San Diego Natural History Museum--Your Nature Connection[San Diego County Bird Atlas Project]

WRENDERINGS
Reports from the Field
Winter 2001

Treasures of San Felipe

Sketch of Summer Tanager

Summer Tanager

In his provocative new book Heartsblood David Peterson asserts that the only way to experience the highest bond with nature is through hunting with the intent to kill. No one could dispute the intensity of the personal adrenaline rush he gets hunting, but I do challenge his assumption. I contend that a form of hunting is exactly what I am doing at San Felipe Creek, and it brings me as close to nature as any experience (I hunted, with a gun, from age 5 to 20). At least now when I head home, the birds live to fly another day.

The recent discoveries made beneath the creek's 60 acres of woodland canopy are proving crucial to impending management decisions in Anza-Borrego Desert State Park. The site is about 12 miles east of Julian and extends 1.5 miles upstream (north) and about a mile downstream (south and east) of State Highway 78 (atlas squares I21, J22, and J23).

I had birded short sections of the creek a few times in the 1970s and 1980s, and began a more thorough coverage in 1993 in my job as a park biologist. It was appalling how little I and others had uncovered compared to what was to be found. No one predicted the exciting new finds that awaited, nor how much fun it would be making each discovery. Although I'm not obsessed with ticking off lifer birds, I have somewhat exhausted the local opportunities. With Costa Rica and Africa temporarily out of reach, some of us have to get our kicks by documenting local range expansions and the like.

When the San Diego Bird Atlas started, and coincidentally, California State Parks purchased 1700 formerly very private acres along this section of the San Felipe Creek, several of us began the first intensive bird surveys along this gently flowing creek. New important breeding and wintering data started to pile up as Bill Haas, Ed Hall, Larry Hendrickson, Mark Jorgensen, Phil Nelson, Bob Thériault, Phil Unitt, Jeff Wells, Terri Gallion, Jim Zimmer and I, armed with binos and atlas data forms, took a much closer look.

Amid desert dryness and heat, San Felipe Creek has produced magical surprises. Most of these surprises have come in the form of riparian birds; that is, birds that can't survive without streamside woodland habitat.

Imagine Bob Thériault's excitement as he stalked the first known Anza-Borrego pair of Summer Tanagers in mesquite in J23, trying to confirm breeding. Mark Jorgensen was surprised to find a rare (for the desert) Cooper's Hawk nest with nestlings while walking under a big Fremont's cottonwood in J22. Jeff Wells and I pursued a bright red male Summer Tanager that flew over us with a round object in its bill (not good enough in our mind for San Diego County's first nesting confirmation). Visiting biologist Terri Gallion found a family of Western Screech Owls above her field campsite. The sharp ears of Bill Haas and Phil Unitt picked out a singing male Indigo Bunting as it chased a female Lazuli (Bill captured the song with his digital recording equipment). At dawn in J22, I watched a male and female Summer Tanager high above me in the canopy taking food into the first nest of the species I'd ever seen. Three hours later, Bob Thériault and I found the county's second ever Summer Tanager nest in his square J23, probably the same pair Bob had stalked the year before a half mile west in mesquite. Herb Stone and I strained our necks searching overhead in tall willows, finally finding an adult Pacific-slope Flycatcher feeding its fledgling. Bill Haas discovered San Felipe's first known breeding Southwestern Willow Flycatchers in his mist nets just outside the park's boundary. A group of us, including Jack Schlotte and Brennan Mulrooney, heard and briefly saw the area's first recorded Brown-crested Flycatcher, a Blue-gray Gnatcatcher, the above-mentioned Indigo Bunting and a territorial pair of Warbling Vireos--all within a half-hour. Other tantalizing finds over the last year include breeding evidence for the Northern Harrier, Oak Titmouse, Western Wood-Pewee, and Yellow Warbler. Active nests of Blue Grosbeaks, Bell's Vireos, and Yellow-breasted Chats were among the many riparian species found.

Our best bird answer to "charismatic megafauna" is the Summer Tanager. The birds have established a relatively dense, if small, breeding population along San Felipe's narrow, tall cottonwood/willow riparian woodland. Seven pairs were found in the year 2000, six pairs in 2001, with a fairly significant upstream section of privately owned creek not yet thoroughly surveyed. Like any nester, they face a gauntlet of threats. Terri Gallion spent three days (24 observation-hours) watching a pair carry out normal incubation duties at their nest in a willow over the creek, only to watch a Western Scrub Jay steal the eggs. The speculation as to how long they have been nesting here in the county will continue. Were it not for the bright red males, it no doubt would have taken us longer to discover them.

Sketch of Yellow-billed Cuckoo

Yellow-billed Cuckoo

Another very exciting find was made by Kern River researcher Terri Gallion. Last year I entertained a wild dream and played Yellow-billed Cuckoo tapes just for fun--I didn't find any. Terri volunteered to spend some "quality" time this July at the creek. Her knowledge and exceptional ability to hear and find birds (and dragonflies) paid off. Among her discoveries was the elusive and endangered Yellow-billed Cuckoo, which she encountered in tall cottonwoods north of Scissors Crossing. The cuckoo has been extirpated as a breeder in the county for decades, so its appearance streamside in the evening at her camp was a surprise. It gave a call indicating an unpaired male. She thought it was just moving through, but the next morning it reappeared. I refound what I assume was the same bird four days later on 12 July at the same location. Its slow-motion head movements while feeding added to the mystery of this unique species. It couldn't be located on several follow-up searches. We don't know if other cuckoos are present or if this assumed male found a mate.

Now, virtually every riparian-loving bird species known to inland southern California has been found at San Felipe.

San Felipe Valley has been well known for years among lepidopterists as an extraordinary location for a variety of butterflies. The valley has now revealed itself as a major corridor for migrant birds. For example, last spring Bill Haas counted over 600 Black-headed Grosbeaks passing by in a few hours.

What future discoveries and research await? The hunt for Yellow-billed Cuckoo breeding will intensify--I know it's my first priority. Documenting breeding for the Brown-crested Flycatcher, Warbling Vireo, and Indigo Bunting are certainly within reason. Finding the Long-eared Owl seems possible. And what about the California Black Rail (or even Clapper Rail)? I've been playing Black Rail tapes annually at Sentenac Cienaga (below Scissors Crossing) since 1976 without success, but I will continue there and upstream. What about the Least or even American Bittern? How about the usually coastal Downy Woodpecker? Is Swainson's Thrush out of the question? Lucy's Warbler is a stretch (but by only about 12 miles).

We have modest funds set aside to study the ecosystem next year in more detail. One possibility is to focus on the Summer Tanager. In addition to basic population questions, its taxonomy is fascinating. Known migrants and residents here in southern California are different subspecies, so we want to know how this new local population fits into the puzzle. The abrupt removal of long-term cattle grazing on a riparian system merits an ecosystem-wide study. Who will carry out the work? Are there interested scientists out there (we even have housing available for guest researchers)?

Park management of the area will focus on clean-up and habitat restoration for the next few years. We just got $250,000 to begin tamarisk removal in fall. The cost of that task alone is estimated at $1,000,000 over five years. After initial intensive removal, routine annual exotic plant control will be required forever. Staff is looking into the best location for a nature trail, one that provides good streamside public access to the Summer Tanagers and other attractions yet protects the integrity of this thriving riparian ecosystem.

Walk to a knoll overlooking the creek, as botanist and park ecologist Jim Dice did on a recent afternoon, and listen to the sound of ten or twenty species of birds competing for air time. Jim was impressed with the beautiful green woodland and the obvious abundance of life before him (Jim was among those instrumental in obtaining acquisition grants for this land).

Much has been written about the valley as a corridor for human migration over the last two centuries. Kit Carson, General Kearney, the Mormon Battalion, and John Coulter passed through, and it was part of the Southern Emigrant Trail and the Butterfield Overland Stage. Now its proper place in the natural world is being unveiled.

--Paul Jorgensen, Resource Ecologist, Colorado Desert District, California State Parks

birdatlas@sdnhm.org

Winter 2001 Wrenderings | Wrenderings Archive | Bird Atlas Introduction