10.5061/DRYAD.J7049
Nifong, James C.
University of Florida
Layman, Craig A.
North Carolina State University
Silliman, Brian R.
Duke University
Data from: Size, sex, and individual-level behavior drive intra-population
variation in cross-ecosystem foraging of a top-predator
Dryad
dataset
2015
crocodilian
estuary
Alligator mississippiensis
ecosystem connectivity
present
trophic coupling
2015-10-07T00:00:00Z
2015-10-07T00:00:00Z
en
https://doi.org/10.1111/1365-2656.12306
16583522 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. Large-bodied, top-predators are often highly mobile, with the potential
to provide important linkages between spatially distinct food webs. What
biological factors contribute to variation in cross-ecosystem movements,
however, have rarely been examined. 2. Here, we investigated how ontogeny
(body size), sex, and individual-level behavior impacts intra-population
variation in cross-ecosystem foraging (i.e., between freshwater and marine
systems), by the top-predator Alligator mississippiensis. 3. Field surveys
revealed A. mississippiensis uses marine ecosystems regularly and are
abundant in estuarine tidal creeks (from 0.3–6.3 individuals/km of creek,
n = 45 surveys). Alligator mississippiensis captured in marine/estuarine
habitats were significantly larger than individuals captured in freshwater
and intermediate habitats. 4. Stomach content analysis showed that small
juveniles consumed marine/estuarine prey less frequently (6.7% of
individuals) than did large juveniles (57.8%), sub-adult (73%), and adult
(78%) size classes. Isotopic mixing model analysis (SIAR) also suggests
substantial variation in use of marine/estuarine prey resources with
differences among and within size classes between sexes and individuals
(range of median estimates for marine/estuarine diet contribution =
0.05–0.76). 5. These results demonstrate the importance of
intra-population characteristics (body size, sex, and individual
specialization) as key determinants of the strength of predator-driven
ecosystem connectivity resulting from cross-ecosystem foraging behaviors.
Understanding the factors which contribute to variation in cross-ecosystem
foraging behaviors will improve our predictive understanding of the
effects of top-predators on community structure and ecosystem function.
Alligator_Capture_Isotope_DataCapture information, biological data, and
isotopic data from individual Alligator mississippiensis captured during
this study.Alligator_GPS_Capure_Location_DataLatitude and Longitude of
capture locations for A. mississippiensisAlligator_Stomach_Content_DataA.
mississippiensis stomach content data.Alligator_Survey_DataNightlight
count survey dataPrey_Habitat_Isotope_Collection_Site_DataLatitude and
longitude of collecting sites for stable isotope samples of primary
producers and prey species.Prey_Isotope_DataStable isotope values
determined for prey species.Primary_Producer_Isotope_DataStable isotope
values determined for primary producer species.Salinity_DataWater salinity
during time of this study.SIAR_Posterior_Adult_DataSIAR posterior
distributions for adult alligators.SIAR_posterior_Sub_Adult_DataSIAR
posterior distributions for sub-adult
alligators.SIAR_posterior_Large_Juvenile_dataSIAR posterior distributions
for large juvenile alligators.SIAR_posterior_Small_Juvenile_DataSIAR
posterior distributions for small juvenile
alligatorsSIAR_Simple_Mean_Source_DataIsotope values determined for SIAR
sources calculated using simple mean across all prey
species.SIAR_Weighted_Source_Mean_DataIsotope values for SIAR sources
calculated using a weighted mean by recovered mass of
prey.Trophic_Enrichment_Factors_TEFsTrophic enrichment factors used in
SIAR analyses
Southeastern United States Coast