Boa constrictor
photo by Wikimedia Commons
One of the country’s leading conservation groups wants Congress to ban imports of reticulated pythons, green anacondas, boa constrictors, and two other constrictor snakes that pose a major threat to native wildlife. In a letter sent the U.S. House Resource Committee, American Bird Conservancy says these snakes should be added to the list of “injurious wildlife” regulated by the Lacey Act, one of America’s oldest conservation statutes designed to protect wildlife from illegal trade. The change would make importing or transporting these snakes over state lines a federal offence.
“This bill (H.R. 511 –To Prohibit the Importation of Various Injurious Species of Constrictor Snakes) is necessary to prevent the further spread of these aggressive, invasive predators,” said Darin Schroeder, Vice President for Conservation Advocacy at ABC. “It’s well-established that these snakes are highly adaptable to new environments, and that they consume a wide variety of prey, including mammal, amphibian, lizard, and threatened and endangered bird species.”
Mr. Schroeder says fast-breeding and long-lived constrictor snakes have already done tremendous ecological damage in the state of Florida, where people who originally bought the snakes as pets have released them into the wild. The Burmese python, for example, is now estimated to have a breeding population in Florida in the tens of thousands. In a recent study, scientists collected more than 300 Burmese pythons in Everglades National Park and found that birds, from the five-inch-long House Wren to the four-foot-long Great Blue Heron, accounted for 25 percent of the python’s diet in the Everglades.
Mr. Schroeder adds that wildlife in the Hawaiian Islands could face similar devastation if constrictors or other snakes were to become established there. According to a 2001 study titled, Risk to Hawaii from Snakes by Fred Kraus and Domingo Carvalho, and published in the peer-reviewed journal Pacific Science, there was a yearly average of 24 snake sightings, mostly free-roaming animals that were not recovered, reported state wide between 1990 and 2000. For ABC, that concern is heightened by facts that most of the species recovered feed largely on birds, and by the fact that 70% of all native Hawaiian birds are already either listed as threatened or endangered or of conservation concern. More than one third of all bird species listed under the U.S. Endangered Species Act are Hawaiian.
“If snakes were to reproduce and proliferate, it quickly may be too late to stop them, and as a result, every measure to keep them out of places like Hawaii needs to be taken,” said Mr. Schroder in the letter. ”ABC strongly supports H.R. 511 and urges the full committee to take up and pass this important piece of legislation and send it to the floor of the House for full consideration.”
The best-known example of the damage a non-native snake can do can be found on the island of Guam, where the brown tree snake was accidentally introduced to from its native range of New Guinea and Australia after World War II. The problems caused by those invasive snakes were not limited to the near-total devastation of the island’s bird life: they also include major disruptions of electric power transmission, telephone service, military operations, computers, and tourism. Preying on eggs and birds alike, the brown tree snake has caused the extinction of nine of the eleven native land bird species on Guam.