Southeastern Naturalist L. Rodgers 2017 ii Vol. 15, Special Issue 8 Everglades Invasive Species Special Issue: Introduction and Overview LeRoy Rodgers* America’s Everglades is the largest subtropical wetland ecosystem in North America. The ~46,620-km2 (18,000-mi2) landscape comprises a unique mix of low marshes, sloughs, and shrub-dominated vegetation, scattered tropical forests, and extensive cypress swamps. Following decades of ecosystem degradation caused by flood-control projects and sprawling development, the Everglades is now the site of the world’s largest ecosystem-restoration effort (WRDA 2000). While restoration efforts primarily emphasize improving the quantity, quality, and timing of water conveyance to the Everglades, curbing invasive exotic species has been widely recognized by partner agencies and other stakeholders as having an important role in restoration (NRC 2014, SFERTF 2015). These concerns are based in part on the remarkably high number of non-indigenous species established in southern Florida and the presumption that historical disturbance regimes (e.g., altered hydroperiods, nutrient enrichment) are not the sole mechanisms for biological invasions (Lake and Leishman 2004, Liu and Stiling 2006) in the Everglades. Early management efforts focused on a handful of widely established, highly aggressive invasive plant species. Interagency efforts to reduce the impact of Melaleuca quiquenervia (Cav.) S.T. Blake (Melaleuca or Paperbark Tree) began in earnest in the early 1980s. At the time, Melaleuca was estimated to occupy a 165,516- ha range in southern Florida, with 16,308 ha as dense monotypic stands (Cost and Craver 1981). The concerted, 30-year effort, which integrated research, control efforts, public education, and regulatory tools, is considered a success story in invasive species management; Melaleuca is now controlled at low levels across much of its previous range in the Everglades. (Center et al. 2012, Rodgers et al. 2014). Unfortunately, many other non-indigenous species did not receive comparable attention during the early years of Everglades restoration. Not until news of the Everglades’ infamous invasion by Python bivittatus Kuhl (Burmese Python) in the early 2000s did attention to invasive exotic animals gain significant momentum. The increasing awareness of Florida’s abundant non-indigenous fauna also coincided with greater appreciation among stakeholders of the benefits, both environmental and economic, of preventing new invasions and addressing newly established species rapidly. To encourage new research into the natural history and management approaches for invasive exotic species, stakeholders have advocated for increased funding towards management-driven investigations (ELI 2004, Lodge et al. 2006, SFERTF 2015). Natural resource managers and decision makers rely on such investigations *South Florida Water Management District, West Palm Beach, FL 33406; lrodgers@sfwmd. gov. Everglades Invasive Species 2017 Southeastern Naturalist 15(Special Issue 8):ii–vi Southeastern Naturalist iii L. Rodgers 2017 Vol. 15, Special Issue 8 to help inform and refine integrated management strategies. This volume represents the latest research concerning 6 invasive species now established in the Everglades and evaluations of recent citizen science and outreach programs. The wide range of taxa and management components highlighted in this issue exemplify the broad spectrum of invasive species challenges faced by stewards of the Everglades. Five papers in this issue present ecology and life-history findings for 4 invasive exotic species established in the Everglades. Basic natural history information is often lacking when a non-indigenous species is first targeted for management, making it difficult to develop sound control strategies. In this issue, Callahan and Gawlick (2016) evaluate diet patterns of the non-native Porphyrio porphyrio (L.) (Purple Swamphen) in southern Florida and discuss the implications for population regulation and potential geographic range of this invasive rallid. Hanslowe et al. (2016) report on the utilization of human structures by brooding Burmese Pythons. The authors discuss the significance of this behavior with regard to potential expansion of Burmese Pythons northward and into urban areas. Wolf et al. (2016) report on incubation temperature and sex ratio of a Burmese Python clutch monitored in Everglades National Park. Smith et al. (2016) provide the first study on the reproductive biology of Furcifer oustaleti (Mocquard) (Oustalet’s Chameleon) in southern Florida, providing valuable data on the seasonality of reproduction, nestsite characteristics, clutch size, egg characteristics, and incubation periods. Eckles et al. (2016) describe the first confirmed reproducing population of Varanus niloticus (L.) (Nile Monitor) in southeastern Florida, a relatively short distance from the northern reaches of the Everglades. In addition to a confirmed reproducing population in Cape Coral in southwestern Florida and observations of Nile Monitors in Miami-Dade and Broward counties, this newly documented population indicates that this large, carnivorous lizard is expanding its range in South Florida. These papers are significant contributions to our understanding the ecology and life history of 4 established invasive species in the Everglades and are certain to help inform development of effective management strategies. Another research area critical for managing invasive species is the development and testing of control methodologies. Suppressing or eradicating invasive species in sensitive natural areas presents unique and often daunting challenges because most control tools are not species-specific. As such, there are rarely turnkey control solutions for newly detected invaders. In this issue, Sebesta et al. (2016) evaluate the effect of prescribed fire on spore viability of Lygodium microphyllum (Cav.) R. Br. (Old World Climbing Fern). Their research quantifies the lower limit of fire temperatures and durations required to significantly reduce spore viability, furthering our understanding of prescribed fire as a potential control tool for this highly invasive climbing fern. Biological control of invasive plants is an important component of integrated invasive species management in natural areas. Wheeler et al. (2016) report on the latest efforts to identify suitable biological control agents for the most widespread and abundant invasive plant in the Everglades—Schinus terebinthifolia Raddi (Brazilian Peppertree). Results of choice and no-choice trials of 2 promising agents, the thrips Pseudophilothrips ichini (Hood) (Thysanoptera: Southeastern Naturalist L. Rodgers 2017 iv Vol. 15, Special Issue 8 Phlaeothripidae) and the foliage-gall–former Calophya latiforceps Burckhardt (Hemiptera: Calophyidae) are presented. The recently established Salvator merianae A.M.C. Duméril & Bibron (Argentine Black and White Tegu) is currently the focus of a state-wide interagency management effort. Trapping is considered a viable control option for this large-bodied lizard, but relatively little is known about the efficacy of various trap designs. Avery et al. (2016) evaluate several alternative trap and bait combinations on captive tegus. This research provides preliminary findings on the propensity of tegus to enter numerous trap designs, including simple and inexpensive prototypes. Citizen participation in invasive species control efforts can promote public understanding of the role of human behavior in biological invasions (Merenlender et al. 2016) and leverage public interest towards management solutions (Dickinson et al. 2012). In this issue, Falk et al. (2016) provide a case study on citizen scientist participation in Burmese Python management in Everglades National Park, highlighting the benefits and challenges of such programs. Mazzotti et al. (2016) provide results and analysis of the 2013 Python Challenge®, a public competition developed by the Florida Fish and Wildlife Conservation Commission to raise awareness about Burmese Pythons, increase public participation, increase knowledge of python ecology, and examine effectiveness of incentives to increase public participation in invasive wildlife management. Wallace et al. (2016) report on a collaboration between the Center for Invasive Species and Ecosystem Health (Bugwood) and the Everglades Cooperative Invasive Species Management Area to develop tools to improve data sharing and distribute outreach materials to increase public involvement. These programs have contributed significantly to stakeholder awareness of the numerous invasive species currently established in South Florida and provide insight into the benefits and challenges of citizen science programs. All involved in the creation of this issue hope it will inspire further investigations into the complex and varied challenges of biological invasions in America’s Everglades. Deepening our understanding of the consequences of biological invasions, identifying the most harmful invaders, and developing effective methods to control invasive species is paramount as we move forward with Everglades restoration. As a former Department of Interior scientist, Bob Doren, compellingly inquired to the South Florida Ecosystem Restoration Task Force (13 November 2000), “We may ‘get the water right’, but if we fail to address invasive species will we have the Everglades when restoration is complete?” Literature Cited Avery, M.L., J.S. Humphrey, and R.M. Engeman. 2016. Evaluating trap alternatives for removal of Salvator merianae (Black and White Tegu). Southeastern Naturalist 15(Special Issue 8):107–113. Callaghan, C.T., and D.E. Gawlik. 2016. Diet and selectivity of Porphyrio porphyrio (Purple Swamphen) in Florida. Southeastern Naturalist 15(Special Issue 8):1–14. Center, T.D., M.F. Purcell, P.D. Pratt, M.B. Rayamajhi, P.W. Tipping, S.A. Wright, and F.A. Dray Jr. 2012. Biological control of Melaleuca quinquenervia: An Everglades invader. Biocontrol 57:151–165. Southeastern Naturalist v L. Rodgers 2017 Vol. 15, Special Issue 8 Cost, N.D., and G.C. Craver. 1981. Distribution of Melaleuca in South Florida measured from the air. [PROVIDE PAGE #S], In R.K. Geiger, (Ed.). Proceedings of the Melaleuca Symposium, September 23–24, 1980. Division of Forestry, Florida Department of Agricultural and Consumer Services, Tallahassee, FL. Dickinson J.L., J. Shirk, D. Bonter, R. Bonney, R.L. Crain, J. Martin, T. Phillips, and K. Purcell. 2012. The current state of citizen science as a tool for ecological research and public engagement. Frontiers in Ecology and the Environment 10:291–297. Environmental Law Institute (ELI). 2004. Filling the gaps: Ten strategies to strengthen invasive species management in Florida. Available online at https://www.eli.org/sites/ default/files/eli-pubs/fillingthegaps.pdf. Accessed 14 December 2016. Falk, B.G., R.W. Snow, and R.N. Reed. 2016. Prospects and limitations of citizen science in invasive species management: A case study with Burmese Pythons in Everglades National Park. Southeastern Naturalist 15(Special Issue 8):89–102. Hanslowe, E.B., B.G. Falk, M.A.M. Collier, J.M. Josimovich, T.A. Rahill, and R.N. Reed. 2016. First record of invasive Burmese Python oviposition and brooding inside an anthropogenic structure. Southeastern Naturalist 15(Special Issue 8):103–106. Lake, J.C., and M.R. Leishman. 2004. Invasion success of exotic plants in natural ecosystems: The role of disturbance, plant attributes, and freedom from herbivores. Biological Conservation 117:215–226. Liu, H., and P. Stiling. 2006. Testing the enemy release hypothesis: A review and metaanalysis. Biological Invasions 8:1535–1545. Lodge, D.M., S. Williams, H.J. MacIsaac, K.R. Hayes, B. Leung, S. Reichard, R.N. Mack, P.B. Moyle, M. Smith, D.A. Andow, and J.T. Carlton. 2006. Biological invasions: Recommendations for US policy and management. Ecological Applications 16(6):2035–2054. Mazzotti, F.J., M. Rochford, J. Vinci, B.M. Jeffery, J. Ketterlin Eckles, C. Dove, and K.P. Sommers. 2016. Implications of the 2013 Python Challenge® for ecology and management of Python molorus bivittatus (Burmese Python) in Florida. Southeastern Naturalist 15(Special Issue 8):51–62. Merenlender, A.M., A.W. Crall, S. Drill, M. Prysby, and H. Ballard. 2016. Evaluating environmental education, citizen science, and stewardship through naturalist programs. Conservation Biology 30:1255–1265. National Research Council (NRC ). 2014. Progress toward restoring the Everglades: The fifth biennial review. National Academies Press, Washington, DC. Available online at https://www.nap.edu/catalog/18809/progress-toward-restoring-the-everglades-thefifth- biennial-review-2014. Accessed 14 December 2016. Rodgers, L., D. Black, M. Bodle, and F. Laroche. 2014. Chapter 7: Status of nonindigenous species. Pp. 7-1–7-53, In 2014 South Florida environmental report. West Palm Beach, FL. 53 pp. Available online at http://www.sfwmd.gov/portal/page/portal/ pg_grp_sfwmd_sfer/portlet_prevreport/2014_sfer/v1/chapters/v1_ch7.pdf. Accessed 14 December 2016. Sebesta, N., J. Richards, and J. Taylor. 2016. The effects of heat on spore viability of Lygodium microphyllum and implications for fire management. Southeastern Naturalist 15(Special Issue 8):40–50 South Florida Ecosystem Restoration Task Force (SFERTF). 2015. Invasive exotic species strategic action framework. Available online at https://evergladesrestoration.gov/content/ ies/ Accessed 6 January 2017. Smith, D.J. Vinci, C.V. Anderson, J. Ketterlin Eckles, F. Ridgley, and F.J. Mazzotti. 2016. Observations on nesting and clutch size in Furcifer oustaleti (Oustalet’s Chameleon) in South Florida. Southeastern Naturalist 15(Special Issue 8):75–88. Southeastern Naturalist L. Rodgers 2017 vi Vol. 15, Special Issue 8 Wallace, R.D., C.T. Bargeron, D.J. Moorhead, and J.H. LaForest. 2016. IveGot1: Reporting and tracking invasive species in Florida. Southeastern Naturalist 15(Special Issue 8):51–62. Water Resources Development Act (WRDA). 2000. Pub. L. 106-541, Title IV Section 601(b)(1)(A). Available online at https://www.gpo.gov/fdsys/pkg/PLAW-106publ541/ html/PLAW-106publ541.htm. Accessed January 2017. Wheeler, G.S., F. Mc Kay, M.D. Vitorino, V. Manrique, R. Diaz, and W.A. Overholt. 2016. Biological control of the invasive weed Schinus terebinthifolia (Brazilian Peppertree): A review of the project with an update on the proposed agents. Southeastern Naturalist 15(Special Issue 8):15–34. Wolf, A.J., T.M. Walters, M.R. Rochford, R.W. Snow, and F.J. Mazzotti. 2016. Incubation temperature and sex ratio of a Python bivittatus (Burmese Python) clutch hatched in Everglades National Park, Florida. Southeastern Naturalist 15(Special Issue 8):35–39.