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Project Work Plan

Department of Interior USGS GE PES

Fiscal Year 2009 Study Work Plan

Study Title: Control tool development for invasive Burmese Pythons in the Everglades ecosystem
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) (FY09)
Other Complementary Funding Source(s): Interdiction and control of invasive Burmese Pythons on Key Largo USFWS-ES (FY09)
Funding History: GE PES FY07-FY08
Principal Investigator(s): Robert N. Reed, Gordon H. Rodda, Kristen Hart
Project Personnel: Skip Snow (ENP), Ron Rozar (USGS), Frank Mazzotti, Michael Cherkiss (UFL), additional seasonal/term employees
Supporting Organizations: National Park Service - Everglades National Park, University of Florida, 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:

Results of work supported by GE PES were presented by Reed and/or Rodda at the following meetings:

  • 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)
  • 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)
  • Funding from GE PES also allowed Reed and Rodda to travel to FL and gain information that was vital during preparation of a large (~485 pp) risk assessment of multiple species of giant constrictors as potential invasive species in the United States (report is currently being reviewed).

Planned Products:

  1. Progress (semi-annual) and final (annual) reports.
  2. Datasets provided to funding agency at completion of study.
  3. Journal 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 (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, 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. We anticipate that sample sizes will increase now that the bugs have been worked out of this novel experimental arena, and we have plans for some specific trials in the shed. For example, we received funding from FWS to produce prototype metal traps in FY09 and we intend to film the responses of pythons in the shed to variations of these prototypes before settling on a final design for deployment. In FY08 we also provided technical assistance to cooperators on construction and deployment of python traps in mainland areas; we consider this a high priority, but progress towards this goal has been limited. 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 are also limited by availability of snakes for research trials; unlike brown treesnakes on Guam, which can be collected in decent numbers virtually any night of the year, collecting pythons in Florida is highly seasonal, and there are a number of competitors for collected snakes (for necropsies, for radiotelemetry work, for USDA experiments in Gainesville, etc). 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. Finally, NPS and UFL personnel have recently constructed a 1-ha enclosure at ENP to hold a number of pythons, and this enclosure is intended as a semi-natural habitat for additional trap trials and other aspects of python biology and control. We intend to actively participate in the design of these trials.

During FY08, funding from GE PES was vital to allowing Colorado-based PI's to spend time with our Key Largo staff 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 and deployment of traps (N=59) and 50 m drift fences (N=4)
  • 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.
  • Initiation of intensive fieldwork to detect and control an incipient population of pythons on Key Largo using alternative detection methods (visual surveys, road surveys, etc.)
  • 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 FY09 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.

Our specific FY09 goals include the following:

  • 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
  • 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)
  • Field-test at least three variations on trap designs to assess relative efficacy
  • 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).
  • 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
  • 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
  • Work with cooperators to increase the rate of publication of science products relating to invasive pythons and their impacts on South Florida ecosystems
  • 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

Our plans for out-years include the following:


  • Complete first mainland trap trial (see above), as well as analysis and completion of a report to funding agencies
  • Apply trap improvements resulting from FY09 trap design developments and controlled testing to deployed traps on mainland and on Key Largo
  • Initiate a second mainland trap trial with collaborators (~10,000 trap-days), site TBD, with experimental design guided by results of first trap trial
  • Field-test at least three new variations on trap designs to assess relative efficacy
  • Collaborate with cooperators to produce at least one manuscript on pythons for submission to a peer-reviewed journal
  • 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 35 PI-days in Florida


  • 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
  • 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 35 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 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).

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