Urban coyotes in our midst

How the Golden Gate Bridge brought coyotes to San Francisco.

by on September 04, 2012

 
Photo by Janet Kessler.
 

 

Fabled as a wily shape-shifter and trickster, the coyote’s latest magic trick has been turning cities into habitat, and San Francisco is one of its latest acts.

Coyotes may have evolved in the plains and deserts of Mexico and North America, but they’ve rapidly expanded their range and are now making new homes for themselves in some of the largest urban centers, including Chicago, Vancouver, Los Angeles, and now San Francisco. San Francisco has seen a small but steady increase in the coyote population since they first appeared in the Presidio and Bernal Heights in 2001. Earlier this spring, coyote pups showed up in Golden Gate Park, sparking national attention and trail closures to protect the dens. San Francisco animal control estimates at least 15 individuals reside in city limits. Coyote hotspots include Twin Peaks, Lake Merced, Diamond Heights, Glen Park, Glen Canyon, Lands End, the Presidio, and Golden Gate Park.

“Coyotes are all over the city, in every neighborhood,” said San Francisco Animal Care and Control’s Lt.  Le-EllisBrown.

This is the first in a series of BayNature.org stories about our urban coyotes, where we’ll explore how Canis latrans got here and how it’s adapting to city life. Coyotes are hardly the first species to find suitable habitat among humans — raccoons, opossums, and bears also like to take advantage of all the waste we produce. But the San Francisco coyotes have a unique story to tell about how cities can be a bridge connecting rural populations. Quite literally a bridge, as it turns out.

Bridging the divide
In 2003, the Presidio Trust partnered up with Dr. Ben Sacks and Dr. Holly Ernest, from UC Davis’s School of Veterinary Medicine, and wildlife ecologist Dr. Erin Boydston of the US Geological Survey to learn more about the Presidio’s latest canine addition. Through radio-collaring and extracting the DNA from a coyote caught in the Presidio, these researchers found that the San Francisco coyotes originated from populations north of the Golden Gate Bridge, and not from the Peninsula, as one might assume. They must have crossed the Golden Gate Bridge to get there.

Photo by Janet Kessler.

California State University graduate student Katherine Marquez also found that San Francisco serves as a link between northern and southern populations, which historically have been genetically distinct. Marquez sampled a coyote in Lake Merced, on the southwestern edge of the city, that was related to the southern population, not the northern one. The genetic similarity in San Francisco’s urban coyotes also suggests that this population is rather insular, supporting theories that California coyotes aren’t too fond of leaving their natal habitat. Once a city coyote, always a city coyote.

Just how the northern coyotes got across the bridge leaves much to the imagination. Sacks and his group believed the coyotes came on their own, without hitching a ride with anyone. That idea was proven possible in 2004 when a coyote was spotted on videotape trotting across the Golden Gate Bridge.

Other methods of getting here seem unlikely. Coyotes are good swimmers, but they probably can’t make it across the treacherous currents of the San Francisco Bay. The only other land route would take a coyote over 250 km, circumventing the Bay-Delta Estuary and moving through the South Bay Hills population. Sacks and his group found it “especially unlikely” that coyotes utilized this jughandle approach to reach San Francisco.

The advance from the north is a bit surprising because historically the southern border has had the denser population. It wasn’t until coyotes began to recolonize Marin County, well after the Golden Gate Bridge was built in 1933, that they kept moving south, using the bridge as a highway of their own.

Coyote colonization

A handful of studies have begun to reveal how coyotes manage to live within urban landscapes, but it’s still unclear to scientists what prompts some coyotes to colonize cities while others remain on the periphery. Coyote specialist Stanley Gehrt, who directs the world’s longest-running urban coyote study in Cook County, Illinois, says that coyotes move into cities because of territorial pressure. Known as “land tenure,” older coyotes force out the youngsters who have yet to establish their own territory. When young coyotes leave their packs, usually after their first or second year, they embark on a journey to find vacant habitat to claim as their own.

In a phenomenon similar to sprawl, as coyote populations thrive, more and more young coyotes venture off in search of available territory, leading them into unoccupied suburbs and cities.

Photo by Janet Kessler.

Since they’re a generalist species, capable of adapting their diet and lifestyle to a range of environments, coyotes can call any place home, even if it’s concrete. However, urban coyotes are still wild and prefer more natural areas, sticking to woodlots, canyons, open parks, and golf courses, and choose to avoid people and their residential and commercial areas.

It seems that the Golden Gate Bridge has upheld San Francisco’s reputation as an open and green city, connecting habitat and helping to spread the gene-flow love from north to south, rather than fragmenting wildlife populations like so many man-made structures do.

This is the first in a BayNature.org series on urban coyotes. Come back next week for Part 2: Survival 101 for the urban coyote.

Courtney Quirin is a Bay Nature editorial intern who has studied urban coyotes extensively in a graduate degree program. 

 

Nature news junkie? Get our weekly news digest!

 

14 comments:

david on September 5th, 2012 at 6:57 am

excellent article!

anna on September 14th, 2012 at 10:47 pm

Great article. Just encountered one at 40th/Clement when walking the dog this afternoon. Just kept our distance from each other and it went trotting off down the golf course.

Vikram on September 19th, 2012 at 1:12 pm

great work! coyotes rock!

Melissa on September 19th, 2012 at 3:20 pm

I was hiking Fremont near Mission Peak and I encountered one just 10 ft in front of me. I have a picture on my blog. I thought it was so neat to see one. I’ve never seen one while hiking. It was awesome.

http://chasquimom.blogspot.com/2012/09/another-way-to-mission-peak.html#more

JYS on September 29th, 2012 at 8:11 am

A great article! Can you write about wild turkeys in the next series? My kids would love to read more about the flocks that live in our Lafayette neighborhood.

Dan Rademacher on October 1st, 2012 at 10:16 am

We did a piece on wild turkeys a while back. The piece is half pigs, half turkeys, actually. Check it out here: http://baynature.org/articles/ground-invasion/

L. A. on November 12th, 2012 at 12:07 am

Coyotes are gorgeous creatures. That said, if they are thriving and multiplying – unchecked – they could be having a harmful effect on other wildlife populations in Golden Gate Park.

Jack Henderson on November 21st, 2012 at 12:59 pm

We have a coyote that we have twice seen touring around in our back yard in Glen Park. We also have a lot more red tails cruising around and a burgeoning rook population. It’s a zoo out there in San Francisco!

Brad on December 16th, 2012 at 11:40 am

Saw a young grey coyote last evening at Masonic/Upper Terrace. Was worried a car might hit it. Are we supposed to report these to Animal Care? Or do we accept them as part of our diverse population?

Alison Hawkes on December 17th, 2012 at 9:41 am

Good question! I’m guessing that unless it’s been injured or is causing trouble, you would leave it alone. But if you’re worried about it, definitely call Animal Care & Control. Seems like it may be living in Cornona Heights or Buena Vista.

mike on January 5th, 2013 at 8:06 pm

Saw one last night
Christopher street near Clarindon
Twin Peaks

Dan Rademacher on January 6th, 2013 at 1:06 pm

Cool! Thanks for letting us know!

Gina on February 5th, 2013 at 10:47 am

Beware…they are growing & not finding enough food in the canyon. They are venturing into our neighborhoods & eating our cats and dogs. They need to be relocated!!!

Jaymi on July 11th, 2013 at 12:01 pm

Gina — no they’re not. And relocating is *not* an answer.

First, coyotes far prefer fruits, veggies, rodents and mesopredators like raccoons and skunks to pets. Having coyotes around — an apex predator — just shows that we have a really healthy ecosystem. Their presence is a good sign that things are functioning and staying balanced. Sure, some coyotes will snatch up the random small dog or cat, but that’s not typically their preferred food source — not by a long shot.

Second, coyotes are territorial. If you try to relocate them, the result is that the relocated coyote is hurt or killed either by the coyotes that rule the territory they’re relocated into, or they are killed by cars trying to get back to their own turf or find a new empty territory. You’re actually harming a coyote by relocating it. Meanwhile, the space the relocated coyote just left has a giant “FOR RENT” sign on it and other coyotes move in. Because they are territorial, coyotes do their own population regulation, so the best way to keep coyote populations minimized is to just leave them alone. And the best way to coexist is to limit your interaction with them. Keep your dogs on leash and your cats inside, and scare off any coyotes you encounter so they maintain their fear of humans, and you’re fine.

Leave a Comment

Name

Email

Website

Comment

 
 
Fall 2014 Reader Survey