H.R. 511 Prohibit Importation of Various Injurious Species of Constrictor Snakes

Statement For the Record




November 29, 2012

The U.S. Fish and Wildlife Service (Service) appreciates this opportunity to submit a statement for the record on H.R. 511, a bill to prohibit the importation of several species of constrictor snakes. In general, the bill amends the injurious wildlife provisions of the Lacey Act at 18 U.S.C. 42(a) to add nine species of non-native, constrictor snakes to the list of “injurious wildlife” regulated under this title. With this designation, the importation and interstate transport of these snake species would be prohibited without a permit from the Department of the Interior. H.R. 511 was introduced on January 26, 2012, and referred to the House Judiciary Committee, which reported it with an amendment on February 28, 2012.  The Service supports the bill as introduced, but cannot support the bill as amended by the House Judiciary Committee.


The Lacey Act is among the nation’s oldest and most effective conservation laws. It has proven to be a powerful tool for the conservation of sustainable, native wildlife populations from overharvest and from threats posed by invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

Learn more about invasive species
. Along with a core of other key statutes, like the Plant Protection Act, the injurious wildlife prohibitions in title 18 of the United States Code protect domestic interests against the spread of invasive species, including foreign invasive species known to occupy habitats in the United States that are similar to those in which they live in their home ranges and that could outcompete or prey upon native fish and wildlife, cause damages to our economic interests, or cause or carry disease.

In 2008, the Service published a notice of inquiry in the Federal Register, soliciting available biological, economic, and other information and data on the Python, Boa and Eunectes genera of constrictor snakes for possible addition to the list of “injurious wildlife.”  This notice of inquiry was prompted by a petition from the South Florida Water Management District to the Service requesting the addition of Burmese pythons to this list.

Subsequently, the U.S. Geological Survey (USGS) published a peer-reviewed report, Giant constrictors: Biological and management profiles and an establishment risk assessment for nine large species of Pythons, Anacondas, and the Boa Constrictor, which identified the nine constrictor snake species included in H.R. 511 as posing a risk of becoming established in the United States.  In 2010, the Service published a proposed rule to list all nine species. In

2011, USGS published a clarification on the modeling used for the 2009 report. Finally, in January 2012 the Service published a final rule to list four of the nine species, including Python molurus (which includes Burmese python Python molurus bivittatus and Indian python Python molurus molurus), Northern African python Python sebae, Southern African python Python natalensis, and yellow anaconda Eunectes notaeus on the list of injurious reptiles.

The immediate listing of these four species was found to be warranted because all determined to have a “high risk” for establishment in the wild and for causing damaging impacts to wildlife resources.  The final rule became effective on March 23, 2012. The Service continues review of the remaining five species of constrictor snakes that were included in the 2010 proposed rule but that have not been listed to date.

H.R. 511 Judiciary Committee Amendment

In its amendment to H.R. 511, the House Judiciary Committee retained language in the original bill text adding all nine species to the list of “injurious wildlife” in 18 U.S.C. 42(a), but changed the text of the underlying statute in a way that would considerably alter the liability standard for violations of certain prohibited acts in this statute that are Class B misdemeanor offenses.  The amendment also exempts from the prohibitions in 18 U.S.C. 42(a) the importation and interstate transport of all nine species of large constrictor snakes by state fish and wildlife agencies or “exhibitors,” as defined in section 80.1 of title 50, Code of Federal Regulations.

Under the current statute, prosecution of violations occurs through a “strict liability” standard, meaning it may be based on evidence of the violation without establishing proof of the violator’s intent or prior knowledge about the law or the presence of the injurious species in a given imported or transported shipment. The amendment changes this standard to an intent-based standard with respect to the importation of all injurious animals and plants, meaning prosecution must be based, in part, on proof of what the violator knew when he committed the prohibited act. Given the nature of shipments or other human-directed movement of fish and wildlife into the U.S. and across state borders, H.R. 511, if adopted by Congress in its current form, would require a heightened standard of proof before prosecution could occur, significantly weakening our ability to use this statute to prevent or inhibit the spread of such species and the harm they cause. 

For example, the statute applies to a wide variety of animals such as mollusks, mussels, and crustacea that may be brought into the United States in ballast water or on the outside of ships.  As explained further below, the introduction of these injurious animals has caused enormous economic and environmental harm in this country.  While ship owners and operators are warned through posted signs and notices of their responsibility to appropriately dispose of ballast water and clean their ships to prevent the spread of injurious species, under the statute as amended U.S. prosecutors would be required to prove that they knowingly imported these injurious animals into U.S. waters in order to prosecute them for violations of this statute, an almost insurmountable burden of proof under the circumstances.  Thus, changing the prohibition in the statute from a strict liability offense to a knowing offense would remove the incentive for shippers to take appropriate steps to ensure that they do not introduce injurious animals into the United States. 

Furthermore, wildlife shipments can contain more than one species, and they may include individuals representing species listed as “injurious wildlife” among other, more benign species.  Injurious species may also be transported into the United States or across state lines as “hitchhikers.”  Also, this statute’s prohibitions against importation and transport of “injurious wildlife” involve, in many cases, specific species, but shipments may be labeled at a higher level of taxonomy. Species in these groups may look much alike. Importers may work with foreign partners who have no accountability to domestic law. Importers may or may not fully understand the content of their shipments in such cases. Such a shipment may include injurious species with or without the knowledge of the importer, who may or may not know such prohibitions exist. Under current law, Service enforcement agents may stop and detain suspected shipments, and when appropriate, pursue prosecution for the party who is accountable to U.S. law, with the goal of preventing the damage that these species cause. The mere prospect of prosecution on the basis of the presence or absence of the prohibited species in transport encourages knowledge of and compliance with the law.  The risk of spread of injurious species into the United States is, therefore, reduced by the diligence of the importer or transporter that is subject to the law.

The economic and environmental damage

injurious wildlife and other foreign, invasive species can cause to United States interests when those species spread into supportive habitats is well-known.  Species listed as “injurious wildlife” in many cases have already proven to be harmful, incurring considerable costs to reverse or control the damages they cause and to control their numbers in the wild.  These costs are ultimately borne by our nation’s businesses, consumers, and taxpayers when these species impact commercially valuable fisheries, water and power utility infrastructure, environmental quality and environmental restoration efforts, agricultural interests, and human health, among other things.

While precise estimates of annual costs are difficult to establish, the most widely referenced paper on this issue (Pimental et al. 2000) reports the cost of invasive species, which would include injurious wildlife, at $120 billion per year[1].  In 2011 alone, the National Invasive Species Council estimates that Federal agencies spent over $2 billion on activities focused on preventing, minimizing, or reversing the damages caused by invasive species, with more than half of that amount dedicated to prevention, rapid response, and control of such species and their impacts[2]. The risk of increasing these costs to our Nation’s interests with new introductions or human-facilitated spread is high, even when just a few individuals from species on this list are released or accidentally escape captivity.  The risk of escape or release of these species is particularly high during transport, and many of the species in the “injurious wildlife” list can reproduce and spread rapidly under suitable conditions. 

The transport of zebra mussels (Dreissena polymorpha) on recreational or commercial boats across state lines or our international borders often occurs without knowledge of the transporter about the law prohibiting this or the presence of the mussels.  In fact, the introduction of zebra mussels into the United States was through ballast water discharge of ships sailing from Europe into the Great Lakes.  This unknowing and unintentional introduction has cost the United States billions of dollars in damages and in control efforts. The threat continues to move west.  Invasive, fresh water mussels, including zebra mussels, transported across state lines threaten the hydroelectric infrastructure in western states.  These mussels are poised to invade the Columbia River, and the cost to hydroelectric infrastructure alone could be between $250 to $300 million annually[3].

Under the “strict liability” standard of current law, the Service's Office of Law Enforcement and the Department of Justice take into consideration mitigating and aggravating circumstances when deciding whether to file formal charges, issue a violation notice, or simply seize a shipment.  There is a significant amount of discretion applied on a case-by-case basis, maximizing the protective purposes of the statute without unduly hindering commerce or otherwise lawful activities of U.S. citizens. The cost of this prevention tool is a small fraction of the cost to control or reverse the damage of these species when they are able to establish wild populations in the United States.

The exemption provided in the amendment for the importation and interstate transport of the relevant species of large, constrictor snakes, from a practical point of view, would challenge the enforcement of the prohibition in such a way as to significantly reduce or eliminate its effectiveness in preventing the introduction or spread of these species in wild habitats in the United States.

The Service cannot support H.R. 511 as amended by the House Judiciary Committee.  The Service believes that the current “strict liability” standard for prosecution is necessary to achieve the protective purposes of this statute to manage the risk posed to U.S. interests by “injurious wildlife” species. We welcome the opportunity to work with the Committee to address any concerns about the current text or enforcement of this statute.

[1] Pimentel, D., L. Lach, R. Zuniga, and D. Morrison. 2000. “Environmental and Economic Costs of Nonindigenous Species in the United States.” Bioscience, 50(1): 53-56.

[2] National Invasive Species Council. November 1, 2012. Invasive Species Interagency Crosscut Budget.

[3] IEAB.  2010.  Economic Risk Associated with the Potential Establishment of Zebra and Quagga Mussels in the Columbia River Basin.  NW Council, Independent Economic Analysis Board, Task Number 159, Document IEAB 2010-1, July 14, 2010.  Available: http://www.nwcouncil.org/library/ieab/ieab2010-1.pdf (Accessed Nov. 23, 2012).