Redwood Coast news
Last weekend Steve Linsley and I went on a 2-day, 3-night trip to the coast of N California and extreme S Oregon. The results were not what we expected.
(1) We didn’t see any interesting large mammals in a few hours of night driving in and around Hoopa Valley, but we saw record numbers of grey foxes throughout the trip.
(2) Rodent numbers seemed very low. We didn’t see a single squirrel or chipmunk (we weren’t intentionally looking for them, but normally they are everywhere), and didn’t catch or spot any voles (despite considerable effort) even in places where they were common in the past. The only rodents we caught were one very skinny dusky-footed woodrat and modest numbers of Keen’s mice (probably also one western harvest mouse, but that trap didn’t close). Interestingly, at one site there were lots of Keen’s mice in a grazed field but none in the adjacent forest. I suspect that voles have recently peaked and crashed (hence high fox numbers), and the mice are kind of filling their niche while it’s temporarily vacant.
(3) We got one shrew (Throwbridge’s) in ~20 pitfall trap-nights, which is more or less an average result. Interestingly, it was in the only trap made of coffee can (others were made of plastic water bottles). Likely a coincidence, but of a kind smart people don’t ignore 🙂 If you find me a bit agitated in the next few months, that’s because I’ll be drinking a lot of coffee.
(4) Finding good trapping sites for wetland-associated voles and moles proved surprisingly difficult. Next time I’d rather go to central Oregon coast where such habitats are abundant and soils are softer. Putting even ten pitfall traps into a mix of tree roots and pebbles was too much work.
(5) The highlight of the trip was watching a coast mole foraging on surface (in Stagecoach Hill Azalea Reserve in Humboldt Lagoons SP). I haven’t done an exhaustive literature search yet, but it looks like this behavior has never been observed in this species before, although there are records of cat kills and bones in barn owl pellets, interpreted as those of dispersing juveniles. The mole we saw (and photographed) seemed to be within adult size range, although near the lower end. I think it was the quietest mammal I’ve ever managed to find by sound.
Vladimir
7 Comments
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vdinets
No problem – we know PNW is tricky. But some of the places we visited had been really good for chipmunks in the past, and we didn’t see any Douglas’s squirrels, either.
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vnsankar
That’s weird that you didn’t see any Douglas Squirrels up there. I always rustle up a few… Numbers must really be down. Coast Mole ain’t easy though; I still haven’t seen one.
Also, one question–is Keen’s Mouse in NW CA/SW OR? I always thought the ones I’ve seen up there are just regular Deer Mice.
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vdinets
That’s a difficult question. The original study that proposed separating two species in the region involved only animals south to NW Washington, and subsequent works took it to be the S limit of P. keeni‘s distribution. The two forms differ in chromosome structure and mtDNA, but are almost identical in nuclear genes (see this study. More recently it’s been suggested that all coastal and Coast Ranges mice south to Golden Gate should be called P. keeni (I think it was this study, but I don’t remember for sure and I can’t access it at the moment). From my experience, mice in coastal Oregon are as long-tailed and arboreal as the “typical” P. keeni up in British Columbia, just less dark, while those in NW California are also shorter-tailed. All this gets ever more complicated. There are also suggestions to split P. maniculatus into 3-12 species.
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Matt and Maureen
We’re in California right now, and interestingly have had no luck with chipmunks either – though up in the mountains we just figured they’re still hibernating. Also saw lots and lots of grey foxes at Point Reyes (7 sighted, vs 1 bobcat and 4 coyote).
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vdinets
They should be out of hibernation by now, except in places where there’s still a lot of snow on the ground. In the winters of 2013-2014 and 2014-2015 some were active around Lake Tahoe all winter.
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ameet
I re-discovered this thread and I would echo the remark about the paucity of Sciurids. I drove around 500 miles over the 4th of July weekend (Redding – Trinity Lake – Hoopa Valley – Grayback Rd – Jedediah Smith Redwoods SP – Happy Camp – Yreka). I did not do any spotlighting. I did take a detour on a small side road to Fish Lake. Through all this driving the only mammals seen were 3 Western Gray Squirrels, 1 Siskiyou Chipmunk (by the Smith River near Jedediah Smith Redwoods SP) and several deer. Surprisingly I did not see any Douglas Squirrels or any other chipmunks.
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vnsankar
Hey Vladimir. Sorry to hear this…
That said, I need to mention that NW CA has been very, very hit or miss for me too with the mammals though. On my first trip (when I put in the most night driving), I had Snowshoe Hare, N Flying Squirrel, W Red-backed Vole, and an Aplodontia den site and Fisher scat. In the next couple of trips I did, I’ve only seen Black Bear and Chipmunks. At any rate, I find night driving in NW CA a crapshoot. I see really interesting stuff maybe 1 in 5 night drives even on good roads.
Even chipmunks can be tough to pin down in NW CA. You need very specific locality data. Outside of Forest Route 1 and Friday Ridge Rd, the number of sciurids I’ve seen on the coast is single digits despite a lot of effort (1 W Gray Squirrel in Redwood NP and Siskiyou Chipmunk at a stakeout site near Jedediah Smith Redwoods SP). Allen’s is easy though at certain sites on the coast. On Friday Ridge and Route 1 roads though, you can easily see 7 species of Sciurids in a day with a little luck; this is the only site where it’s this easy though. Surprised you didn’t get any voles – that said, Tolowa Dunes (very near Oregon border) has been better for me than Redwood NP lately.
Pretty much the only reasonably “guaranteed” species up there are Roosevelt Elk, Deer, Black Bear, Raccoon, Gray Fox, and provided you have stakeouts Chipmunks and maybe W Gray Squirrel.