by Ranger Ginger Gonzalez 

Did you know we have otters right here in Sycamore Grove Park?  I personally have yet to see one, but park patrons who quietly linger around the water say they’ve seen them plenty. These carnivorous mammals are usually seen playing in the water and wrestling one another WWE style. They are cute critters and naturally very curious, often swimming up to kayaks and shores to see what all the commotion is!   

Local Otter Populations on the Rise 

I was delighted to learn there’s been a recent boom in otter populations inhabiting the water and creek banks that run along the Arroyo del Valle! But why? Our North American river otters are more than cute, water weasel-like beings in Sycamore Grove Park—they’re a big sign that things are on the up & up! Plus, the otters aren’t just enjoying the improved habitat; they’re actually making it even better for more critters! 

This recovery is linked to stricter water quality regulations, habitat restoration, and reintroduction programs throughout California’s watersheds. Because otters sit high on the food web and rely on clean water and abundant prey, their regular presence signals good water quality, intact riparian habitat, and balanced fish and invertebrate populations. Yay for habitat restoration and cleaner streams!  

Nom Noms 

Otters primarily eat fish and crayfish but also consume amphibians and, at times, waterbirds. By preying on the most available or vulnerable individuals—often including sick or parasite-laden prey—they help prevent boom-and-bust cycles and can reduce pressures from invasive species like common carp and nonnative crayfish, supporting more stable, diverse aquatic communities. 

Their hunting and movement connect stream pools, side channels, and nearby ponds (including spots that link to vineyard water features), distributing nutrients and influencing where fish and invertebrates congregate. This creates a mosaic of microhabitats along the creek that benefits turtles, native fishes, dragonflies, and riparian plants. 

Healthy otter populations encourage attention to riparian buffers, shaded banks, and connected wetlands—features that also filter pollutants, reduce erosion, and improve drought resilience for the entire Arroyo del Valle corridor. Success stories elsewhere show that when wetlands and water quality are restored, otters rebound—and so does overall watershed health. 

Observing Otters in the Park 

So, my dear readers, get outside more and explore; you never know what you'll see! Now if you’re fortunate enough to run into an otter in Sycamore Grove Park, please remember:  

1. Tell them thanks for all their hard work.  

2. Admire them from afar!!   

3. Please do not disturb them or their habitat.  

4. Do remember all rules we enforce in the park are to keep you and our wild critters safe, so we appreciate cooperation from the community.  

5. Thank you, on behalf of all our wildlife that call Sycamore Grove home!  

Editor’s Note: 

Want to contribute to the recovery of river otters?  Seen an otter at Sycamore Grove Park or elsewhere?  Become an Otter Spotter!  By submitting your otter sighting, you will help grow a database of how these charismatic creatures are doing across North America, informing conservation efforts now and in the future.  Learn more at https://riverotterecology.org/become-an-otter-spotter/

Read more Open Space ranger articles here:  Valley Wilds Newsletter & Article Archive - Livermore Area Recreation and Park District