Featured Research

from universities, journals, and other organizations

Poisons on public lands put wildlife at risk

Date:
July 13, 2012
Source:
University of California - Davis
Summary:
Rat poison used on illegal marijuana farms may be sickening and killing the fisher, a rare forest carnivore that makes its home in some of the most remote areas of California, according to veterinary scientists.

Rat poison used on illegal marijuana farms may be sickening and killing the fisher, a rare forest carnivore that makes its home in some of the most remote areas of California.
Credit: Image courtesy of University of California - Davis

Rat poison used on illegal marijuana farms may be sickening and killing the fisher, a rare forest carnivore that makes its home in some of the most remote areas of California, according to a team of researchers led by University of California, Davis, veterinary scientists.

Researchers discovered commercial rodenticide in dead fishers in Humboldt County near Redwood National Park and in the southern Sierra Nevada in and around Yosemite National Park. The study, published July 13 in the journal PLoS ONE, says illegal marijuana farms are a likely source. Some marijuana growers apply the poisons to deter a wide range of animals from encroaching on their crops.

Fishers in California, Oregon and Washington have been declared a candidate species for listing under the federal Endangered Species Act.

Fishers, a member of the weasel family, likely become exposed to the rat poison when eating animals that have ingested it. The fishers also may consume rodenticides directly, drawn by the bacon, cheese and peanut butter "flavorizers" that manufacturers add to the poisons.

Other species, including martens, spotted owls, and Sierra Nevada red foxes, may be at risk from the poison, as well.

In addition to UC Davis, the study involved researchers from the nonprofit Integral Ecology Research Center, UC Berkeley, United States Forest Service, Wildlife Conservation Society, Hoopa Tribal Forestry, and California Department of Fish and Game.

"Our findings were very surprising since non-target poisoning from these chemicals is typically seen in wildlife in urban or agricultural settings," said lead author Mourad Gabriel, a UC Davis Veterinary Genetics Laboratory researcher and president of the Integral Ecology Research Center. "In California, fishers inhabit mature forests within the national forest, national parks, private industrial and tribal community lands -- nowhere near urban or agricultural areas."

Researchers analyzed 58 fisher carcasses and discovered that 79 percent of them had been exposed to anticoagulant rodenticides. Brodifacoum, a second-generation rodenticide, was found in 96 percent of the exposed fishers.

Second-generation rodenticides are more toxic because they can be lethal after a single ingestion. It can take up to seven days before clinical signs appear, so the poisoned animal can be a significant risk to predators for several days before it dies.

"I am really shocked by the number of fishers that have been exposed to significant levels of multiple second-generation anticoagulant rodenticides," said pathologist Leslie Woods of the UC Davis California Animal Health and Food Safety Laboratory System, which conducted the necropsies.

Anticoagulant rodenticides inhibit the ability of fishers and other mammals to recycle vitamin K. This creates a series of clotting and coagulation problems, which may lead to uncontrollable bleeding.

Exposure to the poison was high throughout the fisher populations studied, complicating efforts to pinpoint direct sources. The fishers, many of which had been radio-tracked throughout their lives, did not wander into urban or agricultural environments. However, their habitat did overlap with illegal marijuana farms.

The researchers describe a recent example in which more than 2,000 marijuana plants were removed by law enforcement officials less than 7.5 miles from one of the study areas. Large amounts of rodenticide were observed around the marijuana plants and along plastic irrigation lines.

The fisher deaths occurred between mid-April to mid-May, the optimal time for planting young marijuana plants outdoors -- and the time when seedlings are especially vulnerable to pests. This is also when fishers are breeding and raising their young.

Gabriel said fishers may be an "umbrella" species for other forest carnivores. In ecology, an umbrella species is one that, if protected, results in protection of other species, as well.

"If fishers are at risk, these other species are most likely at risk because they share the same prey and the same habitat," said Gabriel. "Our next steps are to examine whether toxicants used at illegal marijuana grow sites on public lands are also indirectly impacting fisher populations and other forest carnivores through prey depletion."


Story Source:

The above story is based on materials provided by University of California - Davis. Note: Materials may be edited for content and length.


Journal Reference:

  1. Gabriel MW, Woods LW, Poppenga R, Sweitzer RA, Thompson C, et al. Anticoagulant Rodenticides on our Public and Community Lands: Spatial Distribution of Exposure and Poisoning of a Rare Forest Carnivore. PLoS ONE, 2012 DOI: 10.1371/journal.pone.0040163

Cite This Page:

University of California - Davis. "Poisons on public lands put wildlife at risk." ScienceDaily. ScienceDaily, 13 July 2012. <www.sciencedaily.com/releases/2012/07/120713223935.htm>.
University of California - Davis. (2012, July 13). Poisons on public lands put wildlife at risk. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2012/07/120713223935.htm
University of California - Davis. "Poisons on public lands put wildlife at risk." ScienceDaily. www.sciencedaily.com/releases/2012/07/120713223935.htm (accessed July 24, 2014).

Share This




More Science & Society News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com
Thousands Who Can't Afford Medical Care Flock to Free US Clinic

Thousands Who Can't Afford Medical Care Flock to Free US Clinic

AFP (July 23, 2014) America may be the world’s richest country, but in terms of healthcare, the World Health Organisation ranks it 37th. Thousands turned out for a free clinic run by "Remote Area Medical" with a visit from the Governor of Virginia. Duration: 2:40 Video provided by AFP
Powered by NewsLook.com
Six Indicted in StubHub Hacking Scheme

Six Indicted in StubHub Hacking Scheme

AP (July 23, 2014) Six people were indicted Wednesday in an international ring that took over more than 1,000 StubHub users' accounts and fraudulently bought tickets that were then resold. (July 23) Video provided by AP
Powered by NewsLook.com
9/11 Commission Members Warn of Terror "fatigue" Among American Public

9/11 Commission Members Warn of Terror "fatigue" Among American Public

Reuters - US Online Video (July 22, 2014) Ten years after releasing its initial report, members of the 9/11 Commission warn of the "waning sense of urgency" in combating terrorists attacks. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins