I met Leah on the trail near Lost Valley Spring. She has an amazing summer job in that, although the pay is not going to make her wealthy, makes her quite happy. She birdwatches, camps and hikes, working as a researcher for the San Diego History Museum. Leah walks a section of Desert Chaparral along the Pacific Crest Trail each morning listening and looking for a somewhat plain little songbird called the Gray Vireo.
It is a drab bird with a thin white eye-ring and pale lores (the color between the front of the eye and the bill). The Gray Vireo has a faint white wash on its wings. Other ten those marks it is pretty much gray. It makes a harsh “sch-ray,” call and a thin musical song. Leah had a wonderful ear for finding this bird and many others.
The population of this song bird, while not on an endangered species or threatened list, is of concern to some local breeding regions. The decline of the Gray Vireo in San Diego County was thought to be due to a combination of habitat loss and Cow Bird predation. Recently, a researcher noticed the increase and expanding population of the Western Scrub Jay and wondered if there was a connection to the decline of the successful fleshing of young birds. Grant money is funding research learn more about the nesting habits of this songbird.
When Leah finds a tiny grassy cup like nest she next oberves to learn when the eggs are laid. Leah pulled out a mirror on a long retractable handle. She walked into the brush and carefully extended the mirror to show the inner nest. There were no eggs this time but once the clutch is made Leah will install a tiny camera to film the incubation, hatching and (hopeful) fledgling of young.
Leah has watched the Western Scrub Jay rob a nest of both eggs and young birds. I have watched Blue Jays and American Crows feast on young Robins. It is heartbreaking but nature makes sure that everyone gets a meal. The Gray Vitro will try again and again to raise a batch of young birds, rebuilding its nest each time until the season is done and migration calls. Most sources say they will try only twice but folks in the field think it is more.
As we walked the trail together and Leah called out the birds by call or song. “Ash-throated flycatcher, Bewicks’s Wren, Western Scrub Jay, Gray Vireo,” she sorted through the layer of early morning bird song. I wish I could take her on my hike!