Slightly edited from an article as first published in the Phainopepla in November of 2002
This spring I worked as an intern with the Point Reyes Bird Observatory. Our study took place at the Cosumnes River Preserve, located 30 minutes south of Sacramento. The Cosumnes River is unusual in that it is the only undammed river west of the Sierra Nevada. The season not only consisted of an unusual river, but some very unusual birds as well.
My dwelling for the season was in a shack....a literal shack located on the preserve with only a small living room area, a set of bunk beds and a kitchen sink. Our bathroom was a port-a-potty located in our "yard" and our shower was a 3-walled stall out in our yard as well. The shower had no door, so if a farmer happened to drive by while you occupied it, he would get a nice surprise. We eventually bought a large piece of plastic to slide in place to act as a shower door, but this did not help to keep out the many frogs, black widows, and various other insects that liked to share our shower with us. We had the occassional snake come into the shower stall as well, most likely looking for frogs to eat. I usually poked them with my finger to scare them away. The frogs got to stay as they supplied a very musical shower since all of them would start to croak as they got wet.
We had other guests as well, the occassional rat could be seen on our porch leaping into our trash can. Once again, literally leaping from our porch railing, all four legs extended out, looking more like a flying squirrel than a rat, and landing right in our trash. I once came home to hear scratching coming from inside our laundry detergent box which was also stored on our porch, and feared I would open it up to find a rat leaping out at me. It ended up being a Tree Swallow that thought the box was a cavity for nesting. Another morning I put my rubber boots on only to feel something squishy inside them. It ended up being a frog that I had to pull out, rinse off with water and release.
The project consisted of nest searching and monitoring of several species: Song Sparrows, Common Yellowthroats, Wrentit, Spotted Towhee, Black-headed Grosbeak, Western Wood-Pewee, and Black-chinned Hummingbird to name a few. We found a number of cavity nests as well for species such as the House Wren, Tree Swallow, and Downy Woodpecker. We also performed point counts and ran a MAPS mist netting/banding station. We color banded Song Sparrows to distinguish one territorial male from the next. These bands will be used to find birds again next year so that their movements can be monitored.
The two sites or "plots" that I nest searched were a mature Valley Oak riparian forest and a much younger Fremont Cottonwood/Sandbar Willow "forest". Besides these forested areas, much of the preserve consists of organic rice fields. By the time the land was sold and protected there was not much left that was not being used for crops. However, the preserve requires that a majority of the fallow fields are flooded to act as a refuge for waterfowl and a feeding area for shorebirds. We saw a variety of birds in these fields, including Wilson's and Red-necked Phalaropes, American Avocet, Black-necked Stilt, Long-billed Dowitcher, Greater Yellowlegs, Least and Western Sandpipers, Cinnamon Teal, White-faced Ibis, Great Egret, Caspian Tern, and a rare sighting of a pair of Black Terns, not usually seen on the preserve during the time period we spotted them.
Another rare finding revealed itself when I took over the monitoring of a nest found by one of my co-workers on my plot. He told me it was an Anna's Hummingbird nest. My supervisor told me it was more likely to be a Black-chinned, as the Anna's are not typical nesters there. So, I set out to ID the bird, but because the nest was located rather high up in an Oregon Ash, backlit, and the bird was incubating, I could only see her head sticking out of the nest. I tried to make it into a Black-chinned, but the neck was not skinny enough, and I could not quite make it into an Anna's either. It was not until sometime later that I was able to get a good look at the bird, when the chicks had hatched and I observed her going to the nest to feed. At this time I was able to ID the bird as neither a Black-chinned nor an Anna's, but in fact a Selasphours species. I told my supervisor about the findings, but she was a little skeptical as Selasphorus hummingbirds do not nest there. We then informed John Trochet, a local bird guru, about the nest. He came down equipped with not only binoculars, but a scope, camera, and a hummingbird feeder as well. He verified that it was in fact a Selasphorus species. After contacting several people who are responsible for monitoring such bird data, it was determined to be an Allen's Hummingbird, the first record EVER for this species nesting in the Central Valley. The nest was successful, and two young were fledged. I saw the female a couple of times after the "kids" were gone, but she moved on and was not seen again. I got to write up my findings and it was published in The Central Valley Bird Club Bulletin.
Another of my co-workers found a Lesser Goldfinch pair nesting on her plot. Although there were past records for them nesting in the Central Valley, there were none of them ever having nested on the preserve itself. Our "sister" project, located further south, on the San Joaquin National Wildlife Refuge, turned up a nesting pair of Yellow Warblers. This was the first record of them nesting in that area in approximately 40 years. We also had verification from John Trochet that Dark-eyed Juncos were nesting on the Cosumnes for the third year in a row, and suspicions that a pair of Swainson's Thrush were nesting on the preserve as well, but could not prove it. If he had, that also would have been a great find as the last record for them nesting on the preserve dates back to the 1870s. One last surprise was the appearance of a male Indigo Bunting towards the end of the season. This was the first sighting on the preserve since 1998.
Besides all these rare finds, the rest of the season was a success as well, with our nest count totaling more than 300 and 135 species seen on the preserve.
