The U.S. Fish & Wildlife Service began an Injurious Wildlife Species Review Regarding Python, Boa and Eunectes Species Of Snakes in early 2008. A Notice of Inquiry was published inviting public comment. NEHS submitted the following letter in response to that inquiry:

Public Comments Processing April 13, 2008
ATTN: RIN 1018-AV68
Division of Policy and Directives Management
U.S. Fish & Wildlife Service
4401 North Fairfax Drive, Suite 222
Arlington, VA 22203

RE: Injurious Wildlife Species Review Regarding Python, Boa and Eunectes Species Of Snakes.

Dear, Sir/Madam,

The New England Herpetological Society, hereafter referred to as NEHS, has produced this position paper in response to the proposed listing of the genus’ Python, Boa and Eunectes as “Injurious Wildlife Species” under the Lacey Act.

The NEHS has been in existence for 36 years and was known at its inception as the Massachusetts Herpetological Society. The NEHS has had a long and mutually beneficial relationship with the Massachusetts Division of Fisheries & Wildlife, both in the areas of conservation management and in the implementation and promulgation of exotic species laws pertaining to the keeping of reptiles and amphibians.

The U.S. Fish & Wildlife Service, hereafter referred to as USFWS, has requested answers for a number of questions pertaining to the gathering of data to be used in the review of this proposed regulation. The NEHS will attempt to answer these questions for the USFWS’ benefit as accurately as possible, in the order in which they are presented.

  1. What regulations does your State have pertaining to the use, transport, or production of Python, Boa and Eunectes genera?

    The Commonwealth of Massachusetts has regulations pertaining to the use and production of reptiles and amphibians. Chapter 131, sections 23, 24, 25 and 47 detail the propagator permit system necessary for the breeding and selling of reptiles and amphibians (MGL. 131 pp. 1-3 copies enclosed). There exists an exemption list that is periodically updated to reflect changes in captive breeding status (wild-caught vs. captive bred stock). In the Boinae family, Emerald tree boas Corallus caninus and all anaconda species (Eunectes) are the only boids specifically restricted. In the Pythoninae, African rock pythons python sebae, reticulated pythons python reticulatis and Green tree pythons Morelia viridis are all specifically restricted (Dr. Thomas French, Assistant Dir., Ma. Division of Fisheries & Wildlife pers. comm.). If one were to undertake the business of breeding for sale members of these genera, a propagator’s permit would be required. This permit is not necessary for those who breed species of reptiles or amphibians as a hobby. In addition, the Commonwealth of Massachusetts also restricts the keeping of any federal endangered or threatened species.

  2. How many species in the Python, Boa and Eunectes genera are currently in production for wholesale or retail sale, and in how many and which states?”

    Pythons, boas and anacondas are contained in the family Boidae, which comprises five subfamilies, 23 genera and 79 species distributed throughout the tropics. We will discuss the subfamily Pythoninae (pythons) first.

    This subfamily contains six genera and 22 species found in tropical Africa, Asia and Australia. Of the 22 species, all of them are captive bred in numbers by commercial breeders. Some members of this family are sold for enormous amounts of money. The Google internet search engine is used here for pricing and availability of animals. This search engine turns up Boelen’s Pythons python boeleni selling for $10,000.00 for a captive bred, sexual pair. Aspidites, a genus of two members, the woma and the black headed python are highly regarded and sought after serpents. These animals sell for $2000.00 to $3000.00 a pair. All of the Liasis genus of Australia, New Guinea and Indonesia are also highly sought after and widely captive bred due to Australia’s prohibitive export laws.

    The Burmese or Indian Python, Python molurus was widely captive bred in the late 1980’s and early 1990’s. Tens of thousands of these snakes were captive bred in the U.S. during this time. These pythons are still occasionally offered for sale as hatchlings in large chain pet stores. An amelanistic, or albino color variety of this animal was extremely popular during this time.

    Royal or Ball pythons Python regius, are possibly the most sought after captive bred serpents in the last ten years. Selective breeding has produced an amazing variety of genetic color mutations including but not limited to, albinos, axanthics, cinnamons, clown patterned, enchis, fires, ghost phase, ivories, platinum, Mojave pattern, lemon pastel, piebalds, pinstripes, spider pattern, vanilla and others. There are many commercial breeders who make their primary living from breeding color morphs of this snake alone. Some of these morphs sell for up to $7500.00 per snake. New England Reptile Distributors, a well-known and well-respected commercial establishment in New Hampshire is one excellent example. A quick Google search using the terms “ball python breeders” turns up many commercial breeders for this snake.

    The subfamily Boinae (true boas) contains 11 genera and 41 species found mainly in the New World but also in Madagascar, New Guinea and some pacific islands. Of the 41 species, only the Epicrates genus has 4 species that are not currently captive bred in numbers by commercial breeders. True redtail boa constrictors Boa constrictor, have beautiful colors ranging from light blue to deep purple and red and many color and pattern mutations have made this snake even more popular with commercial breeders and hobbyists than ever before.

    The genus Eunectes comprises only two species, the green anaconda Eunectes murinus and the much smaller yellow anaconda Eunectes notaeus. An internet search reveals hobbyist pricing in the $150.00 to $300.00 range for imported babies and captive bred. Both species require specialized care that not many hobbyists are capable of. Demand for these species appears to be minimal.

    Information on how many species in production in different states is more difficult to assess. In the Commonwealth of Massachusetts, there are no commercial reptile breeding facilities. There are however, pet shops that breed boas and pythons for retail sale and make considerable amounts of money doing so. Pet shops that invest the time and money to breed their own reptile stock avoid many of the pitfalls of buying and shipping their reptiles. They are able to sell a healthier, better quality animal and to charge more money for it. There are also hundreds of hobbyist boa breeders who make significant amounts of extra money from the sale of their captive bred offspring.

  3. How many businesses sell Boa, Python or Eunectes species?

    Petco pet stores, a large, retail chain boasts over 850 stores in the continental U.S. Petsmart pet stores, another large retail chain lists 18 stores in Massachusetts and over 450 retail stores in the continental U.S. Both of these stores routinely sell ball pythons, Python regius and common boa constrictors Boa constrictor. There are also a number of smaller, privately owned pet stores and private hobbyists in Massachusetts that sell captive bred boa constrictors or ball pythons as well as other reptile species.

  4. How many businesses breed Python, Boa and Eunectes species?

    In the Commonwealth of Massachusetts, there are no known businesses breeding Python, Boa or Eunectes species. Again, a Google internet search for “Python breeders,” “Boa breeders” or “Anaconda breeders” will turn up numerous private individuals and businesses nationwide who specialize in these snakes and, as mentioned earlier, command a great deal of money for their offspring. To actually count these businesses would prove problematic. A reasonable estimate would be two or three thousand businesses participating in the captive breeding of Boids nationwide.

  5. What are the annual sales for Python, Boa and Eunectes species?

    This figure would be impossible for the NEHS to determine without access to other data such as income tax filings and bookkeeping records for the many commercial reptile breeders in the U.S. Hobbyists who may not be filing income tax records for the sales of their captive bred offspring must also be taken into account. A reasonable estimate based on information within this report would be at least two million dollars and may be upwards of six or eight million annually when sales of rarely kept and valuable animals are included, as well as the equipment and housing needed to properly care for them. International sales of these animals are significant since the great majority of breeders of Boidae are in the U.S. and demand for captive-bred offspring abroad is great.

  6. Please provide the number of Python, Boa or Eunectes species, if any, permitted within each state?

    Listed below are the species of boas, pythons and anacondas that are explicitly named in MDFW regulations that may only be kept with a permit for some legitimate purpose such as research or educational use. The numbers represent the total number of individuals permitted, followed by the number of permits that allow the possession of that species. These numbers are for the Commonwealth of Massachusetts only.

    Reticulated python Python reticulatus – 10 snakes, 6 permits
    African rock python Python sebae – 5, 3
    Indian python Python molurus- 2, 1
    Green tree python Morelia viridis – 55,5
    Emerald tree boa Corallus caninus- 5,3
    Green anaconda Eunectes murinus – 5,3
    Yellow anaconda Eunectes notaeus– 4,2

    (pers. comm. Dr. Thomas French, Assistant Director, Massachusetts Division of Fisheries & Wildlife)

  7. What would it cost to eradicate Python, Boa or Eunectes individuals or populations, or similar species, if found?

    In Massachusetts, the snake families in question would be eradicated by the sub-optimal temperatures that occupy this state for seven months of every year. Wild populations of these animals would be unable to establish themselves here.

    Florida’s subtropical and tropical climates would present a different situation. Members of these snake families are among the planet’s largest and most efficient predators. As exotic species, they would be the largest snakes existing in the state of Florida. Keeping this in mind, the NEHS has devised a trapping method used by it’s members that has been very successful in retrieving the occasional lost serpent in a home collection, or to collect snakes in the wild in numbers. The method is outlined here as follows:

    Equipment needed:

    1. Lengths of one or two inch diameter pipe, sharpened at one end and preferably taller than the sawgrass in Everglades National Park.

    2. Brightly colored flags of red or yellow.

    3. A sledge hammer.

    4. Clothesline cut into twenty five foot lengths.

    5. A ready supply of large (10-20lb) mammal, (nutira would be ideal) prekilled.

      The unsharpened end of pipe is fitted securely with an end of the clothesline length. The pipe is then pounded into the ground in the swamp or shoreline or anywhere else where snakes have been sighted. The free end of the clothesline is baited with the prekilled mammal by tying the line to its tail or around the neck or in another suitable manner. The top end of the pipe gets a colored flag, one color for a freshly set trap and the other color for a checked and re-baited trap. Other records may be kept and this is an area open for further experimentation. Flags of different colors lend themselves to inspection with binoculars.

      These traps are based on the proven fact that snakes of all species will not disgorge a swallowed prey item deliberately. A snake caught by one of these traps does not realize it is tethered and will remain caught until the trap is checked. Animals trapped may then be destroyed on site. The traps have an additional advantage in that they will not catch any other native snake or other wildlife native to Florida. Alligators may swallow a ten-pound mammal whole, but are more likely to rip it apart. If an alligator manages to get caught, the clothesline may be cut close to the mouth and will pass through the animal’s digestive tract without harm.

      These traps are inexpensive and may be purchased for less than fifteen dollars each if a supply of mammals can be obtained for free. These traps will catch all large constricting snakes that consume warm-blooded mammals. For Eunectes species, these traps may be baited with live or pre-killed carp instead of mammals. These traps may be set by the hundreds in suitable areas and should be checked once or twice per week to dispatch captured snakes or re-bait empty traps.

  8. What are the costs of implementing propagation, recovery and restoration programs for native species that are affected by Boa, Python or Eunectes species, or similar snake species?

    From the standpoint of a northern state, with a northern temperate climate, this question does not apply to Massachusetts. Members of these snake families would be unable to negatively impact any species in this state.

    Florida, with its subtropical and tropical climates would have different issues. However as members of a hobbyist society, our members cannot examine this subject with any authority, not knowing which of Florida’s wildlife may be impacted and in what ways.

  9. What state-listed species would be impacted by the introduction of Python, Boa or Eunectes species?

    This question is not applicable to the Commonwealth of Massachusetts.

    After careful review of available information, the NEHS can surmise that the Florida panther Puma concolor coryi may be at risk of predation by large, exotic constricting snakes. The Florida panther is an apex predator with no known predators of its own. A large exotic python of appropriate size would not hesitate to kill and eat a one hundred pound panther. Large pythons that appear suddenly on Florida’s landscape may present a problem for the panther, which has not developed an evolutionary ability to cope with a highly specialized predator. This situation would be similar to a documented instance of housecats extirpating songbirds in an English neighborhood in the late 1980’s [PB Churcher & JH Lawton, 1987, Predation by domestic cats in an English (UK) village. Journal of Zoology. (London). 212:439-455.]. It must be noted here that to our knowledge and the knowledge of the Florida Fish & Wildlife Conservation Commission, Florida panthers have not been impacted by introduced exotic snakes as of this writing.

  10. What species have been impacted, and how, by Python, Boa and Eunectes species?

    Judging from available information, the American alligator Alligator mississippiensis has been negatively impacted by exotic constricting snakes. It would appear that the American alligator occasionally makes a meal of an exotic snake and vice versa. Based on available data, the NEHS would hypothesize that large American alligators would serve to control large exotic snakes even though available information shows that they at times will become prey themselves.


After careful review it has been determined by the NEHS that the State of Florida has a very real problem with large, exotic constricting snakes. The available and overwhelming information cannot and should not be overlooked.

The NEHS also respectfully asserts that the petition submitted by the South Florida Water Management District to the USFWS was misdirected and should instead have been presented to the Florida Fish & Wildlife Conservation Commission for review.

Interestingly enough, none of the ten questions the USFWS asks in its Injurious Wildlife Species Review pertain to the biology/physiology of the animals in question. Eunectes species are tropical animals and cannot survive and thrive without a minimum ambient temperature of at least 74 degrees Fahrenheit. Prolonged temperatures below this range result in a failure to thrive, digest food and avoid predation. Members of the Boinae family are also tropical animals found in the same region, with very similar requirements and similar results if they are not met.

The family Pythoninae are almost exclusively tropical or desert dwelling species, requiring high relative humidity or none at all and constant minimum temperatures in the mid 70’s Fahrenheit in order to survive and thrive. Burmese pythons, probably the most climatically adaptable of the species, cannot survive several weeks at sub 60 degrees Fahrenheit and are not evolutionarily adapted to survive any length of time at temperatures under 50 degrees Fahrenheit.

The USGS report of potential Burmese python colonization widely circulated in the media is only loosely based on very general climatic conditions on two separate continents, without regard for much broader and more severe temperature and humidity ranges here in the U.S. Periods of freezing weather occur in all 48 continental states for at least a short time every year. This fact alone limits the distribution and range expansion of any tropical reptile in temperate zones. After having spent almost ten fruitless years in Guam trying to turn the tide on the Brown tree snake Boiga irregularis invasion, the alarmist attitude of Gordon Rodda toward exotic snakes is not surprising.

Florida’s subtropical climate is the sole contributing factor in the successful feral introductions of python, boa and anaconda species. The irresponsibility of a small segment of the reptile-keeping public also cannot be overlooked. As noted earlier, an escaped or liberated example of these species would not survive cooler seasonal temperatures in most other states in the continental U.S. and would therefore not present a damaging ecological problem to the local environment.

The NEHS asserts that the problem of non-indigenous exotic snakes establishing themselves in the wild is a problem of south Florida alone, and that the negative economic impact of restriction, prohibition and regulation of these snakes would be significant. The State of Florida boasts the largest number of reptile dealers, breeders and revenue-generating reptile expos of any state in the nation by far. Stricter regulations on ownership may indeed need to be examined, but federal legislation banning or restricting interstate trade in these snakes is not the answer.

Respectfully Submitted,

Ken Smith, President NEHS
Newton, Massachusetts 02465
United States of America
Kurt Schatzl, Vice-President
Braintree, Massachusetts 02184
United States of America
Dawn McCall, Secretary
Shirley, Massachusetts 01464
United States of America
Bill Donovan, Treasurer
Somerville, Massachusetts 02143
United States of America

The New England Herpetological Society
500 Columbian Street
South Weymouth, Massachusetts 02190