DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 16
RIN 1018-AV68
[FWS-R9-FHC-2008-0015]
[94140-1342-0000-N3]
Injurious Wildlife Species; Listing the Boa Constrictor, Four Python Species,
and Four Anaconda Species as Injurious Reptiles
AGENCY:
Fish and Wildlife Service, Interior.
ACTION:
Proposed rule; availability of draft environmental assessment and draft economic
analysis.
SUMMARY:
The U.S. Fish and Wildlife Service (Service) proposes to amend its regulations
to add Indian python (Python molurus, including Burmese python Python molurus
bivittatus), reticulated python (Broghammerus reticulatus or Python
reticulatus), Northern African python (Python sebae), Southern African python
(Python natalensis), boa constrictor (Boa constrictor), yellow anaconda
(Eunectes notaeus), DeSchauensee's anaconda (Eunectes deschauenseei), green
anaconda (Eunectes murinus), and Beni anaconda (Eunectes beniensis) to the list
of injurious reptiles. This listing would prohibit the importation of any live
animal, gamete, viable egg, or hybrid of these nine constrictor snakes into the
United States, except as specifically authorized. The best available information
indicates that this action is necessary to protect the interests of humans,
wildlife, and wildlife resources from the purposeful or accidental introduction
and subsequent establishment of these large constrictor snake populations into
ecosystems of the United States. If the proposed rule is made final, live
snakes, gametes, or hybrids of the nine species or their viable eggs could be
imported only by permit for scientific, medical, educational, or zoological
purposes, or without a permit by Federal agencies solely for their own use. The
proposed rule, if made final, would also prohibit any interstate transportation
of live snakes, gametes, viable eggs, or hybrids of the nine species currently
held in the United States. If the proposed rule is made final, interstate
transportation could be authorized for scientific, medical, educational, or
zoological purposes.
DATES:
We will consider comments we receive on or before [insert date 60 days after
date of publication in the Federal Register].
ADDRESSES:
You may submit comments by one of the following methods:
&sbull;Federal eRulemaking Portal: http://www.regulations.gov. Follow the
instructions for submitting comments to Docket No. FWS-R9-FHC-2008-0015.
&sbull;U.S. mail or hand-delivery: Public Comments Processing, Attn: Docket No.
FWS-R9-FHC-2008-0015; Division of Policy and Directives Management; U.S. Fish
and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; Arlington, VA 22203.
We will not accept e-mail or faxes. We will post all comments on
http://www.regulations.gov. This generally means that we will post any personal
information you provide us (see the Public Comments section below for more
information).
FOR FURTHER INFORMATION CONTACT:
Supervisor, South Florida Ecological Services Office, U.S. Fish and Wildlife
Service, 1339 20th Street, Vero Beach, FL 32960-3559; telephone 772-562-3909
ext. 256. If you use a telecommunications device for the deaf (TDD), please call
the Federal Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Previous Federal Action
On June 23, 2006, the Service received a petition from the South Florida Water
Management District (District) requesting that Burmese pythons be considered for
inclusion in the injurious wildlife regulations under the Lacey Act (18 U.S.C.
42). The District is concerned about the number of Burmese pythons found in
Florida, particularly in Everglades National Park and on the District's
widespread property in South Florida.
The Service published a notice of inquiry in the Federal Register (73 FR 5784;
January 31, 2008) soliciting available biological, economic, and other
information and data on the Python, Boa, and Eunectes genera for possible
addition to the list of injurious wildlife under the Lacey Act and provided a
90day public comment period. The Service received 1,528 comments during the
public comment period that closed April 30, 2008. We reviewed all comments
received for substantive issues and information regarding the injurious nature
of species in the Python, Boa, and Eunectes genera. Of the 1,528 comments, 115
provided economic, ecological, and other data responsive to 10 specific
questions in the notice of inquiry. Most individuals submitting comments
responded to the notice of inquiry as though it was a proposed rule to list
constrictor snakes in the Python, Boa, and Eunectes genera as injurious under
the Lacey Act. As a result, most comments expressed either opposition or support
for listing the large constrictor snakes species and did not provide substantive
information. We considered the information provided in the 115 applicable
comments in the preparation of the draft environmental assessment, draft
economic analysis, and this proposed rule.
For the injurious wildlife evaluation in this proposed rule, we considered: (1)
The substantive information that we received during the notice of inquiry, (2)
information from the United States Geological Survey's (USGS) Giant
Constrictors: Biological and Management Profiles and an Establishment Risk
Assessment for Nine Large Species of Pythons, Anacondas, and the Boa Constrictor
(Reed and Rodda 2009), and (3) the latest findings regarding the nine large
constrictor snakes in Florida and the Commonwealth of Puerto Rico. The USGS's
risk assessment (Reed and Rodda 2009) can be viewed at the following web sites:
http://www.regulations.gov under Docket No. FWS-R9-FHC-2008-0015 and
http://www.fort.usgs.gov/Products/Publications/pub_abstract.asp?PubID=226
91. Reed and Rodda (2009) provided the primary biological, management, and risk
information for this proposed rule. The risk assessment was prepared at the
request of the Service and the National Park Service.
Background
Purpose of Listing as Injurious
The purpose of listing the Indian python (Python molurus, including Burmese
python P. molurus bivittatus), reticulated python (Broghammerus reticulatus or
Python reticulatus), Northern African python (Python sebae), Southern African
python (Python natalensis), boa constrictor (Boa constrictor), yellow anaconda
(Eunectes notaeus), DeSchauensee's anaconda (Eunectes deschauenseei), green
anaconda (Eunectes murinus), and Beni anaconda (Eunectes beniensis) (hereafter,
collectively the nine constrictor snakes) as injurious wildlife would be to
prevent the accidental or intentional introduction of and the possible
subsequent establishment of populations of these snakes in the wild in the
United States.
Why the Nine Species Were Selected for Consideration as Injurious Species
The four true giants (with maximum lengths well exceeding 6 m [20 ft]) are the
Indian python, Northern African python, reticulated python, and green anaconda;
they are prevalent in international trade. The boa constrictor is large,
prevalent in international trade, and already established in South Florida. The
Southern African python, yellow anaconda, DeSchauensee's anaconda, and Beni
anaconda exhibit many of the same biological characteristics as the previous
five species that pose a risk of establishment and negative effects in the
United States. The Service is striving to prevent the introduction and
establishment of all nine species into new areas of the United States due to
concerns about the injurious effects of all nine species consistent with 18
U.S.C. 42.
Need for the Proposed Rule
The threat posed by the Indian python (including Burmese python) and other large
constrictor snakes is evident. Thousands of Indian pythons (including Burmese
pythons) are now breeding in the Everglades and threaten many imperiled species
and other wildlife. In addition, other species of large constrictors are or may
be breeding in South Florida, including boa constrictors and Northern African
pythons. Reticulated pythons, yellow anacondas, and green anacondas have also
been reported in the wild in Florida. Indian pythons (including Burmese
pythons), reticulated pythons, African pythons, boa constrictors, and yellow
anacondas have been reported in the wild in Puerto Rico. The Southern African
python, yellow anaconda, DeSchauensee's anaconda, and Beni anaconda exhibit many
of the same biological characteristics as the previous five species that pose a
risk of establishment and negative effects in the United States.
The USGS risk assessment used a method called climate matching to estimate those
areas of the United States exhibiting climates similar to those experienced by
the species in their respective native ranges (Reed and Rodda 2009).
Considerable uncertainties exist about the native range limits of many of the
giant constrictors, and a myriad of factors other than climate can influence
whether a species could establish a population in a particular location. While
we acknowledge this uncertainty, these tools also serve as a useful predictor to
identify vulnerable ecosystems at risk from injurious wildlife prior to the
species actually becoming established (Lodge et al. 2006). Based on climate
alone, many species of large constrictors are likely to be limited to the
warmest areas of the United States, including parts of Florida, extreme south
Texas, Hawaii, and insular territories. For a few species, large areas of the
continental United States appear to have suitable climatic conditions. There is
a high probability that large constrictors would establish populations in the
wild within their respective thermal and precipitation limits due to common
life-history traits that make them successful invaders, such as being habitat
generalists that are tolerant of urbanization and capable of feeding on a wide
range of size-appropriate vertebrates (reptiles, mammals, birds, amphibians, and
fish; Reed and Rodda 2009). While a few of the largest species have been known
to attack humans in their native ranges, such attacks appear to be rare.
Of the nine large constrictor snakes assessed by Reed and Rodda (2009), five
were shown to pose a high risk to the health of the ecosystem, including the
Indian python or Burmese python, Northern African python, Southern African
python, yellow anaconda, and boa constrictor. The remaining four large
constrictorsthe reticulated python, green anaconda, Beni anaconda, and
DeSchauensee's anacondawere shown to pose a medium risk. None of the large
constrictors that were assessed was classified as low risk. As compared to many
other vertebrates, large constrictors pose a relatively high risk for being
injurious. They are highly adaptable to new environments and opportunistic in
expanding their geographic range. Furthermore, since they are a novel, top
predator, they can threaten the stability of native ecosystems by altering the
ecosystem's form, function, and structure.
Most of these nine species are cryptically marked, which makes them difficult to
detect in the field, complicating efforts to identify the range of populations
or deplete populations through visual searching and removal of individuals.
There are currently no tools available that would appear adequate for
eradication of an established population of giant snakes once they have spread
over a large area.
Listing Process
The regulations contained in 50 CFR part 16 implement the Lacey Act (Act; 18
U.S.C. 42) as amended. Under the terms of the Act, the Secretary of the Interior
is authorized to prescribe by regulation those wild mammals, wild birds, fish,
mollusks, crustaceans, amphibians, reptiles, and the offspring or eggs of any of
the foregoing that are injurious to humans, to the interests of agriculture,
horticulture, or forestry, or to the wildlife or wildlife resources of the
United States. The lists of injurious wildlife species are found at 50 CFR
16.1116.15.
We are evaluating each of the nine species of constrictor snakes individually
and will list only those species that we determine to be injurious. If we
determine that any or all of the nine constrictor snakes in this proposed rule
are injurious, then, as with all listed injurious animals, their importation
into, or transportation between, the States, the District of Columbia, the
Commonwealth of Puerto Rico, or any territory or possession of the United States
by any means whatsoever is prohibited, except by permit for zoological,
educational, medical, or scientific purposes (in accordance with permit
regulations at 50 CFR 16.22), or by Federal agencies without a permit solely for
their own use, upon filing a written declaration with the District Director of
Customs and the U.S. Fish and Wildlife Service Inspector at the port of entry.
The rule would not prohibit intrastate transport of the listed constrictor snake
species within States. Any regulations pertaining to the transport or use of
these species within a particular State would continue to be the responsibility
of that State.
The Lacey Act Evaluation Criteria are used as a guide to evaluate whether a
species does or does not qualify as injurious under the Act. The analysis
developed using the criteria serves as a basis for the Service's regulatory
decision regarding injurious wildlife species listings. A species does not have
to be established, currently imported, or present in the wild in the United
States for the Service to list it as injurious. The objective of such a listing
would be to prevent that species' importation and likely establishment in the
wild, thereby preventing injurious effects consistent with 18 U.S.C. 42.
If the data indicate that a species is injurious, a proposed rule will be
developed. The proposed rule provides the public with a period to comment on the
proposed listing and associated documents.
If a determination is made to not finalize the listing, the Service will
publish a notice in the Federal Register explaining why the species is not added
to the list of injurious wildlife. If a determination is made to list a species
as injurious after evaluating the comments received during the proposed rule's
comment period, a final rule would be published. The final rule contains
responses to comments received on the proposed rule, states the final decision,
and provides the justification for that decision. If listed, species determined
to be injurious will be codified in the Code of Federal Regulations.
Introduction Pathways for Large Constrictor Snakes
The primary pathway for the entry of the nine constrictor snakes into the United
States is the commercial trade in pets. The main ports of entry for imports are
Miami, Los Angeles, Baltimore, Dallas-Ft. Worth, Detroit, Chicago, and San
Francisco. From there, many of the live snakes are transported to animal
dealers, who then transport the snakes to pet retailers. Large constrictor
snakes are also bred in the United States and sold within the country.
A typical pathway of a large constrictor snake includes a pet store. Often, a
person will purchase a hatchling snake (0.5 meters (m) [(22 inches (in)]) at a
pet store or reptile show for as little as $35. The hatchling grows rapidly,
even when fed conservatively, so a strong snake-proof enclosure is necessary.
All snakes are adept at escaping, and pythons are especially powerful when it
comes to breaking out of cages. In captivity, they are fed pre-killed mice,
rats, rabbits, and chickens. A tub of fresh water is needed for the snake to
drink and soak in. As the snake grows too big for a tub in its enclosure, the
snake will have to be bathed in a bathtub. Under captive conditions, pythons
will grow very fast. An Indian python, for example, will grow to more than 20
feet long, weigh 200 pounds, live more than 25 years, and must be fed rabbits
and the like.
Owning a giant snake is a difficult, long-term, somewhat expensive
responsibility. For this reason, many snakes are released by their owners into
the wild when they can no longer care for them, and other snakes escape from
inadequate enclosures. This is a common pathway to invading the ecosystem by
large constrictor snakes (Fujisaki et al. 2009).
In aggregate, the trade in giant constrictors is significant. From 1999 to 2008,
more than 1.8 million live constrictor snakes of 12 species were imported into
the United States (U.S. Fish and Wildlife Service 2010). Of all the constrictor
snake species imported into the United States, the selection of nine constrictor
snakes for evaluation as injurious wildlife was based on concern over the giant
size of these particular snakes combined with their quantity in international
trade. The four largest species of snakesIndian python, Northern African python,
reticulated python, and green anacondawere selected, as well as similar and
closely related species, and the boa constrictor. These giant constrictor snakes
constitute a high risk of injuriousness in relation to those taxa with lower
trade volumes, are large in size with maximum lengths exceeding 6 m (20 ft), and
have a high likelihood of establishment in various habitats of the United
States. The Southern African python, yellow anaconda, DeSchauensee's anaconda,
and Beni anaconda exhibit many of the same biological characteristics as the
previous five species that pose a risk of establishment and negative effects in
the United States.
By far the strongest factor influencing the chances of these large constrictors
establishing in the wild is the number of release events and the numbers of
individuals released. With a sufficient number of either unintentional or
intentional release events, these species will establish in ecosystems with
suitable conditions for survival and reproduction. This is likely the case at
Everglades National Park, where the core nonnative Burmese python population in
Florida is now located. Therefore, allowing unregulated importation and
interstate transport of these exotic species will increase the risk of these new
species becoming established through increased opportunities for release. A
second factor that is strongly and consistently associated with the success of
an invasive species' establishment is a history of it successfully establishing
elsewhere outside its native range. For example, in addition to the established
Indian (including Burmese) python population in Florida, we now know that boa
constrictors are established at the Deering Estate at Cutler preserve in South
Florida, and the Northern African python is established west of Miami, Florida,
in the vicinity known as the Bird Drive Basin Recharge Area. A third factor
strongly associated with establishment success is having a good climate or
habitat match between where the species naturally occurs and where it is
introduced. These three factors have all been consistently demonstrated to
increase the chances of establishment by all invasive vertebrate taxa, including
the nine large constrictor snakes in this proposed rule (Bomford 2008).
However, as stated above, a species does not have to be established, currently
imported, or present in the wild in the United States for the Service to list it
as injurious. The objective of such a listing would be to prevent that species'
importation and likely establishment in the wild, thereby preventing injurious
effects consistent with 18 U.S.C. 42.
Public Comments
We are soliciting substantive public comments and supporting data on the draft
environmental assessment, the draft economic analysis, and this proposed rule to
add the Indian (including Burmese) python, reticulated python (Broghammerus
reticulatus or Python reticulatus), Northern African python, Southern African
python, boa constrictor, yellow anaconda, DeSchauensee's anaconda, green
anaconda, and Beni anaconda to the list of injurious wildlife under the Lacey
Act. The draft environmental assessment, the draft economic analysis, the
initial regulatory flexibility analysis, and this proposed rule will be
available on http://www.regulations.gov under Docket No. FWS-R9-FHC-2008-0015.
You may submit your comments and materials concerning this proposed rule by one
of the methods listed in the ADDRESSES section. We will not accept comments sent
by e-mail or fax or to an address not listed in the ADDRESSES section.
We will post your entire commentincluding your personal identifying
informationon http://www.regulations.gov. If your written comments provide
personal identifying information, you may request at the top of your document
that we withhold this information from public review. However, we cannot
guarantee that we will be able to do so.
Comments and materials we receive, as well as supporting documentation we used
in preparing this proposed rule, will be available for public inspection on
http://www.regulations.gov under Docket No. FWS-R9-FHC-2008-0015, or by
appointment, during normal business hours at the South Florida Ecological
Services Office (see FOR FURTHER INFORMATION CONTACT section).
We are soliciting public comments and supporting data to gain additional
information, and we specifically seek comment regarding the Indian python
(Python molurus, including Burmese python P. m. bivittatus), reticulated python
(Broghammerus reticulatus or Python reticulatus), Northern African python
(Python sebae), Southern African python (Python natalensis), boa constrictor
(Boa constrictor), yellow anaconda (Eunectes notaeus), DeSchauensee's anaconda
(Eunectes deschauenseei), green anaconda (Eunectes murinus), and Beni anaconda
(Eunectes beniensis) on the following questions:
(1) What regulations does your State have pertaining to the use,
transport, or production of any of the nine constrictor snakes? What are
relevant Federal, State, or local rules that may duplicate, overlap, or conflict
with the proposed rule?
(2) How many of the nine constrictor snakes species are currently in production
for wholesale or retail sale, and in how many and which States?
(3) How many businesses sell one or more of the nine constrictor snake species?
(4) How many businesses breed one or more of the nine constrictor snake species?
(5) What are the annual sales for each of the nine constrictor snake species?
(6) How many, if any, of the nine constrictor snake species are permitted within
each State?
(7) What would it cost to eradicate individuals or populations of the nine
constrictor snakes, or similar species, if found? What methods are effective?
(8) What are the costs of implementing propagation, recovery, and restoration
programs for native species that are affected by the nine constrictor snake
species, or similar species?
(9) What State threatened or endangered species would be impacted by the
introduction of any of the nine constrictor snake species?
(10) What species have been impacted, and how, by any of the nine constrictor
snake species?
(11) What provisions in the proposed rule should the Service consider with
regard to: (a) The impact of the provision(s) (including any benefits and
costs), if any, and (b) what alternatives, if any, the Service should consider,
as well as the costs and benefits of those alternatives, paying specific
attention to the effect of the rule on small entities?
(12) How could the proposed rule be modified to reduce any costs or burdens for
small entities consistent with the Service's requirements?
(13) Why we should or should not include hybrids of the nine constrictor
species analyzed in this rule, and if the hybrids possess the same biological
characteristics as the parent species.
Species Information
Indian python (Python molurus, including Burmese python P. molurus bivittatus)
Native Range
The species Python molurus ranges widely over southern and southeast Asia (Reed
and Rodda 2009). Reed and Rodda (2009) state that, at times, the species has
been divided into subspecies recognizable primarily by color. The most widely
used common name for the entire species is Indian python, with P. molurus
bivittatus routinely distinguished as the Burmese python. Because the pet trade
is composed almost entirely of P. m. bivittatus, most popular references simply
use Burmese python. However, hereafter, we refer to the species as Indian python
(for the entire species), unless specifically noted as Burmese (to refer to the
subspecies, or where information sources used that name).
The subspecies, Python molurus molurus is listed as endangered in its native
lands under the Endangered Species Act of 1973, as amended (16 U.S.C. 1531, et
seq.) under the common name of Indian python. P. molurus molurus is also listed
by the Convention on International Trade in Threatened and Endangered Species
(CITES) under Appendix I but uses no common name. All other subspecies in the
genus Python are listed in CITES Appendix II. This rule as proposed would list
all members of Python molurus as injurious.
In its native range, the Indian python occurs in virtually every habitat from
lowland tropical rainforest (Indonesia and Southeast Asia) to thorn-scrub desert
(Pakistan) and grasslands (Sumbawa, India) to montane warm temperate forests
(Nepal and China) (Reed and Rodda 2009). This species inhabits an extraordinary
range of climates, including both temperate and tropical, as well as both very
wet and very dry environments (Reed and Rodda 2009).
Biology
The Indian python's life history is fairly representative of large constrictors
because juveniles are relatively small when they hatch, but nevertheless are
independent from birth, grow rapidly, and mature in a few years. Mature males
search for mates, and the females wait for males to find them during the mating
season, then lay eggs to repeat the cycle. Male Indian pythons do not need to
copulate with females for fertilization of viable eggs. Instead, the female
apparently can fertilize her eggs with her own genetic material, though it is
not known how often this occurs in the wild. Several studies of captives
reported viable eggs from females kept for many years in isolation (Reed and
Rodda).
In a sample of eight clutches discovered in southern Florida (one nest and seven
gravid females), the average clutch size was 36 eggs, but pythons have been
known to lay as many as 107 eggs in one clutch. Adult females from recent
captures in Everglades National Park have been found to be carrying more than 85
eggs (Harvey et al. 2008).
The Burmese python (Python molurus bivittatus) is one of the largest snakes in
the world; it reaches lengths of up to 7 m (23 ft) and weights of over 90
kilograms (kg)(almost 200 pounds (lbs)). Hatchlings range in length from 50 to
80 centimeters (cm)(19 to 31 inches (in)) and can more than double in size
within the first year (Harvey et al. 2008). As is true with all snakes, pythons
grow throughout their lives. Reed and Rodda (2009) cite Bowler (1977) for two
records of Burmese pythons living more than 28 years (up to 34 years, 2 months
for one snake that was already an adult when acquired).
Like all of the giant constrictors, Indian pythons are extremely cryptic in
coloration. They are silent hunters that lie in wait along pathways used by
their prey and then ambush them. They blend so well into their surroundings that
observers have released marked snakes for research purposes and lost sight of
them 5 feet away (Roybal, pers. comm. 2010).
With only a few reported exceptions, Indian pythons eat terrestrial vertebrates,
although they eat a wide variety of terrestrial vertebrates (lizards, frogs,
crocodilians, snakes, birds, and mammals). Special attention has been paid to
the large maximum size of prey taken from python stomachs, both in their native
range and nonnative occurrences in the United States. The most well-known large
prey items include alligators, antelopes, dogs, deer, jackals, goats,
porcupines, wild boars, pangolins, bobcats, pea fowl, frigate birds, great blue
herons, langurs, and flying foxes; a leopard has even been reported as prey
(Reed and Rodda 2009). To accommodate the large size of prey, Indian pythons
have the ability to grow stomach tissue quickly to digest a large meal (Reed and
Rodda 2009).
Reticulated Python (Broghammerus reticulatus or Python reticulatus)
Native Range
Although native range boundaries are disputed, reticulated pythons
conservatively range across much of mainland Southeast Asia (Reed and Rodda
2009). They are found from sea level up to more than 1,300 m (4,265 ft) and
inhabit lowland primary and secondary tropical wet forests, tropical open dry
forests, tropical wet montane forests, rocky scrublands, swamps, marshes,
plantations and cultivated areas, and suburban and urban areas. Reticulated
pythons occur primarily in areas with a wet tropical climate. Although they also
occur in areas that are seasonally dry, reticulated pythons do not occur in
areas that are continuously dry or very cold at any time (Reed and Rodda 2009).
Biology
The reticulated python is most likely the world's longest snake (Reed and Rodda
2009). Adults can grow to a length of more than 8.7 m (28.5 ft). Like all
pythons, the reticulated python is oviparous (lays eggs). The clutch sizes range
from 8 to 124, with typical clutches of 20 to 40 eggs. Hatchlings are at least
61 cm (2 ft) in total length (Reed and Rodda 2009). We have no data on life
expectancy in the wild, but several captive specimens have lived for nearly 30
years (Reed and Rodda 2009).
The size range of the prey of reticulated pythons is essentially the same as
that of the Indian python, as far as is known (Reed and Rodda 2009), and has
included chickens, rats, monitor lizards, civet cats, bats, an immature cow,
various primates, deer, goats, cats, dogs, ducks, rabbits, tree shrews,
porcupines, and many species of birds.
A host of internal and external parasites plague wild reticulated pythons
(Auliya 2006). The pythons in general are hosts to various protozoans,
nematodes, ticks, and lung arthropods (Reed and Rodda 2009). Captive reticulated
pythons can carry ticks of agricultural significance (potential threat to
domestic livestock) in Florida (Burridge et al. 2000, 2006; Clark and Doten
1995).
The reticulated python can be an aggressive and dangerous species of giant
constrictor to humans. Reed and Rodda (2009) cite numerous sources of people
being bitten, attacked, and even killed by reticulated pythons in their native
range.
Northern African Python (Python sebae)
Native Range
Python sebae and Python natalensis are closely related, large-bodied pythons of
similar appearance found in sub-Saharan Africa (Reed and Rodda 2009). The most
common English name for this species complex has been African rock python. After
P. sebae was split from P. natalensis, some authors added Northern or Southern
as a prefix to this common name. Reed and Rodda 2009 adopted Broadley's (1999)
recommendations and refer to these snakes as the Northern and Southern African
pythons; hereafter, we refer to them as Northern and Southern African pythons,
or occasionally as African pythons.
Northern African pythons range from the coasts of Kenya and Tanzania across much
of central Africa to Mali and Mauritania, as well as north to Ethiopia and
perhaps Eritrea; in arid zones, their range is apparently limited to the
vicinity of permanent water (Reed and Rodda 2009). In Nigeria, Northern African
pythons are reported from suburban, forest, pond and stream, and swamp habitats,
including extensive use of Nigerian mangrove habitats. In the arid northern
parts of its range, Northern African pythons appear to be limited to wetlands,
including the headwaters of the Nile, isolated wetlands in the Sahel of
Mauritania and Senegal, and the Shabelle and Jubba Rivers of Somalia (Reed and
Rodda 2009). The Northern African python inhabits regions with some of the
highest mean monthly temperatures identified for any of the giant constrictors,
with means of greater than 35 °C (95 °F) in arid northern localities
(Reed and Rodda 2009).
Biology
Northern African pythons are primarily ambush foragers, lying in wait for prey
in burrows, along animal trails, and in water. Northern African pythons are
oviparous. Branch (1988) reports that an average female of 3 to 4 m (10 to 13
ft) total length would be expected to lay 30 to 40 eggs, while others report an
average clutch of 46 eggs, individual clutches from 20 to about 100, and clutch
size increasing correspondingly in relation to the body length of the female
(Pope 1961). In captivity, Northern African pythons have lived for 27 years
(Snider and Bowler 1992). As with most of the giant constrictors, adult African
pythons primarily eat endothermic (warm-blooded) prey from a wide variety of
taxa. Domestic animals consumed by African pythons include goats, dogs, and a
domestic turkey consumed by an individual in suburban South Florida.
Southern African Python (Python natalensis)
Native Range
The Southern African python is found from Kenya southwest to Angola and
south through parts of Namibia and much of eastern South Africa. Distributions
of the species overlap somewhat, although the southern species tends to inhabit
higher areas in regions where both species occur (Reed and Rodda 2009).
Biology
Little is known about Southern African pythons. They are oviparous. As with most
of the giant constrictors, adult African pythons primarily eat endothermic
(warm-blooded) prey from a wide variety of taxa. The Southern African pythons
consume a variety of prey types that includes those listed for Northern African
pythons.
Boa Constrictor (Boa constrictor)
Native Range
Boa constrictors range widely over North America (Mexico), Central America, and
South America, including dozens of marine and lacustrine islands, and have one
of the widest latitudinal distributions of any snake in the world. In their
native range, boa constrictors inhabit environments from sea level to 1,000 m
(3,280 ft), including wet and dry tropical forest, savanna, very dry thorn
scrub, and cultivated fields. They are commonly found in or along rivers and
streams because they are capable swimmers (Reed and Rodda 2009; Snow et al.
2007).
Biology
The maximum length of this species is roughly 4 m (13 ft). Boa constrictors are
ovoviviparous (bear live young after eggs hatch inside mother). The average
clutch size is 35 eggs. Snake longevity records from captive-bred populations
can be 38 to 40 years (Reed and Rodda 2009).
The boa constrictor has a broad diet, consuming prey from a wide variety of
vertebrate taxa. Young boa constrictors will eat mice, small birds, lizards, and
amphibians. The size of the prey item will increase as the snake gets older and
larger. The boa constrictor is an ambush predator and will lie in wait for an
appropriate prey to come along, at which point it will attack (Reed and Rodda
2009; Snow et al. 2007).
The subspecies Boa constrictor occidentalis is listed by CITES under Appendix I
but uses no common name. This rule as proposed would list all subspecies of Boa
constrictor as injurious.
Yellow Anaconda (Eunectes notaeus)
Native Range
The yellow anaconda (E. notaeus) has a larger distribution in subtropical and
temperate areas of South America than the DeSchauensee's anaconda and has
received more scientific attention. The yellow anaconda appears to be restricted
to swampy, seasonally flooded, or riverine habitats throughout its range. The
yellow anaconda exhibits a fairly temperate climate range, including localities
with cold-season monthly mean temperatures around 10 °C (50 °F) and no
localities with monthly means exceeding 30 °C (86 °F) in the warm season
(Reed and Rodda 2009).
Biology
The yellow anaconda bears live young (ovoviviparous). The recorded number of
yellow anaconda offspring range from 10 to 37, with a maximum of 56. In
captivity, yellow anacondas have lived for over 20 years. Yellow anacondas
appear to be generalist predators on a range of vertebrates. The anacondas in
general exhibit among the broadest diet range of any snake, including ectotherms
(lizards, crocodilians, turtles, snakes, fish) and endotherms (birds, mammals),
and yellow anacondas have typical diets.
DeSchauensee's Anaconda (Eunectes deschauenseei)
Native Range
This species has a much smaller range than does the yellow anaconda and is
largely confined to the Brazilian island of Marajo, nearby areas
around the mouth of the Amazon River, and several drainages in French Guiana.
DeSchauensee's anaconda is known from a small number of specimens and has a
limited range in northeast South America. Although not well studied,
DeSchauensee's anaconda apparently prefers swampy habitats that may be
seasonally flooded. DeSchauensee's anaconda is known from only a few localities
in northeast South America, and its known climate range is accordingly very
small. While the occupied range exhibits moderate variation in precipitation
across the year, annual temperatures tend to range between 25 oC (77 oF) and 30
oC (86 oF). Whether the species could tolerate greater climatic variation is
unknown.
Biology
DeSchauensee's anaconda appears to be the smallest of the anacondas, although
the extremely limited number of available specimens does not allow unequivocal
determination of maximal body sizes. Dirksen and Henderson (2002) record a
maximum total length of available specimens as 1.92 m (6.3 (ft)) in males and
3.0 m (9.8 (ft)) in females. The DeSchauensee's anaconda is live-bearing. In
captivity, DeSchauensee's anacondas have been reported to live for 17 years, 11
months (Snider and Bowler 1992). Clutch sizes of DeSchauensee's anacondas ranged
from 3 to 27 (mean 10.6 ± 9.6) in a sample of five museum specimens
(Pizzatto and Marques 2007), a range far greater than reported in some general
works (for example, 3-7 offspring; Walls, 1998).
DeSchauensee's anaconda is reported to consume mammals, fish, and birds, and its
overall diet is assumed to be similar to that of the yellow anaconda (Reed and
Rodda 2009).
Green Anaconda (Eunectes murinus)
Native Range
The native range of green anaconda includes aquatic habitats in much of South
America below 850 m (2,789 ft) elevation plus the insular population on
Trinidad, encompassing the Amazon and Orinoco Basins; major Guianan rivers; the
San Francisco, Parana, and Paraguay Rivers in Brazil; and extending south as far
as the Tropic of Capricorn in northeast Paraguay. The range of green anaconda is
largely defined by availability of aquatic habitats. Depending on location
within the wide distribution of the species, these appear to include deep,
shallow, turbid, and clear waters, and both lacustrine and riverine habitats
(Reed and Rodda 2009).
Biology
Reed and Rodda (2009) describe the green anaconda as truly a giant snake, with
fairly reliable records of lengths over 7 m (23 ft) and having a very stout
body. Very large anacondas are almost certainly the heaviest snakes in the
world, ranging up to 200 kg (441 lbs) (Bisplinghof and Bellosa 2007), even
though reticulated pythons, for example, may attain greater lengths.
The green anaconda bears live young. The maximum recorded litter size is 82,
removed from a Brazilian specimen, but the typical range is 28 to 42 young.
Neonates (newly born young) are around 70 to 80 cm (27.5 to 31.5 in) long and
receive no parental care. Because of their small size, they often fall prey to
other animals. If they survive, they grow rapidly until they reach sexual
maturity in their first few years (Reed and Rodda 2009). While reproduction is
typically sexual, Reed and Rodda (2009) report that a captive, female green
anaconda that was 5 years old in 1976 and that had no access to males gave birth
in 2002 to 23 females. This raises the possibility that green anacondas are
facultatively parthenogenic, and that, theoretically, a single female green
anaconda could establish a population.
The green anaconda is considered a top predator in South American ecosystems.
Small anacondas appear to primarily consume birds, and as they mature, they
undergo an ontogenetic prey shift to large mammals and reptiles. The regular
inclusion of fish in the diet of the anacondas (including other members of the
genus Eunectes) increases their dietary niche breadth in relation to the other
giant constrictors, which rarely consume fish. Green anacondas consume a wide
variety of endotherms and ectotherms from higher taxa, including such large prey
as deer and crocodilians (alligators are a type of crocodilian). The regular
inclusion of fish, turtles, and other aquatic organisms in their diet increases
their range of prey even beyond that of reticulated or Indian pythons. Organisms
that regularly come in contact with aquatic habitats are likely to be most
commonly consumed by green anacondas (Reed and Rodda 2009). Green anacondas
would have a ready food supply anywhere that the climate and habitat matched
their native range. Since green anacondas are known to prey upon crocodilians,
they could potentially thrive on alligators, which are common in the
southeastern United States.
Beni Anaconda (Eunectes beniensis)
Native Range
The Beni anaconda is a recently described and poorly known anaconda closely
related to the green anaconda (Reed and Rodda 2009). The native range of the
Beni anaconda is the Itenez/Guapore River in Bolivia along the border with
Brazil, as well as the Baures River drainage in Bolivia. The green and Beni
anacondas are similar in size and the range of the Beni anaconda is within the
range of the green anaconda (Bolivia).
Biology
Eunectes beniensis is a recently described species from northern Bolivia,
previously considered to be contained within E. murinus. Eunectes beniensis was
discovered in the Beni Province, Boliviathus the labeled name of Beni anaconda
and another alias of Bolivian anaconda. Based on morphological and molecular
genetic evidence, E. beniensis is more closely related to E. notaeus and E.
deschauenseei than to E. murinus. The phylogenetic relationships within Eunectes
are currently best described as: E. murinus [E. beniensis (E. deschauenseei, E.
notaeus)]. To an experienced herpetologist, E. beniensis is easily recognizable
by its brown to olive-brownish ground color in combination with five head
stripes and less than 100 large, dark, solid dorsal blotches that always lack
lighter centers. To a novice, E. beniensis and E. murinus are similar in
appearance. The primarily nocturnal anaconda species tends to spend most of its
life in or around water.
Summary of the Presence of the Nine Constrictor Snakes in the United States
Of the nine constrictor snake species that are proposed for listing as
injurious, six have been reported in the wild in the United States and two have
been confirmed as reproducing in the wild in the United States; six have been
imported commercially into the United States during the period 1999 to 2008
(Table 1).
Table 1. The species of nine snakes proposed for listing as injurious that have
been reported in the United States, are known to be breeding in the United
States, and have been imported for trade.
Species
Reported in the wild in U.S.?
Reproducing in the wild in U.S.?
Imported into U.S. for trade?*
Indian (or Burmese) pythonYesYes
Yes
Reticulated pythonYesNo
Yes
Northern African pythonYesPossible
Yes
Southern African pythonNoNo
Unknown**
Boa constrictorYesYes
Yes
Yellow anacondaYesNo
Yes
DeSchauensee's anacondaNoNo
Unknown**
Green anacondaYesNo
Yes
Beni anacondaNoNo
Unknown**
*Data from Draft Economic Analysis (USFWS 2010)
** It is possible that this species has been imported into the U.S. incorrectly
identified as one of the other species under consideration in this rule.
Lacey Act Evaluation Criteria
We use the criteria below to evaluate whether a species does or does not
qualify as injurious under the Lacey Act, 18 U.S.C. 42. The analysis that is
developed using these criteria serves as a general basis for the Service's
regulatory decision regarding injurious wildlife species listings (not just for
the nine proposed snake species). Biologists within the Service who are
knowledgeable about a species being evaluated will assess both the factors that
contribute to and the factors that reduce the likelihood of injuriousness.
(1) Factors that contribute to being considered injurious:
&sbull;The likelihood of release or escape;
&sbull;Potential to survive, become established, and spread;
&sbull;Impacts on wildlife resources or ecosystems through hybridization and
competition for food and habitats, habitat degradation and destruction,
predation, and pathogen transfer;
&sbull;Impact to threatened and endangered species and their habitats;
&sbull;Impacts to human beings, forestry, horticulture, and agriculture; and
&sbull;Wildlife or habitat damages that may occur from control measures.
(2) Factors that reduce the likelihood of the species being considered as
injurious:
&sbull;Ability to prevent escape and establishment;
&sbull;Potential to eradicate or manage established populations (for example,
making organisms sterile);
&sbull;Ability to rehabilitate disturbed ecosystems;
&sbull;Ability to prevent or control the spread of pathogens or parasites; and
&sbull;Any potential ecological benefits to introduction.
To obtain some of the information for the above criteria, we used Reed and Rodda
(2009). Reed and Rodda (2009) developed the Organism Risk Potential scores for
each species using a widely utilized risk assessment procedure that was
published by the Aquatic Nuisance Species Task Force (ANSTF 1996). This
procedure incorporates four factors associated with probability of establishment
and three factors associated with consequences of establishment, with the
combination of these factors resulting in an overall Organism Risk Potential
(ORP) for each species. For the nine constrictor snakes under consideration, the
risk of establishment ranged from medium (reticulated python, DeSchauensee's
anaconda, green anaconda, and Beni anaconda) to high (Indian python, Northern
African python, Southern African python, boa constrictor, and yellow anaconda).
For the nine constrictor snakes under consideration, the consequences of
establishment range from low (DeSchauensee's anaconda and Beni anaconda) to
medium (reticulated python, yellow anaconda, and green anaconda) to high (Indian
python, Northern African python, Southern African python, and boa constrictor).
The overall ORP, which is derived from an algorithm of both probability of
establishment and consequences of establishment, was found to range from medium
(reticulated python, green anaconda, DeSchauensee's anaconda, and Beni anaconda)
to high (Indian python, Northern African python, Southern African python, boa
constrictor, yellow anaconda).
Certainties were highly variable within each of the seven elements of the risk
assessment, varying from very uncertain to very certain. In general, the highest
certainties were associated with those species unequivocally established in
Florida (Indian python and boa constrictor) because of enhanced ecological
information on these species from studies in both their native range and in
Florida. The way in which these sub-scores are obtained and combined is set
forth in an algorithm created by the ANSTF (Table 2).
Table 2. The algorithm that the ANSTF defined for combining the two primary subscores
(Reed and Rodda 2009)
Probability of
Establishment
Consequences of
Establishment
Organism Risk
Potential (ORP)
HighHigh
High
MediumHigh
High
LowHigh
Medium
HighMedium
High
MediumMedium
Medium
LowMedium
Medium
HighLow
Medium
MediumLow
Medium
LowLow
Low
Similar algorithms are used for deriving the primary sub-scores from the
secondary sub-scores. However, the scores are fundamentally qualitative, in the
sense that there is no unequivocal threshold that is given in advance to
determine when a given risk passes from being low to medium, and so forth.
Therefore, we viewed the process as one of providing relative ranks for each
species. Thus a high ORP score indicates that such a species would likely entail
greater consequences or greater probability of establishment than would a
species whose ORP was medium or low (that is, high > medium > low). Highrisk
species are Indian pythons, Northern and Southern African pythons, boa
constrictors, and yellow anacondas. High-risk species, if established in this
country, put larger portions of the U.S. mainland at risk, constitute a greater
ecological threat, or are more common in trade and commerce. Medium-risk species
were reticulated python, DeSchauensee's anaconda, green anaconda, and Beni
anaconda. These species constitute lesser threats in these areas, but still are
potentially serious threats. Because all nine species share characteristics
associated with greater risks, none was found to be a low risk.
For the purposes of this proposed rule, a hybrid is any progeny from any cross
involving parents of these nine constrictor snake species. Such progeny are
likely to possess the same biological characteristics of the parent species
that, through our analysis, leads us to find that they are injurious to humans
and to wildlife and wildlife resources of the United States.
Factors That Contribute to Injuriousness for Indian Python
Current Nonnative Occurrences
The Indian python has been reported as captured in many areas in Florida (see
Figure 4 in the draft environmental assessment). In South Florida, more than
1,300 live and dead Burmese pythons, including gravid females, have been removed
from in and around Everglades National Park in the last 10 years by authorized
agents, park staff, and park partners, indicating that they are already
established (National Park Service 2010). In the Commonwealth of Puerto Rico,
the Indian python has been collected or reported (eight individuals collected,
including a 3-m (10-ft) albino) from the municipality of Adjuntas, the northern
region of the island (Arecibo), and the eastern region of the island (Humacao)
(Saliva, pers. comm. 2009).
Potential Introduction and Spread
The likelihood of release or escape from captivity of Indian python is high as
evidenced by the releases and effects of those releases in Florida and Puerto
Rico. When Indian pythons escape captivity or are released into the wild, they
have survived and are likely to continue to survive and become established with
or without reproduction. For example, in the past 10 years, more than 1,300
Burmese pythons have been removed from Everglades National Park and vicinity
(National Park Service 2010) alone and others have been captured from other
natural areas on the west side of South Florida, the Florida Keys (Higgins,
pers. comm. 2009), and farther up the peninsula, including Sarasota and Indian
River County (Lowman, pers. comm. 2009; Dangerfield, pers. comm. 2010).
Moreover, released Indian pythons would likely spread to areas of the United
States with a suitable climate. These areas were determined in the risk
assessment (Reed and Rodda 2009) for all nine constrictor snakes by comparing
the type of climate the species inhabited in their native ranges to areas of
similar climate in the United States (climate matching). Due to the wide
rainfall tolerance and extensive semi-temperate range of Indian python, large
areas of the southern United States mainland appear to have a climate suitable
for survival of this species. Areas of the United States that are climatically
matched at present include along the coasts and across the south from Delaware
to Oregon, as well as most of California, Texas, Oklahoma, Arkansas, Louisiana,
Mississippi, Alabama, Florida, Georgia, and South and North Carolina. In
addition to these areas of the U.S. mainland, the territories of Guam, Northern
Mariana Islands, American Samoa, Virgin Islands, and Puerto Rico appear to have
suitable climate. Areas of the State of Hawaii with elevations under about 2,500
m (8,202 ft) would also appear to be climatically suitable. Indian pythons are
highly likely to spread and become established in the wild due to common traits
shared by the giant constrictors, including large size, habitat generalist,
tolerance of urbanization, high reproductive potential, long distance disperser,
early maturation, rapid growth, longevity, and sit and wait style of predation.
Potential Impacts to Native Species (including Threatened and Endangered
Species)
As discussed above under Biology, the Indian python grows to lengths greater
than 7 m (23 ft) and can weigh up to 90 kg (200 lbs). This is longer than any
native terrestrial predator (including bears) in the United States and its
territories and heavier than most native predators (including many bears).
American black bears (Ursus americanus) vary in size depending on sex, food
availability and quality, and other factors. Male black bears can grow to more
than six feet long and weigh up to 295 kg (650 lbs); females rarely reach that
length and do not weigh more than 79 kg (175 lbs) (Smithsonian Institution
2010). Among the largest of the native predators of the Southeast is the
American alligator (Alligator mississippiensis). The average length for an adult
female American alligator is 2.6 m (8.2 ft), and the average length for a male
is 3.4 m (11.2 ft) (Smithsonian Institution 2010).
In comparison with the Indian python, the largest snake native to North America
is the indigo snake (Drymarchon corais), attaining a size of about 2.5 m (8 ft)
(Monroe and Monroe 1968). A subspecies of the indigo snake is the eastern indigo
snake (D. corais couperi), which grows to a similar maximum length. The eastern
indigo snake inhabits Georgia and Florida and is listed as federally threatened
by the Service.
Unlike prey species in the Indian python's native range, none of our native
species has evolved defenses to avoid predation by such a large snake. Thus,
naive native wildlife anywhere in the United States would be very
likely to fall prey to Indian pythons (or any of the other eight constrictor
snakes). At all life stages, Indian pythons can and will compete for food with
native species; in other words, baby pythons will eat small prey, and the size
of their prey will increase as they grow. Based on an analysis of their diets in
Florida, Indian pythons, once introduced and established, are likely to
outcompete native predators (such as the federally listed Florida panther,
eastern indigo snake, native boas, hawks), feeding on the same prey and thereby
reducing the supply of prey for the native predators. Indian pythons are
generalist predators that consume a wide variety of mammal and bird species, as
well as reptiles, amphibians, and occasionally fish. This constrictor can easily
adapt to prey on novel wildlife (species that they are not familiar with), and
they need no special adaptations to capture and consume them. Pythons in Florida
have consumed prey as large as white-tailed deer and adult American alligators.
Three federally endangered Key Largo woodrats (Neotoma floridana smalli) were
consumed by a Burmese python in the Florida Keys in 2007. The extremely small
number of remaining Key Largo woodrats suggests that the current status of the
species is precarious (USFWS 2008); this means that a new predator that has been
confirmed to prey on the endangered woodrats is a serious threat to the
continued existence of the species.
The United States, particularly the Southeast, has one of the most diverse
faunal communities that are potentially vulnerable to predation by the Indian
python. Juveniles of these giant constrictors will climb to remove prey from
bird nests and capture perching or sleeping birds. Most of the South has
suitable climate and habitat for Indian pythons. The greatest biological impact
of an introduced predator, such as the Indian python, is the likely loss of
imperiled native species. Based on the food habits and habitat preferences of
the Indian python in its native range, the species is likely to invade the
habitat, prey on, and further threaten most of the federally threatened or
endangered fauna in climate-suitable areas of the United States. Indian pythons
are also likely to threaten numerous other potential candidates for Federal
protection. Candidate species are plants and animals for which the Service has
sufficient information on their biological status and threats to propose them as
endangered or threatened under the Endangered Species Act, but for which
development of a proposed listing regulation is precluded by other higher
priority listing activities. For example, the current candidate list includes
several bat species that inhabit the Indian python's climate-matched regions.
The draft environmental assessment includes lists of species that are federally
threatened or endangered in climate-suitable States and territories, such as
Florida, Hawaii, Guam, Puerto Rico, and the Virgin Islands. These lists include
only the species of the sizes and types that would be expected to be directly
affected by predation by Indian pythons and the other eight large constrictors.
For example, plants and marine species are excluded. In Florida, 14 bird
species, 15 mammals, and 2 reptiles that are threatened or endangered could be
preyed upon by Indian pythons or be outcompeted by them for prey. Hawaii has 32
bird species and one mammal that are threatened or endangered that would be at
risk of predation. Puerto Rico has eight bird species and eight reptile species
that are threatened or endangered that would be at risk of predation. The Virgin
Islands have one bird species and three reptiles that are threatened or
endangered that would be at risk of predation. Guam has six bird species and two
mammals that are threatened or endangered that would be at risk of predation.
According to the climate suitability maps (Reed and Rodda 2009), threatened and
endangered species from all of Florida, most of Hawaii, and all of Puerto Rico
would be at risk from the establishment of Indian pythons. While we did not
itemize the federally threatened and endangered species from California, Texas,
and other States, there are likely several hundred species in those and other
States that would be at risk from Indian pythons. In addition, we assume that
Guam, the U.S. Virgin Islands, and other territories would have suitable habitat
and climate to support Indian pythons, and these also have federally threatened
and endangered species that would be at risk if Indian pythons became
established.
The likelihood and magnitude of the effect on threatened and endangered species
is high. Indian pythons are thus highly likely to negatively affect threatened
and endangered birds and mammals, as well as unlisted native species.
Potential Impacts to Humans
The introduction or establishment of Indian pythons may have negative impacts on
humans primarily from the loss of native wildlife biodiversity, as discussed
above. These losses would affect the aesthetic, recreational, and economic
values currently provided by native wildlife and healthy ecosystems. Educational
values would also be diminished through the loss of biodiversity and ecosystem
health.
Human fatalities from nonvenomous snakes in the wild are rare, probably only a
few per year worldwide (Reed and Rodda 2009). However, although attacks on
people by Indian pythons are improbable, they are possible given the large size
that some individual snakes can reach.
Factors That Reduce or Remove Injuriousness for Indian Python
Control
No effective tools are currently available to detect and remove established
large constrictor populations. Traps with drift fences or barriers are the best
option, but their use on a large scale is prohibitively expensive, largely
because of the labor cost of baiting, checking, and maintaining the traps daily.
Additionally, some areas cannot be effectively trapped due to the expanse of the
area and type of terrain, the distribution of the target species, and the
effects on any nontarget species. While the Department of the Interior, the U.S.
Department of Agriculture's (USDA) Animal and Plant Health Inspection Service
(APHIS), and State of Florida entities have conducted limited research on
control tools, there are currently no such tools available that would appear
adequate for eradication of an established population of large constrictor
snakes, such as the Indian python, once they have spread over a large area.
Efforts to eradicate the Indian python in Florida have become increasingly
intense as the species is reported in new locations across the State. Natural
resource management agencies are expending already-scarce resources to devise
methods to capture or otherwise control any large constrictor snake species.
These agencies recognize that control of large constrictor snakes (as major
predators) on lands that they manage is necessary to prevent the likely adverse
impacts to the ecosystems occupied by the invasive snakes.
The draft economic analysis for the nine constrictor snakes (USFWS January
2010), provides the following information about the expenditures for research
and eradication in Florida, primarily for Indian pythons, which provides some
indication of the efforts to date. The Service spent about $600,000 over a 3year
period (2007 to 2009) on python trap design, deployment, and education in the
Florida Keys to prevent the potential extinction of the endangered Key Largo
woodrat at Crocodile Lake National Wildlife Refuge. The South Florida Water
Management District spent $334,000 between 2005 and 2009 and anticipates
spending an additional $156,600 on research, salaries, and vehicles in the next
several years. An additional $300,000 will go for the assistance of USDA,
Wildlife Services (part of USDA Animal and Plant Health Inspection Service). The
USDA Wildlife Research Center (Gainesville FL Field Station) has spent $15,800
from 2008 to 2009 on salaries, travel, and supplies. The USGS, in con
