Current Search:  Beerens, James M. (x)

View All Items

  • CSV Spreadsheet
(1 - 5 of 5)
Linking Dynamic Habitat Selection with Wading Bird Foraging Distributions across Resource Gradients
Title
Linking Dynamic Habitat Selection with Wading Bird Foraging Distributions across Resource Gradients.
Creator
Beerens, James M., Noonburg, Erik G., Gawlik, Dale E., Gao, Chang-Qing
Date Issued
2015-06-24
PURL
http://purl.flvc.org/fau/fd/FAUIR000142
Format
Citation
Hierarchical resource selection and movement of two wading bird species with divergent foraging strategies in the Everglades
Title
Hierarchical resource selection and movement of two wading bird species with divergent foraging strategies in the Everglades.
Creator
Beerens, James M., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Seasonal variation in food availability is one of the primary limitations to avian populations, particularly during the breeding season. However, the behavioral responses between species may differ based on foraging strategies. I examined the influence of food availability on landscape-level habitat selection, patch-level habitat selection, and movements of two wading bird species with divergent foraging strategies, the Great Egret and White Ibis. On a landscape scale, there appeared to be a...
Show moreSeasonal variation in food availability is one of the primary limitations to avian populations, particularly during the breeding season. However, the behavioral responses between species may differ based on foraging strategies. I examined the influence of food availability on landscape-level habitat selection, patch-level habitat selection, and movements of two wading bird species with divergent foraging strategies, the Great Egret and White Ibis. On a landscape scale, there appeared to be a relationship among resource availability, the temporal scale of the independent variable, and whether the response was similar or different between species. At the patch level, results demonstrated a relationship between resource availability and the spatial scale of the independent variables selected by birds. Species movements were consistent with the differing strategies. This study is the first to make the link between landscape hydrology patterns, prey availability, and responses in wading bird habitat selection at multiple spatial scales.
Show less
Date Issued
2008
PURL
http://purl.flvc.org/FAU/172667
Subject Headings
Water birds, Habitat, Habitat selection, Bird populations, Wetland ecology
Format
Document (PDF)
Physiological Condition of Juvenile Wading Birds in Relation to Multiple Landscape Stressors in the Florida Everglades: Effects of Hydrology, Prey Availability, and Mercury Bioaccumulation
Title
Physiological Condition of Juvenile Wading Birds in Relation to Multiple Landscape Stressors in the Florida Everglades: Effects of Hydrology, Prey Availability, and Mercury Bioaccumulation.
Creator
Herring, Garth, Eagles-Smith, Collin A., Gawlik, Dale E., Beerens, James M., Ackerman, Joshua T., Gao, Chang-Qing
Abstract/Description
The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey...
Show moreThe physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (shortterm index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.
Show less
Date Issued
2014-09-03
PURL
http://purl.flvc.org/fau/fd/FAUIR000064
Format
Citation
Development, evaluation, and application of spatio-temporal wading bird foraging models to guide everglades restoration
Title
Development, evaluation, and application of spatio-temporal wading bird foraging models to guide everglades restoration.
Creator
Beerens, James M., Noonburg, Erik G., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
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...
Show moreIn 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.
Show less
Date Issued
2014
PURL
http://purl.flvc.org/fau/fd/FA00004078, http://purl.flvc.org/fau/fd/FA00004078
Subject Headings
Everglades National Park (Fla.) -- Environmental conditions, Restoration ecology -- Florida -- Everglades National Park, Water birds -- Florida -- Geographical distribution, Water birds -- Habitat -- Florida -- Everglades National Park, Wetland restoration -- Florida -- Everglades National Park
Format
Document (PDF)
Determining habitat quality for species that demonstrate dynamic habitat selection
Title
Determining habitat quality for species that demonstrate dynamic habitat selection.
Creator
Beerens, James M., Frederick, Peter C., Noonburg, Erik G., Gawlik, Dale E.
Date Issued
2015-11-19
PURL
http://purl.flvc.org/fau/fd/FAUIR000141
Format
Citation