Ulistac Natural Area (Spring):
Enjoying Migration in an Urban Oasis
by Chris Johnson
Sitting adjacent to an avian flyway (the Guadalupe River), surrounded by suburban sprawl, and boasting the last remnant forest in the city of Santa Clara, Ulistac holds its own as a spring migrant trap. Enjoy the smell of native plants and trees in the restored areas of the park and witness the gradual process of forest regeneration.
Trip Covers: Spring migration (April-May)
Key Birds: Olive-sided Flycatcher, Western Wood-Pewee, Pacific-slope Flycatcher, Warbling Vireo, Swainson’s Thrush, Yellow Warbler, Wilson’s Warbler, Western Tanager
How to Bird
Navigating the Park: Ulistac’s compacted dirt trails are accessed from either Lick Mill Blvd or the Guadalupe River Trail (west side). There is a north and south entrance off Lick Mill Blvd. The primary trail is a 0.75 mile loop that covers the interior of the park, with additional trails that meander through native gardens. On the northeastern and southeastern end of the park are wheelchair accessible ramps that lead up to the Guadalupe River Trail.
Springtime bloom at Ulistac, by Erica Fleniken
Signs of Restoration: Thanks to the work of Ulistac’s many volunteers, many native trees and plants have been planted over the last 20 years, including valley and coast live oaks, willows, cottonwoods, toyons, and sages. Eucalyptus trees still dominate the landscape and provide an established tree canopy that some migrants favor (e.g. Western Tanager). While there was originally discussion about whether the eucalyptus trees should all be removed to allow space for native trees, hundreds of native oaks have been found sprouting up in and around the eucalyptus with the help of birds like the Western Scrub Jay. In many areas where toyons were not planted by volunteers, a ring of young toyon shrubs encircle the base of mature eucalyptus, marking the locations where birds have sat digesting toyon berries and depositing the indigestible toyon seeds below.
Flannel Bush and Sages in Spring Bloom, by Erica Fleniken
Bird Survey Stations: The city of Santa Clara provided a $200,000 grant in 2015 to restore additional native habitat, and as part of the funding they requested a bird survey be conducted to help determine the success of the habitat restoration. There are six bird survey stations in the park in strategic locations, and volunteers conduct bi-monthly point count surveys to help document which species are present and how frequently they occur throughout the year (Note: surveys have been paused due to Covid-19). To date, 193 species have been reported by bird watchers and volunteers at Ulistac, and bird surveyors (as well as eBird users) have helped provide a detailed picture of nesting, migrant, and year-round patterns.
Sunset at Ulistac, by Erica Fleniken
Birding the Park: Bird activity is always highest in spring before 9 a.m., with peak activity depending on the weather (i.e. cloud cover, temperature, and winds). While there is no one way to bird the park, the eastern is often best in the early morning as the suns’ rays provide warmth from nighttime cooling. Later in the day, the western and more shaded side of the park begins to warm up, and the flocks tend to concentrate on the west side to avoid the heat. The levee trail along the Guadalupe River Trail is generally 10 degrees hotter than the interior trails in the park and bird activity is usually highest there in the earlier part of the morning.
One approach to looking for spring migrants involves doing one or more loops of the inner trail/s and listening for larger flocks. Virtually all the regular migrants favor the company of other birds and form mixed-species flocks. In the earlier part of the morning, migrants which have landed overnight will be spread out all over the park. As the morning goes on, these migrants tend to coalesce into groups, and finding these flocks usually results in seeing more species and more migrants. Another strategy involves patiently waiting at each bird survey station for 5 to 10 minutes to let birds become accustomed to your presence. The lack of movement and shuffling of the feet creates a stillness and silence that heightens auditory and visual acuity, making it easier to hear vocalizations and spot movement. Note, the survey stations are unsigned but are shown on the interactive map.
Some of the first migrants to arrive are Wilson’s Warbler and Rufous Hummingbird, with early arrivals in the last week of March. Wilson’s Warbler favors dense underbrush and can be detected by its dense, short, slightly descending chip, or by its staccato, accelerating song that rises to a crescendo. Rufous Hummingbird favors the yellow flowers of the tobacco tree by survey station 6 (see map); listen for their tails buzzing in flight like a noisy bee.
Rufous Hummingbird on Purple Majesty by Chris Johnson
Black-headed Grosbeak, Hooded Oriole, Bullock’s Oriole, Pacific-slope Flycatcher, and Cassin’s Vireo (uncommon) arrive in early April and may remain until the end of the breeding season (e.g. both orioles). Black-headed Grosbeak often skulks in deep cover but is readily detected by its loud, high-pitched, slightly rising, short metallic pik call, or by its rambling, slightly halting, fast-whistled song. Cassin’s Vireo (another skulker) can be detected by its persistent, short, two-note whistled phrases that have a rising and falling quality to them. The wide-billed Pacific-slope Flycatcher sings its rising two-note “suuu-weeet” from the middle of the forest canopy. Short and stocky Bullock’s Orioles chatter “kekekekeke” from the tops of eucalyptus, while long and slender Hooded Orioles give rising veep calls and snake-like rattles.
Bullock’s Oriole in a Willow by Erica Fleniken
Cassin’s Vireo in Valley Oak by Erica Flenikin
The next group of migrants arrive in early May (or the last week of April, more rarely), and include, Yellow Warbler, Black-throated Gray Warbler (uncommon), Nashville Warbler (uncommon), Hermit Warbler (rare), Warbling Vireo, Western Tanager, Lazuli Bunting (uncommon), Swainson’s Thrush, Western Wood Pewee, Olive-sided Flycatcher, and Hammond’s Flycatcher (rare).
Western Tanager in a Eucalyptus by Erica Fleniken
Yellow Warbler favors foraging high in the eucalyptus, and their large numbers at Ulistac make it a good place to learn their call (a long, mostly descending, whistled chip) or song (“sweet-sweet-little-more-sweet”). Black-throated Gray Warbler favors the oaks and willows and come through in fairly low numbers, but their soft, short, low chip (low for virens), is somewhat distinctive. Swainson’s Thrush’s sharp, short whit call or their upward-spiraling fluty melody is most often heard coming from dense underbrush, especially in the dense northern riparian area (see map).
Yellow Warbler near Station 2 by Chris Johnson
The rather common Western Wood Pewee sallies from open perches, often returning to the same snag near survey station 2, while the less common, mostly silent Olive-sided Flycatcher takes the highest perches in the center of the park (often in the company of Pewees). Warbling Vireo seldomly sings during migration and is often found in the company of other migrants, especially amongst oaks and willows, while the finch-like Lazuli Bunting favors open grassy or native garden areas (survey station 6).
Ready for More?
Stake out the small pond in the garden (see map) or the Guadalupe River opposite the north ramp when the temperatures rise and birds are coming for water. Walk south along the Guadalupe River Trail down to Montague Expressway or cross Lick Mill street and check out Lick Mill Park.
Follow our other self-guided field trip, Ulistac Natural Area (Fall).
In winter, White-throated Sparrow is found almost every year associating with crowned sparrows, and California Thrasher has bred in the park and is present year-round.
Interactive Map
On this map, the numbered pins indicate the bird survey stations and not a specific route. The unnumbered pins show the locations of other park features.
Directions: From CA-237 exit Great America Pkwy south, drive 0.8 miles, then turn left on Tasman Dr. In 1 mile turn right on Lick Mill Blvd and travel about 0.5 miles to the park, which will be on your left. Street parking. There are two park entrances on Lick Mill Blvd, one at the north end of the park and one at the south end of the park. Latitude/Longitude: 37.403418, -121.953984
Parking: On street parking along Lick Mill Blvd. When Levi stadium is in use, posted signs will note days when parking is not allowed; park along Lick Mill south of Hope Street.
Fees: None
Public Transportation: Short walk from the VTA Light Rail on Tasman Dr
Park Hours: Sunrise until one-half hour after sunset
Facilities: None. ADA compliant bathroom, benches and picnic tables are across the street in Lick Mill Park.
Mileage: A circuit of the area from the south entrance along the trail through the woods to the northern entrance and back along Lick Mill to your car is an easy, flat trail and under 2 miles. The interior trail loop is only 0.8 miles. Crisscrossing trails through the garden and walking along the Guadalupe River Trail will add mileage.
Trail Conditions/Accessibility: Trails are compacted dirt with some sections paved. They can be slippery or impassible after rain. Ramps to the Levee Regional Trail that runs alongside Guadalupe River are steep enough to make wheelchair use difficult without assistance. Forested areas offer some shade and crowding is minimal but will increase later in the day.
The south entrance provides access to the grasslands, butterfly and bird garden, and the southern ramp to the Guadalupe River. The north entrance is closest to the northern wetlands area, the oaks and woodlands, and the northern ramp to the River Trail.
Although there are no benches in this park, there are several logs to sit on if you need to rest. Stay on the trails - areas within Ulistac have Poison Oak.
Bikes: Bikes are allowed but not recommended for this trip
Dogs: Dogs are allowed on 6-ft leash
More Information
eBird hotspot: Ulistac Natural Area
Bird survey station map
More Resources
For more trips like this one, visit Self-Guided Field Trips.
Visit the SCVAS Birding Resources page for more information on where to bird, our birding community, bird identification resources and more.
Read “What to Look for Now” by SCVAS Executive Director Matthew Dodder.
Banner Photo Credit: Black-headed Grosbeak by Luis Villablanca
Last Updated: 5/23/2022
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