Yesterday I went over to the Seymour Center to talk to the person at the front desk about arranging a field trip visit for a class I'll be co-teaching this summer. When I walked through the exhibit hall into the office wing there were a couple of staff members coming the other way down the hall, gesticulating excitedly towards the door that leads to the garden area on the coastal bluff. My first thought was "Whale!" but when I looked out at the water I couldn't see anything of particular interest in the water.
"No! Look on the wall!" they said.
"What? The barn swallows?" I asked. There were two swallows flying around under the patio. Why are they getting all excited about barn swallows? I asked myself. They kept pointing so I went over to the window for a closer look and saw this creature hanging on one of the light fixtures:
It's a bat! A very small one, about the length of my thumb and about twice as wide due to the fur. It had chosen the light fixture for its daytime roost and was sleeping. Here's a picture of its little face:
I know very little about the bat species in California. However, I did some poking around and now am fairly certain that this bat is in the genus Myotis, possibly M. californicus. There are many other species of Myotis, collectively referred to as mouse-eared bats because of their long ears.
Yesterday I couldn't stick around long enough to see if the bat would fly at dusk. I think that quite often daytime roosts are temporary, so there's no reason to expect the bat to return. Tomorrow I'll be at the lab most of the day and will be able to see for myself.