One Watershed, Many Worlds—How Wildlife Shifts Across Coyote Creek’s Parks

When I first started my internship with Keep Coyote Creek Beautiful, one question kept pulling at me: How can one watershed support so many different kinds of life? Coyote Creek winds through neighborhoods, forests, and foothills—linking places like Hellyer County Park, Alum Rock Park, and even stretches near Malaguerra Avenue in Morgan Hill. And yet, the species I encounter in each place feel completely different.

I’ve been especially curious about how biodiversity shifts along the creek, and what that says about the ecosystems we’re working to protect. So I started doing something simple but eye-opening: paying closer attention. I compared my observations across parks, uploaded them to iNaturalist, and slowly, patterns began to emerge.

At Hellyer County Park, biodiversity feels active and social. Birds like the Black Phoebe (Sayornis nigricans) hover over ponds, Red-winged Blackbirds (Agelaius phoeniceus) call from the cattails, and Western Fence Lizards (Sceloporus occidentalis) bask openly on sunny rocks. I even spotted non-native Red-Eared Sliders (Trachemys scripta elegans) hauled out along Cottonwood Lake, a reminder of how urban introductions shape creek life. Hellyer’s mix of riparian trees like willows and cottonwoods alongside disturbed areas dominated by invasive grasses creates habitat for generalist species—from European Starlings (Sturnus vulgaris) to Gray squirrels (Sciurus carolinensis). It’s a place where adaptability is key, and it shows how wildlife finds ways to thrive in highly visited public parks.

           Black Phoebe Red-Eared Sliders Western Fence Lizards

(Sayornis nigricans) (Trachemys scripta elegans)  (Sceloporus occidentalis)

Black Phoebe (Sayornis nigricans)

Photos by Merav Vonshak

Further south at the Coyote Creek Visitor Center at Malaguerra Avenue, the creek takes on a quieter, more transitional role. This stretch near Morgan Hill is less developed, and because of that, I noticed a stronger presence of riparian plants like Valley Oak (Quercus lobata) and Mulefat (Baccharis salicifolia). Bird life included species that depend on these habitats, like the Yellow-Rumped Warbler (Setophaga coronata) moving through branches, and Snowy Egrets (Egretta thula) patrolling the shallows. iNaturalist records from this area also highlight the presence of native amphibians like California Newts (Taricha torosa), which rely on clean seasonal streams to breed. What stood out to me was how this area functions as a connective zone—wildlife can move through without as much human disturbance, making it an important link in the larger watershed corridor.

Snowy Egrets Yellow-Rumped Warbler

(Egretta thula)  (Setophaga coronata)

Then there’s Alum Rock Park, where biodiversity reveals itself in strange and beautiful details. This is where I first noticed galls—those round growths on oak leaves caused by Gall Wasps (Cynipidae). They’re tiny, but they represent a whole food web: parasitic wasps laying eggs inside them, birds feeding on the larvae, and oaks sustaining the entire process. I also came across Spittlebugs (Cercopoidea), hiding in their protective foam along plant stems, and noticed the stark competition between invasive Argentine Ants (Linepithema humile) and native American Winter Ants (Prenolepis imparis), which cleverly avoid direct conflict by foraging in colder conditions. Alum Rock’s shaded canyons and oak woodlands make it one of the richest insect habitats I’ve seen, and it’s no surprise that Acorn Woodpeckers (Melanerpes formicivorus) thrive here, drilling granaries into trees and attracting insect prey along the way.

Gall Wasps Spittlebugs Argentine Ants Native Winter Ants

(Cynipidae) (Cercopoidea) (Linepithema humile) (Prenolepis imparis)

Further upstream, research into Anderson Lake County Park shows another facet of the Coyote Creek watershed’s biodiversity. Although I haven’t personally explored this area yet, iNaturalist observations indicate a thriving oak-chaparral ecosystem. Species like California scrub-jays (Aphelocoma californica), Acorn Woodpeckers (Melanerpes formicivorus), and Red-Tailed Hawks (Buteo jamaicensis) patrol the skies, while Mule deer (Odocoileus hemionus) and Brush Rabbits (Sylvilagus bachmani) move quietly on the ground. The park’s seasonal wetlands support amphibians such as California newts (Taricha torosa), and reptile sightings include Western Fence Lizards (Sceloporus occidentalis) and Gopher Snakes (Pituophis catenifer). Its oak woodlands, chamise, and native grasses create a habitat that is both drought-tolerant and rich in species interactions. This makes Anderson Lake an important area for understanding how the watershed supports both terrestrial and aquatic life, and it highlights the potential for exploration and citizen science contributions through platforms like iNaturalist.

California scrub-jays | Acorn Woodpeckers | Red-Tailed Hawks

(Aphelocoma californica) (Melanerpes formicivorus) (Buteo jamaicensis)

Mule deer Brush Rabbits  

(Odocoileus hemionus)  (Sylvilagus bachmani) 

California newts | Western Fence Lizards | Gopher Snakes

(Taricha torosa) | (Sceloporus occidentalis) | (Pituophis catenifer)

Each of these discoveries taught me something new. I’m starting to understand how different landscapes shape different lives. I’m learning to notice microhabitats, behavioral patterns, and seasonal shifts. And thanks to iNaturalist, I’m not just observing—I’m participating. Each photo I upload becomes part of a shared record of life across our watershed, helping scientists, community members, and fellow nature-lovers track how biodiversity is changing over time.

What’s most surprising is that even parks only a few miles apart can diverge completely in their ecology. From the generalist birds at Hellyer to the amphibian-rich streams near Malaguerra, to the intricate oak-insect webs of Alum Rock, and the chaparral-connected wildlife at Anderson Lake, each location tells a distinct ecological story—one that couldn’t exist without the specific terrain, plant life, and climate that shape it.

I used to walk through these parks without really seeing. Now I see layers of interactions, adaptation, competition, and care. This internship is still in its early stages for me, but I already feel like I’ve been given a key to a deeper kind of knowledge. Biodiversity isn’t just something you find—it’s something you come to understand, one species at a time. And the best part? Anyone can start learning, simply by stepping outside, looking closely, and maybe even logging your own discoveries on iNaturalist.