9. Conclusions and Summary

9. Conclusions and Summary

Thankfully this limited damage to the present office. However, most other buildings were damaged significantly (work shop, lumber shed, airboat sheds, dormitories, etc). Numerous structures were entirely washed away, including the field laboratory which many CSG members have used over the years. Over half the staff at Rockefeller lost their entire homes, and most others have extensive damage which will take months or years to repair. The entire staff was displaced from their homes, but were all rapidly back to work (albeit with lengthy commutes from 50-60 miles away). Plans are underway to repair and rebuild with improvements and continue the work done there in marsh enhancement, and research and management of alligators, waterfowl, and fisheries resources. Flooded workshop and office building Damaged and flooded alligator at Rockefeller Headquarters holding tanks 26 September 2005 (two days after landfall) By February 2006, we were able to resume field research on alligators, and initiated several studies as described above, as well as other collaborative studies not mentioned herein. Temporary storage buildings were moved on-site and a temporary laboratory and alligator holding facilities have been established. 9. Conclusions and summary While the narrative above can only review general observations on hurricane effects noted thus far, our main concerns are vegetative changes and habitat loss due to the massive coastwide storm surge brought on by both hurricanes, made worse by lack of rainfall and inability to drain off trapped saltwater for months after the hurricanes. Louisiana is fortunate to have over 4 million acres of excellent alligator habitat, which should provide haven for alligators pushed temporarily away from their normal range by the storm surge. Annual coastal nesting surveys will be done in late June and early July 2006, and will give us a better index of marsh recovery or possibly document habitat loss, if present. The long term effects of these habitat alterations remain to be seen; fortunately alligators are resilient and we are optimistic that populations will recover from the direct mortality seen from both storms, which is difficult to quantify. 277 Our wild egg “ranching” program has long been considered a success in wildlife management. This was even more pronounced in 2005, as a record 507,315 wild alligator eggs were collected and incubated at commercial alligator farms. Certainly a large portion of these would have died from flooding or loss of hatchlings with saltwater inundation immediately post-storms had they not been collected as part of the egg ranching program. This clearly illustrates the benefits of sustained use management. Louisiana’s annual wild autumn alligator harvest was a success in 2005, despite setbacks from both storms. We anticipate when all hides have been shipped that some 85% of the CITES tags issued will have been used; which is remarkable as so many of the trappers involved reside in coastal parishes and were forced to evacuate, and were displaced due to the hurricanes. We plan to maintain an active harvest program as our annual surveys dictate and see no immediate changes in the structure of our successful wild harvest. Quotas will continue to be established based on annual nesting surveys, analyses of the nesting survey data from the five most recent years, size classes and sex ratios taken in the annual harvest, and night count surveys. Alligator farmers and ranchers suffered very limited “on farm” mortality of live alligators (1.36%). Despite large economic losses of equipment and facilities, affected farmers and ranchers rapidly resumed operations and with essentially no interruption in production of hides, which was maintained through the initial recovery period. The alligator research program centered at Rockefeller Wildlife Refuge in Grand Chenier was affected by loss of the field laboratory and extensive damage to the alligator incubators and holding facilities. The office was essentially spared, as were all records and data. As soon as staff members were able to safely return and begin field work, surveys and collections of alligators to evaluate hurricane effects were initiated. Numerous collaborative projects are underway and we plan to rebuild and upgrade the research facility. Analyses of samples from several projects related to hurricane effects on alligators are pending, including plasma corticosterone and electrolyte levels, tissue samples for heavy metals and contaminants, general health profiles from serology, and dispersal studies from alligators marked and tagged prior to the hurricanes. As noted, some of these will be difficult to interpret, as they may be due to the superimposed drought which has developed in the months following the hurricane, and could be a result of either stressor. 10. Acknowledgements We thank numerous LDWF employees who collected salinity data and assisted in capture of alligators at night for blood sampling, including Phillip “Scooter” Trosclair, Dwayne LeJeune, Jeb Linscombe, and George Melancon. We appreciate Dr. Mark Merchant’s generous loan of lab supplies, use of his lab and freezer space for the first two sampling trips, and help catching alligators in late February. Brandy Williams provided technical expertise in preparation of the manuscript. 278 11. Literature Cited Ensminger, Allan B. and L. G. Nichols. 1957. Hurricane damage to Rockefeller Refuge. Proc. Ann. Conf. SE Game Fish Comm. 11: 52-56. Elsey, R. M., L. McNease, and T. Joanen. 2001. Louisiana’s alligator ranching program: a review and analysis of releases of captive-raised juveniles. In: Crocodilian Biology and Evolution. G. Grigg, F. Seebacher, and C. E. Franklin (eds). pp 426-41. Surrey Beatty & Sons, Chipping Norton. Elsey, R. M., V. Lance, and P. L. Trosclair, III. 2004. Abstract. Evidence for long- distance migration by wild American alligators. Proceedings of the 17th Working Meeting of the IUCN-SSC Crocodile Specialist Group. Darwin, Northern Territory of Australia. May 24-29, 2004. pg 70. Elsey, R. M. 2005. Unusual offshore occurrence of an American alligator. Southeastern Naturalist. 4(3):533-536. Joanen, T. and L. McNease. 1972. Salinity tolerance of hatchling alligators. Pg. 56-57 in Louisiana Wildlife and Fisheries Commission 14th Biennial Report 1970-1971. Joanen, T., L. McNease, and G. Perry. 1977. Effects of simulated flooding on alligator eggs. Proc. Ann. Conf. SE Game Fish Comm. 31:33-35. Lance, V. A. and Lauren, D, J. 1984. Circadian variation in plasma corticosterone in the American alligator, Alligator mississippiensis, and the effects of ACTH injection. Gen. Comp. Endocrinol. 54:1-7. Lance, V. A., L. A. Morici, and R. M. Elsey. 2001. Physiology and endocrinology of stress in crocodilians. In: Crocodilian Biology and Evolution. G. Grigg, F. Seebacher, and C. E. Franklin (eds). 327-40. Surrey Beatty & Sons, Chipping Norton. Lauren, D. J. 1985. The effect of chronic saline exposure on the electrolyte balance, nitrogen metabolism, and corticosterone titer in the American alligator, Alligator mississippiensis. Comp. Biochem. Physiol. 81A(2):217-223. Morici, L. A. 1996. Endocrine and physiological response to osmotic stress in the American alligator, Alligator mississippiensis. MS thesis, University of San Diego. 145 pp. Presley, S. M., T. R. Rainwater, G. P. Austin, S. G. Platt, et al. 2006. Assessment of pathogens and toxicants in New Orleans, LA following Hurricane Katrina. Environ. Sci. Technol. 40:468-474. ----- 279 Status And Monitoring Of The American Alligator In The Everglades Of Southern Florida, USA Kenneth G. Rice 1, Frank J. Mazzotti2 , H. Franklin Percival3, Michael S. Cherkiss2, and Laura A. Brandt4 1U.S. Geological Survey, Florida Integrated Science Center, Davie, FL, 33314, USA ([email protected]); 2University of Florida, Department of Wildlife Ecology and Conservation, Fort Lauderdale, FL, 33314, USA ([email protected], [email protected]) 3U.S. Geological Survey, Florida Cooperative Fish and Wildlife Research Unit, Gainesville, FL, 32611, USA ([email protected]) 4U.S. Fish and Wildlife Service, Arthur R. Marshall Loxahatchee National Wildlife Refuge, Boynton Beach, FL, 33437, USA ([email protected]) Abstract: The American Alligator (Alligator mississippiensis) was abundant in the pre-drainage Everglades of southern Florida, USA. Alligators once occupied all wetland habitats in South Florida, from sinkholes and ponds in pinelands to mangrove estuaries during periods of freshwater discharge (Craighead 1968, Simmons and Ogden 1998). Nearly all aquatic life in the Everglades is affected by alligators in some way (Beard 1938). As a top predator in their ecosystem, alligators undergo an extraordinary change in body size, consuming different prey items as they grow (Mazzotti and Brandt 1994). As ecosystem engineers, alligators create trails and holes that provide aquatic refugia during the dry season and concentrate food items for larger predators. Alligator nests provide elevated areas for nests of turtles and snakes, and for germination of plants less tolerant of flooding (Craighead 1971, Kushlan and Kushlan 1980, Enge et al. 2000). Alligator activity also keeps many small creeks in the freshwater mangrove zone, alligator holes, and areas around tree islands from becoming overgrown with vegetation. It is possible that alligator activity creates firebreaks providing protection for woody vegetation and various animal species (Craighead 1968, Simmons and Ogden 1998). Water present in holes during the dry season provides critical

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