Translocation of Radio-implanted Eastern tiger salamanders (Ambystoma tigrinum tigrinum) at Brookhaven National Laboratory

2 Introduction.4 Materials and Methods.8 Results.9 Discussion and Conclusion.10 Acknowledgements.12 References.12 Tables.14 Figures.14 ABSTRACT A way to combat deteriorating upland habitat that surrounds amphibian breeding ponds is the translocation of jeopardized species to restored wetlands. Information on movement patterns of translocated individuals is crucial to comprehending the ecology of a species by detecting any detrimental effects the translocation has on the individual. This type of knowledge is vital when making management decisions regarding land use. Although the indigenous range stretches from Long Island down to northern Florida, the eastern tiger salamander is a New York state endangered amphibian found on New York’s Long Island. This amphibian species is affected by increased urbanization that threatens its breeding habitat. This status makes this species a worthy candidate of translocation to suitable habitat. In an effort to determine the impact of translocation on this particular species, eleven eastern tiger salamander juveniles were collected from two different ponds, Pond A and Pond B, and surgically implanted with radio transmitters. This implantation allowed for the tracking of movement patterns after pond emergence. Five individuals from Pond A were translocated to Pond B, while five were returned to Pond A. The individual collected from Pond B was implanted and returned to its collection site. All individuals were radio-tracked for four weeks to determine movement patterns and habitat selection through the recording of vegetation in a plot surrounding the individual’s location. OfA way to combat deteriorating upland habitat that surrounds amphibian breeding ponds is the translocation of jeopardized species to restored wetlands. Information on movement patterns of translocated individuals is crucial to comprehending the ecology of a species by detecting any detrimental effects the translocation has on the individual. This type of knowledge is vital when making management decisions regarding land use. Although the indigenous range stretches from Long Island down to northern Florida, the eastern tiger salamander is a New York state endangered amphibian found on New York’s Long Island. This amphibian species is affected by increased urbanization that threatens its breeding habitat. This status makes this species a worthy candidate of translocation to suitable habitat. In an effort to determine the impact of translocation on this particular species, eleven eastern tiger salamander juveniles were collected from two different ponds, Pond A and Pond B, and surgically implanted with radio transmitters. This implantation allowed for the tracking of movement patterns after pond emergence. Five individuals from Pond A were translocated to Pond B, while five were returned to Pond A. The individual collected from Pond B was implanted and returned to its collection site. All individuals were radio-tracked for four weeks to determine movement patterns and habitat selection through the recording of vegetation in a plot surrounding the individual’s location. Of the five individuals returned to their native pond, three were lost to predation, one died in the field, and one was lost when its signal became untraceable. The greatest distance traveled occurred by the salamanders placed at pond of original collection. Of the translocated individuals, four were preyed on. This may indicate that translocated individuals are more susceptible to predation. Additionally, translocated individuals at Pond B moved a shorter distance, in comparison to individuals at Pond A. This is indicative of stress and unfamiliarity with the area. Due to a very dry summer, Pond A dried up completely, prompting an early emergence of the salamanders at a smaller size, making these individuals more vulnerable to mortality. Although transience existed at both ponds it appears that Eastern tiger salamanders fare better when they are not translocated. With all the abiotic and biotic factors of each study site, more research is necessary to deem translocation a worthy way to manage the Eastern tiger salamander population of Long Island. INTRODUCTION The eastern tiger salamander (Ambystoma tigrinum tigrinum) is a widely distributed ambystomid species ranging from Northern Florida to Long Island, New York. Due to increased urbanization and the resulting loss of breeding habitat, the New York range of tiger salamanders is only on Long Island, in Suffolk County. Presently, this species is listed as Endangered in New York State [1]. In an effort to rectify this status, conserve and recover A. t. tigrinum in New York, management decisions are being made. In an effort to reduce risk of extinction, a recently popular way of managing populations of endangered species in areas where they have been extirpated has been translocation [2]. Translocation of jeopardized species to restored wetlands is an option of combating deteriorating habitat that surrounds amphibian breeding ponds. This method is viewed as a way to save a species in decline. The state-endangered status of this particular species makes it a worthy candidate for translocation. But first, information regarding the basic needs of this species and the monitoring of movement patterns is necessary to deem translocation a viable method of restoring a species. Amphibians can be found in similar areas throughout a given period and have specific habitat needs, such as vegetative structure, moisture requirements, and corridors for dispersal [2]. Translocation is believed to disrupt these movement patterns due to differences in habitat availability and familiarity. This research attempts to validate translocation of Eastern tiger salamanders as a conservation management strategy by evaluating the impact of translocation on movement patterns. This study expects to achieve information that will be necessary when making land use and species management decisions. MATERIALS AND METHODS Study area The study took place from 7 July 2008 to 7 August 2008 in Upton, Suffolk County, Long Island, New York on Brookhaven National Laboratory property. Two breeding ponds were selected based on the presence of egg masses in winter surveys. The selected ponds were within pitch pine (Pinus rigida) /oak (Quercus spp.) forest. Pond A was surrounded by grasses, forbs, and shrubs with one road bordering the southern edge of the pond. This pond is completely sun exposed and is subject to flooding and complete dryness, based on hydroperiod and rainfall accumulation. The average depth for this pond is 0.5 m. Aquatic vegetation included algae. Pond B was a more isolated pond more south of Pond A. This pond was also surrounded by grass, forbs with upland vegetation beginning 10 m from the pond edge. Aquatic vegetation was primarily cattails and lilies. This pond was deeper than Pond B, with the deepest part at 2.5 m. This pond is also sun exposed but does not dry up or flood as frequently as Pond A. Radiotelemetry Procedures Larval Eastern tiger salamanders (Ambystoma tigrinum) were initially captured from Pond A by seining the area. Ten individuals were collected from Pond A. One individual was collected from Pond B by dip netting instead of seining, due to the depth of the pond and its large amount of emergent vegetation. The animals were taken from the field in plastic containers to a laboratory for implant surgery. Surgery procedures followed those outlined by Madison [3] and Faccio [4]. For anesthesia, the salamanders were individually submerged into 0.25% solution of MS222 (3Aminobenzoic acid ester methanosulfate salt). Complete anesthesia occurred within 20 minutes, depending on body size and development of external gills. Holohil BD-2H 1.8g transmitters with internal antennas were implanted internally into the coelomic cavity of each animal at Brookhaven National Laboratory. After surgery, the salamanders were rinsed in distilled water and allowed to recover overnight in tanks of water. The salamanders were released 24 h after surgery. On 1 July 2008, five salamanders from Pond A were returned to Pond A at the pond’s edge, nearest their capture point. Five salamanders from Pond A were placed in Pond B for translocation. The individual from Pond B was returned to Pond B 2 July 2008. Over a four-week period, transmitter-implanted salamanders were tracked every 1-2 days at a consistent time using a Communications Specialist, INC model R1000 Telemetry Receiver. SporTrak Pro Global Positioning System (GPS) unit was used to collect position information on all tracked animals. A Kestrel 4000 was used to collect temperature, wind speed and humidity data. A 1 m plot was placed around the individual and the amount of trees, saplings, shrubs, patches of grass, forbs, ferns, moss, coniferous litter, deciduous litter and coniferous/deciduous litter was noted. Percent deciduous canopy and coniferous canopy was also noted, along with abiotic factors such as temperature, soil moisture and estimated distance from pond. Any peculiar item about the salamander’s location was noted, such as incidences of predation or other mortality. Analyses GPS waypoi