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Project Work Plan

Department of Interior USGS GE PES

Fiscal Year 2010 Study Work Plan

Study Title: Development of control tools for invasive pythons in Greater Everglades ecosystems
Study Start Date: October 1, 2007 Study End Date: September 30, 2011
Location (Subregions, Counties, Park or Refuge): Total System
Funding Source: USGS Greater Everglades PES (GE PES) (FY10)
Other Complementary Funding Source(s): Interdiction and control of invasive Burmese Pythons on Key Largo USFWS-ES (FY10)
Funding History: GE PES FY07-FY09
Principal Investigator(s): Robert N. Reed, Gordon H. Rodda, Kristen Hart
Project Personnel: Skip Snow (ENP), Ron Rozar, Scott Goetz (USGS), Frank Mazzotti, Michael Cherkiss (UFL), additional seasonal/term employees
Supporting Organizations: National Park Service - Everglades National Park, University of Florida, US Fish and Wildlife Service, South Florida Water Mgmt District

Overview & Objective(s): The Burmese Python (Python molurus) is native to south and southeast Asia, and is very popular in the international live animal trade. A burgeoning invasive population of these snakes, likely originating from released pets, is now present and expanding in the greater Everglades ecosystem. This population is continuing its northward expansion at a rapid pace, and has already moved well beyond the boundaries of NPS lands. The recent discovery of a Burmese Python on Key Largo containing two ESA-listed Key Largo woodrats implies that the python is able to cross saltwater, and may threaten to colonize the rest of the Florida Keys. While the existence of high-density populations of a large-bodied invasive predator is of obvious conservation concern, only slight progress has been made towards development of appropriate control tools for Burmese Pythons. Multiple state and federal agencies have expressed the urgent need for control tool development, with several requests for assistance from Everglades National Park and the U.S. Fish and Wildlife Service. For over two decades, the USGS Brown Treesnake Project has focused on development and operational assessment of control tools for invasive snakes, and is thus a logical choice for development of control tools for invasive Burmese Pythons. This project will focus on designing and assessing the efficacy of several trap types for capturing Burmese Pythons, with the goal of applying results to control of pythons in Everglades National Park, Big Cypress National Monument, Key Largo, and elsewhere.

Specific Relevance to Major Unanswered Questions and Information Needs Identified:

  • This study was originally initiated in response to an urgent request from U.S. Fish and Wildlife Service - Endangered Species Division (contact person: Sandra Sneckenberger, phone 772-562-3909) and the National Park Service (Everglades National Park, contact person Skip Snow, phone 305-242-7827) to develop traps and other control tools for estimating python population size and initiating python control efforts in south Florida. These invasive snakes may have major detrimental effects on many state- and federally-listed vertebrate species that are suitable as prey for pythons. For example, Key Largo is home to two endemic ESA-listed small mammals (Key Largo woodrat and Key Largo cotton mouse) that are potentially vulnerable to invasion by pythons, and several pythons containing Key Largo woodrats have been found on Key Largo thus far. By initiating control efforts on Key Largo as well as conducting trap efficacy trials and control efforts in mainland habitats with higher densities of pythons, this study will result in a more robust sample size of captured snakes, facilitating more rigorous data analysis and prescriptions for python control with respect to trapping.
  • This study supports the Comprehensive Everglades Restoration Plan goal of restoring Everglades ecosystems by control and removal of invasive species.
  • This study addresses several science objectives in the USGS Science Plan in Support of Everglades Restoration. Primarily, this work is concentrated under Goal 2B "Restore, Preserve, and Protect Natural Habitats and Species - Ecological Indicators." Specifically, results of trapping efforts, combined with existing data from NPS, USGS, and U. Florida, will help establish baseline estimates of population size and demographic profiles of Burmese Pythons in areas selected for intensive trapping. These estimates can be used for future monitoring programs (2B-SG3), and will guide development of such programs for evaluating restoration success (2B-SG4).
  • The proposed project responds to needs stated in the BAA and DOI Science Plan for research to develop effective control methods for exotic aquatic vertebrates, for research into the life history of non-native species, and to determine impacts of exotic species on native species on federally managed lands. Specific projects that could affect the ultimate distribution and abundance of pythons in southern Florida include the Combined Structural and Operational Plan (CSOP) for modified water deliveries to Everglades National Park and Decompartmentalization of Water Conservation Area 3 (Decomp).
  • Potential Impacts: As do other non-native aquatic species, Burmese Pythons present a potential threat to successful ecological restoration of the greater Everglades (NRC 2005). Pythons are now established and breeding in South Florida, with nearly 1,000 individuals captured thus far and an estimated detection probability of ~1%, indicating the probable presence of tens of thousands of pythons. Python molurus has the potential to occupy the entire footprint of the CERP, adversely impacting valued resources across the landscape. The results of this project will be applied to develop a comprehensive, science-based control and containment program. Information and methods can also be used in adjacent areas such as Big Cypress National Preserve, South Florida Water Management District lands, and Seminole areas.

Status: Ongoing

Recent Products:

  1. Results of work supported by GE PES were presented by Reed and/or Rodda at the following meetings/venues:
    • Snake Ecology Group V (quadrennial international meeting), Boise ID, July 09 (climate matching for pythons and other invasive reptiles)
    • Congressional briefing on the Reed & Rodda 2009 risk assessment for giant constrictors, Rayburn House Office Bldg, Washington, DC, Oct 09
    • Briefing and discussion on the Reed & Rodda 2009 risk assessment for giant constrictors, National Invasive Species Council, Washington, DC, Oct 09
    • DOI briefing on the Reed & Rodda 2009 risk assessment for giant constrictors, U.S. Department of the Interior, Washington, DC, Sept 09
    • Attendance as Technical Witness for DOI Deputy Director Dan Ashe at House committee hearing on HR2811, Nov 09
    • USFWS Vero Beach Field Office, Vero Beach, FL, August 09 (Update on giant constrictors)
    • DOI python meeting, Davie, FL, Sept 09 (Summary of control tools and research directions for partner agencies)
    • Colorado State University, Dept Fish, Wildlife, and Conservation Biology, April & Sept 09 (seminars on invasive giant constrictors)
    • Python research strategy meeting (multi-agency), West Palm Beach, Jan 08 (Challenges in developing traps for pythons)
    • Wild Aruba conference, Oranjestad, Aruba, August 2008 (Applying python methods to invasive boas)
    • Python strategy meeting (multi-agency), Stuart FL, Dec 08 (Update on trap development)
    • All-Florida Herpetology Conference, Gainesville, Mar 09 (python invasiveness)
  2. GE PES funding allowed Reed and Rodda to travel to FL, meet with cooperators, conduct site visits, and gain information vital to preparation of the following reports:
    • Reed, R.N. and G.H. Rodda. 2009. Giant constrictors: biological and management profiles and an establishment risk assessment for nine large species of pythons, anacondas, and the boa constrictor. US Geological Survey Open-File Report 2009-1202, U.S. Geological Survey, Reston, Virginia, 2009, xviii + 302 pp.
    • Reed, R.N., K.L. Krysko, R.W. Snow, and G.H. Rodda. In review. Evidence for an established population of the Northern African Python (Python sebae) in southern Florida. Submitted to Reptiles and Amphibians: Conservation and Natural History.
    • Reed and/or Rodda also wrote a number of research protocols, summaries of needed research for python control, and similar documents at the request of cooperators/clients (these are available on request; examples include advising FWS of parasites associated with pythons, advising NPS on humane euthanasia methods for reptiles, etc.)
  3. GE PES funding allowed Reed, Rodda, and Hart to act as Principal Investigators for the following major research project:
    • A mainland trap trial for Burmese Pythons in south Florida. Highlights of this recently-completed trial include:
      • Approximately 6,000 trap-nights of sampling effort
      • Capture of 3 Burmese Pythons using baited box traps
      • Very low capture rates of non-target species
      • Post-trapping agricultural treatment of the sampling area to estimate background numbers of pythons, non-target species, and prey species
      • Hiring (through UF) a full-time employee for trap development, with the period of employment extending through much of FY10
      • A full report on this project will be submitted for FSP review by mid-February 2010, after which it will be submitted for journal publication

Planned Products:

  1. Progress (semi-annual) and final (annual) reports.
  2. Datasets provided to funding agency at completion of study.
  3. Additional articles to be submitted for peer review in scientific journals.
  4. A report summarizing the state of knowledge of available means of detecting, capturing, and reducing populations of introduced giant constrictors in the U.S, including relative efficacy of traps vs. alternative control techniques, implications for management of Burmese Pythons as well as other invasive giant constrictors and ESA-listed species, and directions for future development of control tools (to be delivered at the conclusion of this 3-year effort)


Title of Task: Trap Development for Invasive Burmese Pythons
Task Funding: USGS Greater Everglades Priority Ecosystems Science (GE PES)
Task Leaders: Robert N. Reed, Gordon H. Rodda, Kristen Hart
Phone: 970-226-9471
FAX: 970-226-9230
Task Status (proposed or active): Active
Task priority: High
Budget and Time Frame for Task: FY09, FY10, FY11
Task Personnel: Skip Snow (ENP) Ron Rozar, Scott Goetz (USGS), Frank Mazzotti, Michael Cherkiss (UFL), additional seasonal/term employees

Task Summary and Objectives:

Rodda and Reed (PI's) have provided science support and technical assistance to nearly all aspects of research on invasive Burmese Pythons in Florida over the past few years. Our primary cooperators/clients have been NPS, FWS, SFWMD, and U. Florida. Our contributions have spanned trap development, detection tools, risk assessments, snake ecology, and other fields, but this narrative will primarily address trap development. In pursuing this project we have been informed by our experience developing traps for invasive brown treesnakes on Guam, as well as by fieldwork and capture techniques for a wide variety of additional reptile species - as an example, brown treesnake trap capture success increased by roughly two orders of magnitude due to extensive USGS trap trials by Rodda.

In FY08 and FY09, GE PES funding allowed us to pursue several science projects in ENP and environs. We proposed erection of a 10'x10' shed at ENP, in which trap entrance designs could be systematically tested using pythons collected from the field. The shed was erected by cooperators and a limited number of research trials were conducted in FY08. USGS staff have proposed to use this shed to test additional trap designs, including filming the responses of pythons in the shed to variations of prototype metal traps before settling on a final design for deployment. In FY08 we provided technical assistance to cooperators on construction and deployment of python traps in mainland areas, and followed up with a leadership role in the recently-completed trap trial in the Frog Pond area east of Everglades NP. Developing traps for pythons is a relatively new and unproven endeavor that involves a wide variety of cooperators, and the construction, deployment, and checking of large traps requires a lot of labor. We plan to use GE PES funds to construct, deploy, and test additional mainland traps in FY09 and in out-years so as to demonstrate our commitment to amassing a trap-success dataset in occupied habitat.

During FY09, funding from GE PES was vital to allowing Colorado-based PI's to spend time with our Key Largo staff, Davie-based USGS colleagues, and other cooperators and to pay PI salary for time spent writing documents described below, as FWS funding does not include any money for travel. Our project on Key Largo allowed significant progress in the following areas:

  • Development of specifications and schematics for traps
  • Fabrication,deployment, and daily checks of traps (N=59) and 50 m drift fences (N=4)
  • Successful capture of a Burmese Python in one of the Key Largo traps
  • Identification of suitable mainland locations for trap deployment in areas with existing Burmese Python populations, especially along the US-1 corridor and other obvious invasion pathways to Key Largo.
  • Continuation of intensive fieldwork to detect and control an incipient population of pythons on Key Largo using alternative detection methods (visual surveys, road surveys, etc.)
  • Progress on construction of metal-framed and portable python traps
  • Completion of an outreach flyer on pythons, to be mailed to all residents of north Key Largo
  • Collection of data on non-target captures, and devising means to reduce bycatch of non-targets via escape hatches for small species, alternative trap entrance designs, etc.

The main objective of this study for FY09-FY11 is to develop and rigorously test a variety of possible control tools for Burmese Pythons in the greater Everglades ecosystem. As traps are the primary tool used in snake control efforts worldwide, we will focus on developing an effective trap via largescale replicated trap trials in mainland Everglades habitats (see attached sub-proposal for background on trap development and an outline of the first of these proposed trials).

Another goal for FY10 and out-years is to increase the frequency of communication with cooperators. Towards this end, we are excited about the addition of a new USGS PI in south Florida (K. Hart), as this will foster more effective communication with cooperators and better coordination between PI's based in FL and CO. By fostering a more effective partnership, we can more effectively pursue our shared goal of expanding trap testing sample sizes, both on the mainland and in controlled trials in ENP. Meanwhile, we have been learning quite a bit about the operation of python traps via our FWS-funded project on Key Largo, which has as its goal python control in support of ESA-listed rodents. Findings from Key Largo, including means of excluding non-target species and ways to increase trap durability in harsh climates, will be incorporated into all mainland trap development efforts.

Scope of work - Work to be undertaken during each proposal year and a description of the methods and procedures:

The following goals were included in our FY09 GE PES proposal, and we are pleased to have successfully achieved them as described in parenthetical comments:

  • Support the construction and deployment of at least 30 python traps for use in mainland trap testing, to demonstrate our commitment to increasing sample sizes of trap testing trials (60 traps were built and deployed for the mainland trap trial)
  • Initiate a mainland trap trial (~6,000 trap-days; see attached sub-proposal) for invasive pythons in the Frog Pond area, focusing on assessing efficacy of several trap designs (this trial will carry over into the next FY) (This trial recently wrapped up, data currently undergoing QA/QC)
  • Field-test at least three variations on trap designs to assess relative efficacy (Two variations on box traps and one type of collapsible trap were tested)
  • Offer technical assistance and invasive snake expertise to efforts involving the trap-testing shed and 1-ha enclosure (to the extent possible given labor considerations - the field trap trial above will take precedence over other activities) (See above for examples of technical assistance)
  • Interact regularly with Kristen Hart to integrate USGS efforts on invasive species in South Florida and present a USGS consensus on research priorities to cooperators, clients, and policy makers (Interactions with Hart in FY09 were scientifically rewarding)
  • Pursue more detailed and more frequent communication with cooperators from NPS and UFL so as to result in quality science products, including institution of regular conference calls and formal proposals for projects with input from all cooperators (Several conference calls were held as a result of Hart's efforts, and FORT staff led production of proposals, protocols, and data sheets associated with the mainland trap trial. Increasing the frequency of conference calls in FY10 would further improve communications.)
  • Work with cooperators to increase the rate of publication of science products relating to invasive pythons and their impacts on South Florida ecosystems (One major report and one journal article were completed by Reed and Rodda, and we are in discussions with Hart to prepare several additional articles during FY10)
  • Be available to cooperators for consultation, proposal preparation, manuscript review, and other needs related to maintaining high quality scientific guidance for python research and control (We feel that we succeeded in this goal, although few manuscripts were prepared for our review)
  • Spend at least 30 PI-days in Florida (Reed and Rodda spent a total of 32 PI-days in FL in FY09)

Proposed activities for FY10 include the following:

  • Analyze data from first mainland trap trial (see above), complete a full report to funding agencies, submit for journal publication
  • Provide material support for, and participate in, organized search efforts for Northern African Pythons (P. sebae) in west Miami, with the goal of eradicating this possibly-established species before it spreads
  • Apply trap improvements resulting from FY09 trap design developments and controlled testing to deployed traps on mainland and on Key Largo
  • Initiate at least one additional mainland trap trial/trap deployment with collaborators (~8,000 trap-days), sites TBD, with experimental design guided by results of first trap trial
  • Field-test at least two new variations on trap designs to assess relative efficacy, including evaluation of drift fences as a means of increasing capture rates
  • Collaborate with cooperators to produce at least two manuscripts on pythons for submission to peer-reviewed outlets
  • Be available to cooperators for consultation, proposal preparation, manuscript review, and other needs related to maintaining high quality scientific guidance for python research and control
  • Spend at least 30 PI-days in Florida

Proposed activities for FY11 include the following:

  • Complete second mainland trap trial, analysis and publication of results
  • Apply trap improvements resulting from FY09-10 field trials to deployed traps anywhere in the range or suspected range of introduced giant constrictors
  • Deploy and check at least 25 traps in one or more areas of high conservation value (e.g., wood stork rookeries, hardwood hammocks, etc); areas TBD with input from resource protection and management agencies
  • Produce a report summarizing the state of knowledge of available means of detecting, capturing, and reducing populations of introduced giant constrictors in the U.S, including relative efficacy of traps vs. alternative control techniques, implications for management of Burmese Pythons as well as other invasive giant constrictors and ESA-listed species, and directions for future development of control tools
  • Be available to cooperators for consultation, proposal preparation, manuscript review, and other needs related to maintaining high quality scientific guidance for python research and control
  • Collaborate with cooperators to produce at least two manuscripts on pythons for submission to a peer-reviewed journal
  • Spend at least 30 PI-days in Florida

Specific Task Product(s): The main focus of this study will be development and testing of traps and other control tools for invasive Burmese Pythons in the greater Everglades ecosystem and elsewhere. Secondary goals include providing scientific guidance on snake ecology and invasive species control tools, as well as Results will be reported in technical reports, fact sheets, scientific and public presentations and/or peer reviewed publications (see SOW by FY, above, for examples of specific products). The data from this study will be used to plan control efforts for Burmese pythons, and will provide baseline information on population size and structure in the areas where traps and other control tools are tested. Data from this study will also be useful for the development and validation of other detection methods and traps for Burmese Pythons as well as other species of invasive giant constrictors (e.g., Green Anaconda, Yellow Anaconda, Boa Constrictor, etc). A final report on the state of knowledge of python control tools will be produced as part of the FY11 products, as stated above.

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