mjm@oliven.olivetti.com (Michael Mammoser) (01/26/88)
John, My experience with the black rails at the Palo Alto Baylands only goes back a couple of years. However, I have heard from other people that this is a recent population; becoming established only in the last decade. Studies indicate that the rails are not there in the breeding season. This raises a few interesting questions. Like: where do they go in summer? Are they part of a migratory midwest population, or do they just go to the north end of the Bay (where a breeding population exists)? Why such a recent establishment at this site? Were they forced to leave a traditional wintering site (development?) to find a new home, or are they the result of a recent population expansion. I've also noticed some interesting plumage characteristics on these birds. They have the typical chestnut patch on the shoulders; however, the chestnut extends up the back of the neck onto the rear of the crown. On a few of the occassions that I have seen them fly, I have noticed a white wing patch of some extent on the underside of the wing; near the wrist joint, extending a little onto the leading edge of the wing. On a standing bird with folded wings, I have seen this white spot on the leading edge near the wrist that seemed to wrap around to the underside. I have not seen these character- istics described in any field guide, photograph, etc. I wonder if these are age, sex, seasonal, or subspecific characters. By the way, your map of the Baylands was perfect. The black rail site is as you indicated on the map; at the corner where the road turns. At the effluent outflow channel, on the side opposite the airport, there is a small path that runs the length of the channel. When you get on this path from the levee, you are almost immediately in an area of short, scrubby bushes and tall grass, bordered on one side by the channel and on the other by the marsh. This is the "normal spot" for sharp-tailed sparrows. They have been found here regularly in recent years. I saw the yellow rail in the transport box; I saw it through a car window while it was being hand-held for a photograph; I saw it fly into the marsh when released; and I still have a void on my life list for this species. The "laws" of birding say that an observation of a released captive made in the release area is not valid unless made more than 24 hours after the release. Needless to say, I never saw the bird again. I've had a lot of fun in the last 6 weeks or so, chasing rarities/ vagrants. Some new life birds include: tropical kingbird, great-tailed grackle, emperor goose, rock sandpiper, red-necked grebe, black-throated sparrow, summer tanager, and dusky-capped flycatcher. good hunting, Mike