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Last month we reported on bald eagles and other birds found dead after a rat eradication project in Alaska’s Aleutian Islands. The National Wildlife Health Center in Madison, Wis., has confirmed that the birds were casualties of brodifacoum, the poison used in bait scattered around Rat Island by helicopter.

“Every one of the liver samples tested positive for brodifacoum,” U.S. Fish and Wildlife Service spokesman Bruce Woods told Scientific American. Fish and Wildlife law enforcement agents are investigating whether there were any egregious errors and to assess that the poison drop was conducted according to an approved protocol, Woods said.

For two centuries, invasive rats on the island have ravaged populations of ground-nesting seabirds. In September, Island Conservation, the Nature Conservancy, and the U.S. Fish and Wildlife Service dropped rat poison from helicopters after an environmental assessment concluded birds were unlikely to be harmed because the rodents would perish in their burrows.

A recent census found puffins and other seabirds were returning to nest on the island in the absence of rats. But wildlife workers also discovered corpses from 43 bald eagles, 213 glaucous-winged gulls, and several other species. The scientists believe gulls may have consumed the poison cakes and were then preyed upon by eagles.

The wildlife lab reports that two bald eagles, two glaucous-winged gulls, one peregrine falcon, and one rock sandpiper all tested positive for the poison. The team plans to analyze more tissue and soil samples. Another team will return to the island in early August to look for any further mortality.

Conservationists still hope to eradicate rats from other islands in the Aleutian chain, but they may have to modify their approach. “When we get all the information,” Woods says, “we will attempt to figure out what we can do better.”  

Image of bald eagle courtesy Alaskan Dude via Flickr

8 Comments

1. 1. fishartgallery 08:16 AM 7/2/09

   . . discovered corpses from 43 bald eagles etc . . . Out of how many bald eagles in the resident population? Was that 1% of them of 90%? Perspective please.

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2. 2. Zeugitai 11:46 PM 7/2/09

   This predictable disaster was perpetrated by the species that arrogantly thinks it can safely manipulate genes, subatomic particles, chemical toxins, nuclear reactors, hormones, etc. Human arrogance--or hubris--is so far disproportionate to its critically important capacities for reason and restraint that because of it, both the planet and the species are doomed.
   
   Poor eagles. . .
   

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3. 3. JImmy Jack Russell 12:47 AM 7/3/09

   To balance the comments above, some thought should be given to the positives of eradicating the rats from the island. Now at least a natural ecology has some chance of returning to the island. To paraphrase many of the military speeches made by the Allied forces in their "eradication" of the "evil terrorist threat" : "There will be innocent lives lost in this noble fight" .... Only this time there has been a successful outcome and minimal loss of life. The Rats have been removed so that the rightful species can return and fill the vacant niches, previously smothered by the rat population. This action has nothing to do with Palin and everything to do with considered and intelligent conservation.

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4. 4. Celwyne 03:11 PM 7/3/09

   Once again we, man in his ultimate wisdom interferes and causes harm. Were the rats introduced by man in the first place I wonder.
   Why was not a better alternative used that did not kill other then the intended victims. Was it cost? time? We seem to have so little respect for some things. Would the same thing have been done in a kindergarden school that was inundated with rats. I think not as young children would be likely to pick up the poison thinking it to be a sweet etc or like many animals use their taste and smell to try it. We really need to re-think many things in this area.

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5. 5. brynn217 10:58 PM 7/4/09

   Umm.. for some odd reason, there was no mention if the object of the mission was achieved... How many Rats were killed? 1% or 90%... even if 10% survived, they will return in years to come..and History shall repeat itself..
   

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6. 6. AJ2511 05:20 AM 7/5/09

   How difficult is it to foresee that dropping poison onto an island will result in the deaths of animals other than those intended? Just because the box reads "Rat Poison" doesn't mean its contents will poison only rats! hehe:) If it were only that simple... Why was it so necessary to increase the ground nesting bird population anyway? Obviously they were making their habitat elsewhere.

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7. 7. Rarebird 03:40 PM 9/26/09

   Wow. Unbelievable the lack of facts with which many of you base your opinions. Do any of you get your information from more than one source? Maybe you should try reading the initial assessment study before this project began: http://alaskamaritime.fws.gov/pdf/rat_assessment_508.pdf, or some of the followup studies. This was an incredible achievement which is allowing the island to finally return to its natural state after over 200 years.

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8. 8. hair products for hair loss 03:58 PM 1/19/11

   I have heard many such arguements from conservationists here in england but the scientific facts are yet to stand up to scrutiny. I am all for the protection of native wildlife but am very cautious of hype from tenuous reports.

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