Trip Report – A Couple of Days in California

Peromyscus californicus
California Mouse

I had a couple of nights in California earlier this month, which began in Boulder Creek, where Brian and Eileen Keelan put me up for the night at their lovely house deep in the Redwoods. Their backyard was full of Merriam’s Chipmunks, and we caught some fabulous California Mice nearby (the largest Peromyscus species).

Tamias merriami
Merriam’s Chipmunk

As soon as I’d dropped my bags, Brian and Eileen whisked me to Pinnacles National Park for the evening to look for Western Mastiff Bats. Using his bat detector, Brian was able to identify 10 species, some of which we also saw in flight including many of the fabulous Western Mastiff Bat, North America’s largest species, and our main target for the evening.

Pinnacles National Park
Pinnacles NP

I found the Mastiff Bats easy to hear with the naked ear, and we picked up several in the spotlight: their large size and colour, plus audible calls making them quite easy to identify. We also saw many Western Pipistrelles over the reservoir and at least one Californian Myotis flying up and down the trail near the carpark at 11pm (identified by Brian with the detector). Other species we recorded, but I wasn’t sure I saw, were Big Brown and Little Brown Bats, Silver-haired, Fringed and Western Dark-nosed Myotis, Pallid Bats and Townsend’s Big-eared Bats. Other mammals in the park that night included a Gray Fox and some Mule Deer.

The next morning I headed north to Lava Beds National Monument, where Brian had recommend Lava Beds as a good spot for California Kangaroo Rats, something Vladimir Dinets had confirmed in July. I dropped in on Vladimir in Davis for an hour and we visited some scrub on the edge of town and looked under many sheets of plywood. It was too hot and dry for many mammals but we did see a California Vole.

I arrived at Lava Beds after dark. California Kangaroo Rats were abundant and unusully confiding for Kangaroo Rats. I saw them in the Campground, many on the roads (especially in the north of the park), and along the Cave Loop road that leads from the Visitor Centre (and is closed to traffice after dark so makes for great spotlighting). I also saw at least one Great Basin Pocket Mouse (in the Visitor Centre car park).

Other mammals included Mule Deer, Pronghorn, Mountain Cottontails and Black-tailed Jack Rabbits.

Dipodomys californicus
California Kangaroo Rat

On my way to and from Lava Beds National Monument I visited the Battle Creek Campground (a mile west of the small town of Mineral) The campground was, at least in 2006, home to only one chipmunk species: Allen’s (Shadow) Chipmunk. I saw only one chipmunk in the mid afternoon, but found many the next morning. Most chipmunks seemed to be Allen’s but as so often is the case, I would not put stake much money on some of my IDs.

Tamias senex 2

Tamias senex 3

Tamias senex
Allen’s Chipmunks

Golden-mantled Ground Squirrels were very common, and I also saw several Douglas Squirrels and some Mule Deer.

Too much driving for 2 days but the scenery was pretty speccy


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