Newsletter - September 2025
Wild Birds Unlimited - San Diego Events:
September Events:
In-Store Guest Presentation: September 20th at 10:00 AM. Wildlife Research Institute (WRI) Research Director and host of the Hawk Watch program in Ramona, Katie Quint, will provide the audience with information on the historical significance and current status of Bald and Golden Eagles in San Diego County.
As a local non-profit out of Julian, CA, WRI is known for its long-term commitment to documenting the incredibly interesting dynamics of reproductive activity, territory and nest distribution, and flight patterns of San Diego County's Golden Eagles.
Telemetry flight path maps and photographic results of WRI's recent aerial helicopter surveys and monitoring program will be on display to demonstrate how incredible the Golden Eagle is as a species.
You will walk away from this presentation with a profound appreciation for San Diego's native nesting eagle along with the research and advocacy work being conducted in order to protect them locally.
Quote of the Month:
Birds chirping around you is a beautiful realization that life is incredibly good. Let this sound be a gentle break in your routine – Hiral Nagda Spotlight:
Spotlight: Initiative for Helping a Bird in Steep Decline ... Can you guess this bird?
- It is increasingly rare (imperiled across its range in coastal Southern California)
- It builds several tubular nests in an area. Unlike other birds, it uses these nests as shelters year-round
- It sounds like a car trying to start!
- It is especially attracted to areas with elderberry
- It won’t explore more than a mile from its birthplace over its lifetime (with rare exceptions)
 It’s Campylorhynchus brunneicapillus sandiegensis*, which means San Diego curved-bill brown-head, also known as the coastal cactus wren!   Appearance
The coastal cactus wren is:
- a large, chunky wren with long, curved bill and short, rounded wings
- about the size of a robin, with:
- tail ending in a rounded wedge, decorated in black & white bars, which are apparent from below
- brown head and brown back heavily streaked in white
- black speckles on a pale chest, with cinnamon sides
- bright white eyebrow
Similar-looking species with different coloration are sage thrashers, canyon wrens, and rock wrens
Range
The coastal cactus wren (C. b. sandiegensis), our own genetically distinct subspecies, has a very limited range, extending from extreme northwestern Baja California (Valle de las Palmas) through the coastal lowlands of San Diego County and into southern Orange County.
Diet and Habitat
Cactus wrens forage on the ground and among the plants of coastal sage scrub, often in pairs or family groups, probing in bark crevices and leaf litter. They consume insects (beetles, ants, wasps, grasshoppers, a few spiders, and many other bugs), some fruits and seeds (~20% of diet), and occasional small lizards.
However, 80% of San Diego’s coastal sage scrub habitat has been lost to development since the 1970’s. You can help nature by adding sage scrub plants to your property, such as California sagebrush (Artemisia californica), blue elderberry (Sambucus nigra subspecies caerulea), buckwheat (Eriogonum species, of which arborescens and cinereum are especially nice in gardens), Ceanothus species (locally known as California or Ramona lilac), monkeyflower (Diplacus or Mimulus aurantiacus, or puniceus for moister, shadier spots), toyon (Heteromeles arbutifolia), black sage (Salvia mellifera), white sage (Salvia apiana), native currants (Ribes divericatum), brittlebush (Encelia californica), California aster (Corethrogyne filaginifolia), Menzies' goldenbush (Isocoma menziesii), and coyote brush (Baccharus species, which tend to spread). See calscape.org for great plant information and nursery availability.
Cactus wrens require dense masses of mature, sharp-spined cactus for nesting. The prickly cacti form an impenetrable fortress to protect nests against predation. Overhanging trees and shrubs are a risk, because they allow snakes and other predators to drop onto the nests.
In the San Diego area, the two main cacti used by coastal cactus wrens are Opuntia littoralis (coast prickly-pear; below, left), with yellow or peach colored blooms, and Cylindropuntia prolifera (coastal cholla; below, right), a showy many-branched plant with pink blooms and pinkish spines. Both are easily propagated from segments and best handled with tongs! These cacti are great for fire-repellent landscaping (like water balloons) but they don’t tend to survive fire, leading to habitat loss for the wrens. Optimal cactus wren habitat is cactus/coastal sage scrub in low foothills with southern or western exposure.  Coast prickly-pear and Coastal cholla  Optimal cactus/sage scrub for coastal cactus wrens in the San Pasqual Valley Getting around
Cactus wrens are not strong flyers, which may account for their limited exploring (about 1 mi from their birthplace). They require high-quality stepping stones of habitat (coastal sage scrub + mature, dense spiny cacti) spaced no more than a mile apart. Otherwise, cactus wrens will not find new territory following fires or development that disrupts their habitat corridors. When the population declines and they are separated from other cactus wrens, they become inbred and produce fewer healthy chicks.
Genetics, population trends and habitat restoration
Genetic sampling of coastal cactus wrens at their four San Diego County hotspots — San Pasqual Valley and Lake Hodges, Sweetwater, Lake Jennings, and Otay — identified 125 unique family groups and showed that the wrens are genetically distinct between these sites (Vandergast, Kus, and Smith, 2022). Another conclusion is that the San Pasqual/Lake Hodges cactus wrens have lost much of their genetic diversity and “at currently estimated effective sizes, populations of cactus wrens will continue to lose genetic diversity for many generations, even if gene flow among them is enhanced. However, the rate of loss of heterozygosity [genetic diversity] could be reduced with increased gene flow. Habitat restoration may help bolster local population sizes and [genetic diversity] over the long term”.
As a result, much work is being done to create cactus wren habitat and link habitats by creating prickly-pear cactus nurseries and planting prickly-pear colonies adjacent to coastal sage scrub in the San Pasqual Valley, Highland Valley, and Lake Hodges area. The Cactus Wren Initiative is working on building stepping stones of cactus habitat in the coastal sage scrub of the Black Mountain area, where there have been increasing cactus wren sightings in the last few years.
Threats
Cactus wrens’ main threats are habitat loss and fragmentation, wildfire, vehicle collisions, predation while foraging (outdoor and feral cats may be an issue), and noisy human/bicycle/dog activity on trails near their nests.
How you can help (and it’s even fun 😊) … The Cactus Wren Initiative!
The Cactus Wren Initiative asks birders to hone their cactus wren ID skills and actively report wren or nest sightings (supported by photos or audio recordings) on iNaturalist or eBird. Your data will better define paths the cactus wrens are exploring between sites, and guide our placement of new cactus habitat where it is safest and most useful. Then cactus wren individuals can better intermix with others in Lusardi Creek, Black Mountain Ranch, Lake Hodges, Highland Valley, and San Pasqual Valley, increasing their genetic diversity, population size, and health. Particularly needed is more monitoring/sighting of cactus wren presence south of Lake Hodges and west of Interstate 15, up to the convergence between Lusardi Creek and San Dieguito River west of Lake Hodges. See the associated announcement and map in this newsletter.  Thank you! You can make a difference for the coastal cactus wrens!
- Dr. Leslie Kuhn, The Cactus Wren Initiative
References:
Bird icon: ChatGPT, Creative Commons CC0 1.0 Universal Public Domain Dedication
Song: https://xeno-canto.org/species/campylorhynchus-brunneicapillus
Identification: https://www.allaboutbirds.org/guide/Cactus_Wren/id
Photos: by Leslie Kuhn, with cactus wren photo by Alan Vernon (Flickr: Cactus Wren (Campylorhynchus brunneicapillus), CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=14693457)
Distribution/rarity: Rea & Weaver (1990):
https://sdmmp.com/view_article.php?cid=SDMMP_CID_230_5efa2aa11642e
San Diego Zoo habitat conservation of coastal cactus wrens: https://science.sandiegozoo.org/science-blog/helping-locally-imperiled-coastal-cactus-wren
Diet: https://www.audubon.org/field-guide/bird/cactus-wren
Regional conservation effort: Coastal Cactus Wren Conservation Network of the San Diego Management and Monitoring Program: https://sdmmp.com/view_project.phpsdid=SDMMP_SDID_187_5cdc42487f4be
San Diego County Cactus Wren Hotspots, Population Trends, and Genetics:
Amy G. Vandergast , Barbara E. Kus, and Julia G. Smith (2022): https://doi.org/10.1111/csp2.12780
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Bird of the Month: California Scrub-Jay
California Scrub-Jay Scripps Ranch, California
California Scrub-Jay
Appearance & Identification
- Bright blue & gray: A vivid blue head, wings, and tail, with a soft grayish back and whitish underparts. A distinct blue necklace crosses its breast, and a white eyebrow stripe gives it an alert, expressive look.
- Not a “blue” bird at all: Their feathers don’t contain any blue pigment. Instead, microscopic feather structures scatter light to create the color blue (structural coloration).
- Crest-free head: Unlike their Blue Jay cousins, scrub-jays lack a head crest, making them appear sleek and smooth.
- Size metrics: About 11–12 inches long with a 15-inch wingspan, weighing around 80 grams—larger than most backyard songbirds.
Range & Habitat
- Found from southern British Columbia through California to Baja, they’re year-round residents in San Diego.
- Thrive in oak woodlands, chaparral, scrublands, riparian zones, backyards, and parks.
- Non-migratory, so if you see a scrub-jay in your yard, chances are it lives nearby all year.
Diet & Feeding Behavior
- Omnivores: Eat a wide variety—acorns, pine nuts, sunflower seeds, insects, fruits, small reptiles, and occasionally even bird eggs or nestlings.
- Backyard visitors: Love sunflower seeds and peanuts—especially unsalted, in-shell peanuts. They’ll inspect and pick the biggest one first, sometimes testing several before choosing!
- Ecological allies: Famous for caching acorns in the ground; many forgotten ones sprout into oak trees, helping regenerate local woodlands.
- Acorn specialists: Their throat and esophagus can temporarily store multiple acorns at once, allowing them to carry several to bury.
- Peanut perfectionists: Known to select peanuts by size, always picking the biggest first.
- Deer companions: Sometimes perch on mule deer and pick off ticks—offering grooming in exchange for a snack.
Intelligence & Social Behavior
- Corvid cognition: With brain-to-body ratios rivaling primates and dolphins, scrub-jays are among the smartest birds in the world.
- Memory masters: Can recall hundreds of food cache locations, how long ago they were stored, and whether they contained perishable or long-lasting food.
- Future planners: Experiments show they plan for tomorrow—stashing food in spots where they know they’ll be hungry the next morning.
- Cache tricksters: If they think another jay is watching, they’ll pretend to hide food in one spot, then secretly move it elsewhere—or even plant fake “decoys” like pebbles!
- Neighborhood “watchdogs”: Their loud calls often alert other birds—and people—to predators. Many birders say, “If you hear scrub-jays screaming, look for a hawk.”
- Social ceremonies: When a scrub-jay dies, others gather and call loudly for up to 30 minutes. These “funerals” may serve to alert others of danger.
Sounds & Communication
- Varied calls: Harsh “shreeeek” alarms, raspy “zhree” notes, and chatter.
- Mimics: Sometimes imitate hawk calls—possibly to warn others or to scare competitors away from food.
- Fearless defenders: Will boldly mob and harass hawks many times their size, swooping and calling until the predator leaves.
Nesting & Reproduction
- Build sturdy cup nests from twigs, moss, and grass, lined with hair and softer fibers.
- Nests are placed low in shrubs or small trees, usually 4–15 feet off the ground.
- Clutches contain 1–5 pale greenish eggs; females incubate for ~18 days, and young fledge about 18 days later.
- Both parents share feeding duties once chicks hatch.
Backyard Encounters
- Feeder boldness: They’re assertive, often chasing away smaller birds.
- Tame personalities: In urban neighborhoods, some scrub-jays become so accustomed to people they’ll take peanuts from your hand.
- Youthful antics: Juveniles sometimes “beg” at feeders, wing-fluttering like they would to parents.
Lifespan & Records
- Typical lifespan in the wild: 9 years.
- Longest known wild bird: 15 years, 9 months.
- In captivity, one bird lived nearly 20 years!
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What’s happening in San Diego:
Please note: This information is compiled by hand and mistakes or changes are possible. Please be sure to confirm dates/times/locations on the pages linked before leaving for an event.
San Diego Bird Alliance (formerly San Diego Audubon Society)
- Outing Leader Orientation
- Date: September 4, 2025
- Time: 6:30 PM – 8:30 PM
- Location: Zoom
- Event Link
- River Mouth Restoration
- Date: September 5, 2025
- Time: 9:00 AM – 1:00 PM
- Location: Ocean Beach – Dog Beach, 5156 W Point Loma Blvd, San Diego
- Event Link
- Go Birding for California Biodiversity Day
- Date: September 6-14, 2025
- Time: That’s up to you
- Location: That’s up to you too
- Event Link
- San Diego Pelagic Trips (Proceeds benefit Buena Vista Audubon Society)
- Dates: September 6, 7 and 27, 2025
- Time: 7:00 AM – 6:00 PM
- Location: 1717 Quivira Road, San Diego (double check)
- Event Link
- Queer Hike: Tecolote Canyon Natural Park
- Date: September 11, 2025
- Time: 8:00 AM – 11:00 AM
- Location: TBD Tecolote Canyon, San Diego
- Event Link
- Birding for Beginners Fall 2025
- Date: Starting September 11, 2025 (6-week class)
- Times: See Event Link
- Location: Zoom and multiple field trip locations
- Event Link
- Monthly Morning Chorus
- Dates: September 13, 2025
- Time: 7:30 AM – 9:00 AM
- Location: Anstine Audubon Preserve, 2437 Hutchison St., Vista
- Event Link
- Latino Conservation Week: Wander the Wetlands (Bilingual)
- Dates: September 13, 2025
- Time: 9:00 AM – 1:00 PM
- Location: 2055 Pacific Beach Dr, San Diego
- Event Link
- Friends of Famosa Slough Work Party
- Date: September 13, 2025
- Time: 9:00 AM to 12:00 PM
- Location: 4285 W. Pt. Loma Blvd, San Diego
- Event Link
- Bird Walk with Torrey Pines Conservancy
- Date: September 15, 2025
- Time: 10:00 AM -12:00 PM
- Location: Torrey Pines Reserve Lodge & Visitor Center, 12600 N Torrey Pines Road, La Jolla
- Event Link
- LCW-CLTE Vegetation Monitoring & Restoration Event! Bilingual
- Date: September 16, 2025
- Time: 9:00 AM -12:00 PM
- Location: Mariner's Point, San Diego
- Event Link
- Rose Creek Habitat Restoration
- Date: September 19, 2025
- Time: 9:00 AM -12:00 PM
- Location: Rose Creek Cottage 1900, 2525 Garnet Ave, San Diego
- Event Link
- Bird Outings: Famosa Slough
- Date: September 20, 2025
- Time: 9:00 AM – 11:00 AM
- Location: 4285 W. Pt. Loma Blvd, San Diego
- Event Link
- LCW – Journey Through the Wetlands
- Date: September 21, 2025
- Time: 9:00 AM – 2:00 PM
- Location: Tijuana Estuary Visitor Center
- Event Link
- Birding by Ear: Lake Murray
- Date: September 21, 2025
- Time: 9:00 AM – 11:00 AM
- Location: Lake Murray - Boat Dock, 5540 Kiowa Dr., La Mesa
- Event Link
- Game Night: Wingspan
- Date: September 25, 2025
- Time: 6:30 PM – 8:00 PM
- Location: REI Recreation Room 5556 Copley Dr., San Diego
- Event Link
- Famosa Slough Habitat Restoration and Maintenance
- Date: September 26, 2025
- Time: 9:00 AM – 12:00 PM
- Location: Famosa Slough, 2551-2599 Famosa Blvd, San Diego
- Event Link
- Wander the Wetlands: Work Party
- Date: September 27, 2025
- Time: 9:00 AM – 11:00 AM
- Location: 2055 Pacific Beach Dr, San Diego
- Event Link
Palomar Audubon Society
- Santee Lakes Field Trip
- Date: September 6, 2025
- Time: 8:00 AM – 11:30 AM
- Location: Santee Lakes Recreational Preserve 9310 Fanita Parkway, Santee
- Event Link
Buena Vista Audubon Society
- Rancho Carrillo Trail
- Date: September 5, 2025
- Time: 7:30 AM – 8:30 AM
- Location: Rancho Carrillo Trail, Carlsbad
- Event Link
- Whelan Lake Bird Sanctuary Walk
- Date: September 6, 2025
- Time: 8:00 AM – 10:00 AM
- Location: Whelan Lake, 3650 North River Road, Oceanside
- Event Link
- Oceanside Plein Air Festival - Workshop
- Date: September 7, 2025
- Time: 9:30 AM – 12:30 PM
- Location: Buena Vista Nature Center,2202 South Coast Hwy., Oceanside
- Event Link
- El Corazon Garrison Creek (Oceanside)
- Date: September 10, 2025
- Time: 7:30 AM – 9:00 AM
- Location: El Corazon Park, 3210 Oceanside Blvd, Oceanside
- Event Link
- Kids’ Nature Clubhouse and Trail Exploration
- Date: September 14, 2025
- Time: 11:00 AM – 12:30 PM
- Location: Buena Vista Nature Center,2202 South Coast Hwy., Oceanside
- Event Link
- Virtual Program: Tools of the Trade: Avian Bill Adaptations
- Date: September 17, 2025
- Time: 7:00 PM – 9:00 PM
- Location: Zoom
- Event Link
- Birding with Barbara
- Date: September 20, 2025
- Time: 8:00 AM – 10:00 AM
- Location: Buddy Todd Park, parking lot near the restrooms at 2800 Mesa Drive, Oceanside
- Event Link
- Nature Journaling
- Date: September 21, 2025
- Time: 1:30 PM – 3:30 PM
- Location: Jack’s Pond Park, 986 La Moree Rd, San Marcos
- Event Link
- Preschool Nature Storytime at the Nature Center
- Date: September 22, 2025
- Time: 10:00 AM – 10:45 AM
- Location: Buena Vista Nature Center,2202 South Coast Hwy., Oceanside
- Event Link
- Buena Vista Creek Restoration Workshop
- Date: September 23, 2025
- Time: 5:30 PM – 7:00 PM
- Location: Salvation Army, 3935 Lake Blvd, Oceanside
- Event Link
- Coastal 101 Birding (Oceanside)
- Date: September 27, 2025
- Time: 9:00 AM – 10:00 AM
- Location: Buena Vista Nature Center,2202 South Coast Hwy., Oceanside
- Event Link
San Diego Botanical Gardens
- Bird Walk
- Date: September 10, 2025
- Time: 8:00 AM
- Location: San Diego Botanical Gardens, 300 Quail Gardens Dr., Encinitas
- Event Link
- Butterfly Walk
- Dates: September 8 and 22, 2025
- Time: 10:00 AM
- Location: San Diego Botanical Gardens, 300 Quail Gardens Dr., Encinitas
- Event Link
San Dieguito River Valley Conservancy
- Creekside Critters with Jeff Nordland
- Date: September 6, 2025
- Time: 11:00 AM – 12:00 PM
- Location: Del Mar Branch Library, 1309 Camino Del Mar, Del Mar
- Event Link
- Yoga at the Birdwing
- Dates: September 7, 13 and 21, 2025
- Time: 10:00 AM – 11:00 AM
- Location: Birdwing Open Air Classroom, 15737 San Andres Dr, Del Mar
- Event Link
- Fall Trails and Ales
- Date: September 9, 2025
- Time: 4:00 PM – 7:30 PM
- Location: San Dieguito Lagoon Staging Area, 15648 San Andres Drive, Del Mar
- Event Link
- SDRVC Monthly Walk N Talk
- Date: September 26, 2025
- Time: 9:00 AM – 12:00 PM
- Location: Arroyo Preserve, 17261 El Vuelo, San Diego
- Event Link
- Gonzalez Canyon Habitat Restoration
- Date: September 27, 2025
- Time: 9:00 AM – 11:00 AM
- Location: 13655 Sword Way, 13655 Sword Way, San Diego
- Event Link
San Elijo Lagoon Nature Collective
- Discovery Tour
- Date: September 6, 2025
- Time: 10:00 AM – 11:30 AM
- Location: San Elijo Lagoon, Nature Center Loop Trail, 2710 Manchester Ave., Cardiff-by-the-Sea
- Event Link
- Wildlife Tour
- Date: September 13, 2025
- Time: 8:30 AM – 10:30 AM
- Location: San Elijo Lagoon (location will be emailed)
- Event Link
Living Coast Discovery Center
- Bilingual Sweetwater Safari Hike
- Date: September 6, 2025
- Time: 11:30 AM – 12:00 PM
- Location: Living Coast Discovery Center, 1000 Gunpowder Point Drive, Chula Vista
- Event Link
- Sweetwater Safari Hike
Tijuana Estuary
- Nature Walk: An Eye-Opening Experience Without Sight
- Date: September 6, 2025
- Time: 11:00 AM – 12:00 PM
- Location: Tijuana Estuary Visitor Center, 301 Caspian Wy, Imperial Beach
- Event Link
- Bird Walk
- Dates: September 7, and 21, 2025
- Time: 10:00 AM – 11:00 AM
- Location: Tijuana Estuary Visitor Center, 301 Caspian Wy, Imperial Beach
- Event Link
- Nature Walk
- Date: September 13, 2025
- Time: 11:00 AM – 12:30 PM
- Location: 5th Street & Iris Avenue, 5th St & Iris Ave, Imperial Beach
- Event Link
- Bilingual Bug Hike at Tijuana Estuary
- Date: September 14, 2025
- Time: 9:00 AM – 11:00 AM
- Location: Tijuana Estuary Visitor Center, 301 Caspian Wy, Imperial Beach
- Event Link
- Coastal Cleanup Day
- Date: September 20, 2025
- Time: 9:00 AM – 12:00 PM
- Location: Multiple Locations – see link for details
- Event Link
- Bilingual Clean-up at the Marina View Park
- Date: September 20, 2025
- Time: 9:00 AM – 11:00 AM
- Location: Marina View Park, 900 Marina Pkwy, Chula Vista
- Event Link
- Nature Book Club
- Date: September 27, 2025
- Time: 10:00 AM - 11:30 AM
- Location: Tijuana Estuary Visitor Center, 301 Caspian Wy, Imperial Beach
- Event Link
- Canyoneer Hike: Tijuana River Valley Regional Park (Dairy Mart Trailhead)
- Date: September 27, 2025
- Time: 8:00 AM - 10:30 AM
- Location: See event link for directions
- Event Link
- Summer Storytime
- Date: September 27, 2025
- Time: 10:00 AM - 11:00 AM
- Location: Tijuana Estuary Visitor Center, 301 Caspian Wy, Imperial Beach
- Event Link
- Nature Walk
- Dates: September 27, 2025
- Time: 11:00 AM – 12:00 PM
- Location: Tijuana Estuary Visitor Center, 301 Caspian Wy, Imperial Beach
- Event Link
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