Florida Cooperative Fish and Wildlife Research Unit
http://hdl.handle.net/1834/17552
2024-03-29T12:05:36ZSurvival and Growth of American Alligator (Alligator mississippiensis) hatchlings after artificial incubation and repatriation
http://hdl.handle.net/1834/23063
Survival and Growth of American Alligator (Alligator mississippiensis) hatchlings after artificial incubation and repatriation
Temsiripong, Yosapong; Woodward, Allan R.; Ross, J. Perran; Kubilis, Paul S.; Percival, H. Franklin
Hatchling American Alligators (Alligator mississippiensis) produced from artificially incubatedwild eggs were returned to their natal areas (repatriated). We compared artificially incubated andrepatriated hatchlings released within and outside the maternal alligator’s home range with naturallyincubated hatchlings captured and released within the maternal alligator’s home range on Lake Apopka,Lake Griffin, and Orange Lake in Florida. We used probability of recapture and total length at approximatelynine months after hatching as indices of survival and growth rates. Artificially incubated hatchlings releasedoutside of the maternal alligator’s home range had lower recapture probabilities than either naturallyincubated hatchlings or artificially incubated hatchlings released near the original nest site. Recaptureprobabilities of other treatments did not differ significantly. Artificially incubated hatchlings wereapproximately 6% shorter than naturally incubated hatchlings at approximately nine months after hatching.We concluded that repatriation of hatchlings probably would not have long-term effects on populationsbecause of the resiliency of alligator populations to alterations of early age-class survival and growth rates ofthe magnitude that we observed. Repatriation of hatchlings may be an economical alternative to repatriationof older juveniles for population restoration. However, the location of release may affect subsequent survivaland growth.
2006-01-01T00:00:00ZScale-Dependent Habitat Selection
of Nesting Great Egrets and Snowy Egrets
http://hdl.handle.net/1834/23062
Scale-Dependent Habitat Selection
of Nesting Great Egrets and Snowy Egrets
Stolen, Eric D.; Collazo, Jaime A.; Percival, H. Franklin
Foraging habitat selection of nesting Great Egrets (Ardea alba) and Snowy Egrets (Egretta thula) wasinvestigated within an estuary with extensive impounded salt marsh habitat. Using a geographic information system,available habitat was partitioned into concentric bands at five, ten, and 15 km radius from nesting colonies to assessthe relative effects of habitat composition and distance on habitat selection. Snowy Egrets were more likely thanGreat Egrets to depart colonies and travel to foraging sites in groups, but both species usually arrived at sites thatwere occupied by other wading birds. Mean flight distances were 6.2 km (SE = 0.4, N = 28, range 1.8-10.7 km) forGreat Egrets and 4.7 km (SE = 0.48, N = 31, range 0.7-12.5 km) for Snowy Egrets. At the broadest spatial scale bothspecies used impounded (mostly salt marsh) and estuarine edge habitat more than expected based on availabilitywhile avoiding unimpounded (mostly fresh water wetland) habitat. At more local scales habitat use matched availability.Interpretation of habitat preference differed with the types of habitat that were included and the maximumdistance that habitat was considered available. These results illustrate that caution is needed when interpreting theresults of habitat preference studies when individuals are constrained in their choice of habitats, such as for centralplace foragers.
2007-01-01T00:00:00ZTemperature effects on Florida applesnail activity: implications for snail kite foraging
success and distribution
http://hdl.handle.net/1834/23060
Temperature effects on Florida applesnail activity: implications for snail kite foraging
success and distribution
Stevens, Amanda J.
The endangered Florida snail kite (Rostrhamlls sociaiJilis) feeds exclusively on applesnails(Pomacea pailiclosa), yet we lack direct observations that link applesnail behavior to snailkite foraging success. The purpose of our study was to evaluate the temperature-activityprofile of applesnails in the context of restricted foraging opportunities for snail kites.Applesnail activity was monitored in water temperatures ranging from 2-24
2002-01-01T00:00:00ZVegetation Effects on Fish Distribution in
Impounded Salt Marshes
http://hdl.handle.net/1834/23061
Vegetation Effects on Fish Distribution in
Impounded Salt Marshes
Stolen, Eric D.; Collazo, Jaime A.; Percival, H. Franklin
We compared the density and biomass of resident fish in vegetated andunvegetated flooded habitats of impounded salt marshes in the northern IndianRiver Lagoon (IRL) Estuary of east-central Florida. A 1-m2 throw trap was usedto sample fish in randomly located, paired sample plots (n = 198 pairs) over 5 seasonsin 7 impoundments. We collected a total of 15 fish taxa, and 88% of the fisheswe identified from the samples belonged to three species: Cyprinodon variegatus(Sheepshead Minnow), Gambusia holbrooki (Eastern Mosquitofish), and Poecilialatipinna (Sailfin Molly). Vegetated habitat usually had higher density and biomassof fish. Mean fish density (and 95% confidence interval) for vegetated and unvegetatedsites were 8.2 (6.7–9.9) and 2.0 (1.6–2.4) individuals m-2, respectively; meanbiomass (and 95% confidence interval) for vegetated and unvegetated sites were3.0 (2.5–3.7) and 1.1 (0.9–1.4) g m-2, respectively. We confirmed previous findingsthat impounded salt marshes of the northern IRL Estuary produce a high standingstock of resident fishes. Seasonal patterns of abundance were consistent with fishmoving between vegetated and unvegetated habitat as water levels changed in theestuary. Differences in density, mean size, and species composition of residentfishes between vegetated and unvegetated habitats have important implications formovement of biomass and nutrients out of salt marsh by piscivores (e.g., wadingbirds and fishes) via a trophic relay.
2009-01-01T00:00:00Z