"Some confusion with Iris macrosiphon with cream to gold-yellow perianths. " I macrosiphon has a flower "tube 34–65 mm, abruptly inflated, bowl-like at top." This flower seems to suit the description, "tube 35–60 mm, narrow, gradually funnel-shaped distally" particularly when i look at side images of nearby individuals. The leaves seem thicker, too, while I macrosiphon leaves are more spindly.
20 + individuals (adults) found in restored grassland. Courtship observed. Healthy population at Horse Park Woodside (private). No diagnostic photo - sorry :(
10 + individuals and restored grassland. Courtship observed
Calathus ruficollis (Carabidae, ground beetle), Redwood City, San Mateo County, California - 27 November 2010. Thanks to v belov and Bug Guide for the species-level identification: bugguide.net/node/view/475550 Appears to be quite common in the Bay Area.
Seems to have moved into my backyard. And there are at least two of them.