a wide array of biota, the long-term scale at which it operates, its holistic nature, its assumption that organisms have an intrinsic value and its direct application of research to a management goal. However, most of what contemporary conservation biologists endorse was previously proposed by Aldo Leopold, and practiced by two of his former students, Frederick and Frances Hamerstrom. That their work with Northern Harriers (Circus cyaneus hudsonius) and Greater Prairie Chickens (Tympanuchus cupidopinnatus) has received widespread recognition is a testimony to the effectiveness of this approach. Conservation biology is only now gaining widespread acceptance probably because of the increasing importance that society has recently placed on the environment. Leopold predicted that society's perception of the environment would move towards what he termed a "land ethic" before the approach endorsed by contemporary conservation biologists could be successful. We may be witnessing the stirring of just such a movement.Item Determining habitat quality for species that demonstrate dynamic habitat selection(Ecology and Evolution, 2015-11-19) Beerens, James M.; Frederick, Peter C.; Noonburg, Erik G.; Gawlik, Dale E.Determining habitat quality for wildlife populations requires relating a species' habitat to its survival and reproduction. Within a season, species occurrence and density can be disconnected from measures of habitat quality when resources are highly seasonal, unpredictable over time, and patchy. Here we establish an explicit link among dynamic selection of changing resources, spatio‐temporal species distributions, and fitness for predictive abundance and occurrence models that are used for short‐term water management and long‐term restoration planning. We used the wading bird distribution and evaluation models (WADEM) that estimate (1) daily changes in selection across resource gradients, (2) landscape abundance of flocks and individuals, (3) conspecific foraging aggregation, and (4) resource unit occurrence (at fixed 400 m cells) to quantify habitat quality and its consequences on reproduction for wetland indicator species. We linked maximum annual numbers of nests detected across the study area and nesting success of Great Egrets (Ardea alba), White Ibises (Eudocimus albus), and Wood Storks (Mycteria americana) over a 20‐year period to estimated daily dynamics of food resources produced by WADEM over a 7490 km2 area. For all species, increases in predicted species abundance in March and high abundance in April were strongly linked to breeding responses. Great Egret nesting effort and success were higher when birds also showed greater conspecific foraging aggregation. Synthesis and applications: This study provides the first empirical evidence that dynamic habitat selection processes and distributions of wading birds over environmental gradients are linked with reproductive measures over periods of decades. Further, predictor variables at a variety of temporal (daily‐multiannual) resolutions and spatial (400 m to regional) scales effectively explained variation in ecological processes that change habitat quality. The process used here allows managers to develop short‐ and long‐term conservation strategies that (1) consider flexible behavioral patterns and (2) are robust to environmental variation over time.Item Developing a Fine-Resolution Digital Elevation Model to Support Hydrological Modeling and Ecological Studies in the Northern Everglades(Bellwether Publishing, 2013-05-15) Xie, Zhixiao; Pearlstine, Leonard; Gawlik, Dale E.Accurate high-resolution terrain data are essential for hydrological modeling in lowlands. This study integrates elevation survey data and vegetation data at the point and 50 m scales to develop a fine-resolution digital elevation model (DEM) for the northern Everglades of Florida. The terrain was divided into two vertical strata (lowland and highland) based on a 50 m scale vegetation map. The DEM in high-lands was interpolated with all the survey points and later adjusted using an association between vegetation and hydroperiod (the number of days per year that land is flooded). The DEM in lowlands was interpolated with elevation surveys tagged as lowland types. The two DEMs were then combined, forming a new DEM with a 7.7 cm mean absolute validation error— a significant (2.3 cm) improvement over the previous DEM.Item Dietary flexibility of Wood Storks in response to human-induced rapid environmental change(Springer Science+Business Media, 2021-11-04) Evans, Betsy A.; Klassen, Jessica A.; Gawlik, Dale E.Human-induced rapid environmental change (HIREC) has altered landscape processes and negatively impacted many species globally. Some of the most dramatic changes have been in wetlands where flows have been disrupted, and new wetlands have been created to retain runoff. In response to disrupted natural wetland conditions, Wood Stork (Mycteria americana) populations in South Florida have significantly declined over the past several decades. Despite the well-documented sensitivity of Wood Storks to natural wetland conditions, Wood Storks are often observed foraging in roadside created wetlands; however, the availability of prey in created wetlands is currently unknown. We sampled natural and created wetlands to determine aquatic fauna available for foraging Wood Storks. To determine prey use, we collected food boluses from Wood Storks in both natural wetland and urban landscapes. Historical studies found nonnative fsh were absent in Wood Stork diet prior to the dominance of created wetlands in the landscape; however, we found nonnative fsh frequently in both created wetlands and boluses. Furthermore, urban nesting Wood Storks consumed large-bodied prey species that were more characteristic of created wetlands whereas Wood Storks nesting in natural wetlands consumed large-bodied prey more characteristic of natural wetlands. Overall, Wood Storks consumed prey that were more similar to the fish community in created wetlands than those in natural wetlands. These dietary patterns suggest that Wood Storks have behavioral plasticity in both foraging habitat and prey use to cope with HIREC. Conservation efforts for species existing in both natural and urban habitats should consider the importance of novel prey and foraging habitats, as they may assist in sustaining populations in a rapidly changing world.Item Differential physiological responses to prey availability by the great egret and white Ibis(The Wildlife Society, 2012-08-13) Herring, Garth; Gawlik, Dale E.In long-lived species, the balance between the benefits of reproduction and the costs from reduced survival or productivity is particularly challenging in dynamic environments like wetlands, where food levels vary greatly year to year. Some wetland species exhibit changes in reproductive strategies in response to food availability but whether physiological responses function in a similar manner is unclear. We compared the pre-breeding physiological responses (fecal corticosterone [FCORT], heat shock protein 60 [HSP60], and mass) of 2 species of wading birds with contrasting foraging strategies (great egret [Ardea alba], an exploiter, and white ibis [Eudocimus albus], a searcher) during years with contrasting levels of prey availability. Both species were in good physiological condition, with low levels of HSP60 and FCORT, during a year with high prey availability (2006). In a contrasting year with lesser prey availability (2007), HSP60 and FCORT concentrations indicated that ibis physiological condition was reduced, whereas egrets showed little change. Egrets and male ibis increased body mass, whereas female ibis decreased mass, in the year with low prey availability. Although poorly understood, we hypothesize that the differential response between female ibis and the others is associated with differential investment strategies based on long-term costs of reproduction. Model results identified prey availability and the 2-week water recession rate as the primary habitat variables that were associated with the physiological condition of white ibises, whereas great egret physiological condition was influenced mostly by 2-week water recession rate. Our results support the hypothesis that prey availability and hydrological factors play crucial roles in regulating populations of wading birds in the Florida Everglades. The results of this study show a more complete pathway by which hydrologic patterns affect wading birds, and it suggests that ibis are more sensitive to habitat conditions than are egrets. This information can be used to refine species models designed to evaluate water management scenarios and will improve our ability to manage and restore wetland ecosystems © 2012 The Wildlife Society.Item Distribution of Wading Birds Relative to Vegetation and Water Depths in the Northern Everglades of Florida, USA(Waterbird Society, 2002-09) Bancroft, Thomas G.; Gawlik, Dale E.; Rutchey, KenItem Does a long-term shift in Wood Stork diet foreshadow adaptability to human-induced rapid environmental change?(Association of Field Ornithologists, 2018-04-10) Klassen, Jessica A.; Gawlik, Dale E.Geographically isolated wetlands (GIWs) have been increasingly recognized for their importance in providing ecosystem services, including support of regional biodiversity. These wetlands serve as valuable foraging and breeding habitat for wetland-dependent species, including wading birds. In certain regions of the U.S. Southeastern Coastal Plain approximately two-thirds of GIWs are impacted by adjacent human land use. We quantified wading bird density in agricultural and natural GIWs to determine the factors influencing their use of these habitats. Using monthly transect surveys, we found that wetland specific variables, including prey abundance and size, wetland surface area, and dry-down rate, were better predictors of wading bird density than landscape level variables such as wetland density and distance to breeding colony. Bird density was highest in agricultural wetlands early in the hydroperiod, but as GIWs dried down, density dropped in agricultural wetlands and rose in natural wetlands. Collectively, these results suggest that wading birds in the Coastal Plain rely on a matrix of both agricultural and natural wetlands, and their use of wetlands varies temporally, peaking in late spring, to maximize prey availability. The seasonal process of receding water levels in GIWs and subsequent concentration of aquatic fauna provides important food resources for nesting wading birds.Item Dynamic habitat selection by two wading bird species with divergent foraging strategies in a seasonally fluctuating wetland.(The American Ornithologists' Union, 2011-10-01) Beerens, James M.; Gawlik, Dale E.; Herring, Garth; Cook, Mark I.Seasonal and annual variation in food availability during the breeding season plays an influential role in the population dynamics of many avian species. In highly dynamic ecosystems like wetlands, finding and exploiting food resources requires a flexible behavioral response that may produce different population trends that vary with a species’ foraging strategy. We quantified dynamic foraging-habitat selection by breeding and radiotagged White Ibises (Eudocimus albus) and Great Egrets (Ardea alba) in the Florida Everglades, where fluctuation in food resources is pronounced because of seasonal drying and flooding. The White Ibis is a tactile “searcher” species in population decline that specializes on highly concentrated prey, whereas the Great Egret, in a growing population, is a visual “exploiter” species that requires lower prey concentrations. In a year with high food availability, resource-selection functions for both species included variables that changed over multiannual time scales and were associated with increased prey production. In a year with low food availability, resource-selection functions included short-term variables that concentrated prey (e.g., water recession rates and reversals in drying pattern), which suggests an adaptive response to poor foraging conditions. In both years, the White Ibis was more restricted in its use of habitats than the Great Egret. Real-time species–habitat suitability models were developed to monitor and assess the daily availability and quality of spatially explicit habitat resources for both species. The models, evaluated through hindcasting using independent observations, demonstrated that habitat use of the more specialized White Ibis was more accurately predicted than that of the more generalist Great Egret.Item The ecological–societal underpinnings of Everglades restoration(The Ecological Society of America, 2005) Sklar, Fred H.; Chimney, Michael J.; Newman, Susan; McCormick, Paul; Gawlik, Dale; Miao, ShiLi; Mc Voy, Christopher; Said, Winifred; Newman, Jana; Coronado, Carlos; Crozier, Gaea; Korvela, Michael; Rutchey, KenThe biotic integrity of the Florida Everglades, a wetland of immense international importance, is threatened as a result of decades of human manipulation for drainage and development. Past management of the system only exacerbated the problems associated with nutrient enrichment and disruption of regional hydrology. The Comprehensive Everglades Restoration Plan (CERP) now being implemented by Federal and State governments is an attempt to strike a balance between the needs of the environment with the complex management of water and the seemingly unbridled economic growth of southern Florida. CERP is expected to reverse negative environmental trends by “getting the water right”, but successful Everglades restoration will require both geochemical and hydrologic intervention on a massive scale. This will produce ecological trade-offs and will require new and innovative scientific measures to (1) reduce total phosphorus concentrations within the remaining marsh to 10 μg/L or lower; (2) quantify and link ecological benefits to the restoration of depths, hydroperiods, and flow velocities; and (3) compensate for ecological, economic, and hydrologic uncertainties in the CERP through adaptive management.