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The Farallon Islands, Ashy Storm-Petrels, mice, owls and brodifacoum | Los Angeles Times

December 15, 2021

[Posted by Chuck Almdale]

Could toxic airdrop balance nature?
Los Angeles Times | Steve Lopez | 15 Dec 2021 | 10 minute read

This Coastal Commission will be discussing this on Thursday 15 Dec 2021.
Here’s a few links: one of them should get your there.

Staff Report on Farallon plan
Virtual Hearing Procedures
Cal-Span Full Coverage Streaming
This might also access the streaming

Thousands of birds live on the Fallarons.
Rats there draw owls that also prey on Ashy Storm-Petrel eggs.
(Josh Edelson for The Times)

From the article’s introduction:

The mice of the Farallon Islands think they’ve got it made.

They’re out there with ocean views in every direction, picnicking on plants, salamanders and insects like there’s no tomorrow. But there might not be a tomorrow for the lowly rodents, because the United States government is gunning for them.

The Fish and Wildlife Service has found the mice indirectly guilty of serial murder in the death of seabirds and sentenced them to death by poisoning, with a key review of the extermination plan up this week before the California Coastal Commission.

Each year, burrowing mainland owls fly to the Farallones to feast on the teeming mouse population. When the mice population drops, as it does seasonally, the owls then eat the eggs of the ashy storm petrel, a bird some consider a future candidate for the endangered species list.

So the mice are essentially co-conspirators in the demise of the storm petrels, and the question is: How do you poison 60,000 or so mice who live on an island 30 miles off San Francisco?

Steve Lopez is an excellent journalist and author who has written hundreds of hard-hitting, factual and funny pieces. This is no exception. He’s not a birder though, so he does make the occasion gaff obvious to birders.

I love his above phrase “burrowing mainland owls,” but I wouldn’t go out on a limb and say just exactly what that’s supposed to mean. The default assumption would be “Burrowing Owls from the mainland.” If that’s correct, I’m surprised. Burrowing Owls are getting to be a rare breeding bird in California these days, as vast swaths of their former breeding territory have been covered with houses, farms and warehouses. But it might also mean any owl that has anything to do with burrows, such as sit at their entrance and wait for a mouse to come out and agree to be eaten.

Less confusing yet also amusing is “ashy storm petrel.” There are petrels and there are storm-petrels, and while they do meet o’er the wine-dark seas, they are in different avian families and cannot interbreed. [Go here and scroll about halfway down.]

These two nitpicky errors illustrate why I consider a bird species’ English name to be a proper noun, and always capitalize it. This eliminates confusion. You wouldn’t write “Steve mainland Lopez” would you? If he had written “mainland Burrowing Owl” we’d know for certain what he’s talking about, and by treating the species name Burrowing Owl as the proper noun name, not merely a description, you’re far less likely to insert adjectives and whatnot into the middle of the name. Likewise, we’ll know we’re talking not about an Ashy-storm Petrel, but an Ashy Storm-Petrel, two entirely different birds (the first is fictitious, the second is not).

This is, by the way, less important for mammals than it is for birds. Without doing an analysis of 5,000 mammal names, and 10,500 bird names, I’d say that more bird names than mammal names—both numerically and proportionally—are descriptive. A Yellow-throated Warbler is a particular species, but a yellow-throated warbler could be any of several dozen species that happen to have yellow on their throat. It might be any warbler whose throat is dusted with yellow pollen. In that sense, there hundreds of species of yellow-headed hummingbird.

I hope I’ve pounded that point into the ground.

And to confirm that Burrowing Owl is the species intended, read this from Point Blue.

Please read Lopez’ entire article, as it’s far more interesting and informative than my peevish expression of irkdom.

A few high points of the article:

  • 60,000 House Mice Mus musculus on the Farallons
  • Burrowing Owls Athene cunicularia fly over from the mainland to eat them (30 miles west of San Francisco)
  • When they run out of mice, or the mice get wise, the owls eat bird eggs, especially the bite-sized eggs (1.1 x 0.8 in., 1/4 oz) of Ashy Storm-Petrels Hydrobates homochroa
  • Various agencies want to dump 2,800 lbs. of pellets laced with brodifacoum, an anti-coagulant especially lethal to rodents
  • They’ll dump it on the high parts of the island
  • This has been done elsewhere with good results
  • Point Blue and other respected conservation agencies approve the idea
  • Other conservationists are horrified

My reaction to the article is: “Gee, what could go wrong with that idea?”

Incidentally, approximately 250,000 seabirds and shorebirds in twelve species nest on the Farallons: Western Gull, Brandt’s Cormorant, Pelagic Cormorant, Double-crested Cormorant, Pigeon Guillemot, Common Murre, Cassin’s Auklet, Tufted Puffin, Black Oystercatcher, Rhinoceros Auklet, Ashy Storm-Petrel, and Leach’s Storm-Petrel.

All capitalized. See, that’s not so hard.

  1. Julie permalink
    December 16, 2021 12:31 pm

    RATS (raptors are the solution) believe that the US Fish and Wildlife are taking this step without having first tried all possible non-poison options, such as contraceptives. So they and Poison-Free Malibu are advocating for other options to be tried first. I concur.


    • Chukar permalink*
      December 16, 2021 1:34 pm

      If anyone would care to lay out their reasons why this anti-coagulant is a bad idea in the Farallons, send it to me and I’ll post it.
      I don’t know enough about all that’s involved to have an educated opinion.
      I only know that this sort of biological control “oft times do do awry.” Importing mongoose to catch the rats in the sugar cane fields and that sort of thing.
      On the other hand, the New Zealanders have had very good success clearing the rats, cats and mice off their little barrier islands, and then (re)introducing their various species of extremely endangered endemic wildlife, like Stitchbirds and Kiwis.


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