Renewable Revolution

'Truly astounding': inside the Farallon Islands' battle against a plague of mice

theguardian.com - The Farallon Islands of northern California are one of the world’s great biodiversity hotspots. These stark granite outcrops, which sit 30 miles (1.6km) off the coast of San Francisco, are home to 30…

Read more Doomstead Diner Daily 11/28/19

I totally agree with this quote from the article:

With more than a thousand mice per acre, an ecosystem is under threat. But poison could make things even worse.

I looked up Brodifacoum "rat" poison. They call it a rat poison because it was developed to deal with mice that were resistant to Warfarin (an anticoagulant rat poison that causes mice to hemorrhage and die). However, Brodifacoum, also an anticoagulant, as the article you posted mentioned, will kill all sorts of animals, including 🦉 owls.

/BIRDS and MAMMALS/ Owls (Bubo virginianus, Aegolius acadicus, Tyto alba) died of hemorrhaging after feeding on rats killed with brodifacoum.

Here's how it affects humans:

HUMAN EXPOSURE: The target system is the hematological system, with impairment of clotting. The main risks are associated with potentially fatal gastrointestinal and intracerebral hemorrhage. If toxic amounts have been ingested, coagulation will be impaired, with gum bleeding, epistaxis, ecchymosis, hematomata, hematesis, melena and hematuria. Oral exposure is the commonest route of entry. Brodifacoum is readily absorbed in the gastrointestinal tract. The ingestion of a large amount of brodifacoum over a two day period by a 31yr old psychotic woman produced generalized ecchymosis and abortion. A 17 yr old male ingested brodifacoum had flank pain and hematuria followed by epistaxis and gum bleeding. In an adult ingestion of brodifacoum produced bleeding for more than two months. In a longitudinal analysis of alterations in specific coagulation factors in a poisoning case demonstrated a profound decrease in factors II, VII, IX and X. The prognosis is poor in cases with internal bleeding or intracerebral hemorrhage and in patients with previous hematological illnesses or renal insufficiency. Muscular hematoma may result, especially on the elbows, knees and buttocks. Although the liver is the site of metabolism of brodifacoum, no observable clinical effects are apparent except coagulopathy.

Because humans are bigger in size than most animals that happen to ingest brodifacoum, the impairment of clotting on small animals is worse.

ANIMAL STUDIES: Brodifacoum and related compounds bind more strongly to a lipophilic site in the liver than does warfarin. In the poisoned rat, hepatic concentrations of the substance are 20 times higher than the serum concentrations. Brodifacoum has a very long plasma half life. Metabolic studies in animals have shown a half life of approximately 24 days, 120 days in the dog and 156 hours in the rat. Brodifacoum is hydroxylated to inactive compounds by mixed function oxidase enzymes in hepatic microsomes. Phenobarbital is known to increase the activity of hepatocellular microsomal enzymes and would increase the anticoagulant's metabolism as it does with warfarin. In the animal, it has been demonstrated that pretreatment with phenobarbital decreases the effect of brodifacoum. This compound acts by inhibiting the vitamin K epoxide reductase in the vitamin K1-epoxide cycle. Impeding the cyclic regeneration of vitamin K1, resulting in hypoprothrombinemia. The superwarfarins produce a diminution of the vitamin K dependent carboxylation of glutamic acid residues in prothrombin factor precursors. The effect is 100 times greater on a molar basis than that of warfarin. With its very long plasma half life, results in a potent anticoagulant effect. Brodifacoum is slightly irritating when applied to the skin or rabbits and to the eye. No effect has been demonstrated with technical brodifacoum in long term carcinogenicity tests. Studies in rats and rabbits have demonstrated no fetotoxic, embryotoxic or teratogenic effects.

Learn more: BRODIFACOUM ☠️

The 🦉 owls have something to say about humans poisoning mice and a lot of other small animals:


I'm with the owls on this one, Yes, the owls kill petrels when the mice population crashes. But, Brodifacoum will kill the mice, the eagles, the owls and just about every other small animal on that island for a long, long time.

Yes, Brodifacoum  worked in several islands in the past to get rid of mice infestations. However, I will wager they didn't drop large amounts from helicopters like is planned in this instance. The helicopter blunt instrument massive poison approach is guaranteed to produce overkill. It will profit only those that sell Brodifacoum.

Yes, the cats and/or 🐍 snakes approach won't work because both cats and snakes are predators that seek the easiest prey, which in this case appears to be are the rare ashy storm petrels (and other nesting sea birds).

Owls turn on the rare ashy storm petrels only when they have no other prey available. Even so, the premise that the owls will end up wiping out the rare ashy storm petrels is, IMHO, flawed. Mice ARE the preferred prey of the 🦉 owls. The fact that the article singled out the ONE RARE species of sea bird the owls will eat when mice are not available makes me smell a Brodifacoum 😈 salesman RAT (pun intended). What about the significant percentage of the rest of the 300,000 breeding seabirds, five species of seals and sea lions, and a type of cricket found nowhere else in the world that will be sickened and/or killed by a massive helicopter drop of Brodifacoum?

I say bring more owl species to the Farallon Islands. Put owl nesting boxes all over the islands in places the mice go to feed. Owls know exactly what to do. They were designed to be night hunters. There is no other bird species, including eagles and hawks, that can compare with owls in mice hunting success.