Subject: REPORT: Gray Fox Report for June 2018


Our vision is a San Francisco Bay Area Wildlife Corridor. UWRP notes that as Silicon Valley’s human population, development, and sea level increases, it is of utmost importance that the wildlife thoroughfares are identified and protected, thus maintaining California’s natural genetic diversity.

Since there are no gray foxes at the Palo Alto Baylands Nature Preserve, and I don’t expect any to make it their home range until possibly late November through early January 2019. As such I will continue substituting varied information about select events and the wildlife that make the baylands their home.

Over the past several months a red fox has shown up before our trail cameras. Since the videos are black and white night shots, it is difficult to tell if there is but one fox or two, meaning a mated pair.

Section I

Gray Fox Parenting – Cute and Dark – Part III

Early that morning I met with a reporter who was doing a story about my work with the gray foxes and the corridors woven throughout the edge of the San Francisco Bay. We were there in what I call Fox Hollow Hill, the location where Mama Bold and Gray had decided to hang out for several weeks. Their five young pups were around and about, a couple of them chasing each other in turn, others settling under the edge of dead branches watching as we neared them.

Off along the back road, a fox came trotting toward us. At first, it was difficult to make out which fox it was but as it drew near, I recognized Gray and he carried a dead rodent in his jaws. I nudged the reporter and said, “Look, that’s Gray and he’s bringing in some food for them.” Gray dropped off the squirrel near his pups and all five of them dashed over to it and with screaming cries and sharp yips, and a flurry of pup fur, all of the pups at once tore at each other and at the squirrel. Mama and Gray had yet to teach their litter about the hierarchy, or maybe even the two parents were letting the pups battle it out so as to eventually learn how to feed in an orderly manner.


Generally, when the pups were still but “balls” of gray to black fur the master hunter Gray would forage out across the marsh, or back under the canopy of bushes and trees to hunt and catch food, while Mama Bold usually lay off somewhere somewhat distant from her pups. At this stage, in their growth, she only came to them when it was time to nurse. Often Gray came to her lying beneath the tall Italian Buckthorn bush, gave her a nudge then looking back toward the natal den. Mama stood, stretched, nuzzled Gray under his chin and seemingly, reluctantly she walked back into the brush under the Alkaline Salt Bush. Later, once the pups were ready to learn how to hunt, Mama and Gray hunted together, often accompanied by the alpha pup of the litter.

Meanwhile over along the creek, Midget, the only pup that Cute and Dark had that year in 2014 was a fighter. In contrast to Mama Bold and Gray, Cute and Dark seemingly did nothing together. There were times when Dark would vanish from the area down along the creek leaving Cute alone. I often found her lying under the low hanging willows at overflow channel marker number 20.


I witnessed times when Dark was in the region when Cute wanted his attention. She’d become highly submissive: ear laid back on her head, belly low to the ground and she’d slink along toward him, begging for attention. On rare occasions, he accommodated her but more often than not he’d walk off, back under the brush to be alone. At times like that, I suspect that Cute walked off with hurt feelings, the feeling that her mate had just rejected her.

On several occasions, back in the big clearing deep in the brush and woods, Cute pinned down her pup Midget and give him an ear cleaning. When he wouldn’t hold still, she’d plant her paw on his head and shove him down so that he’d be still enough to get his ears cleaned. The moment that Cute finished, Midget ran for the safety of the blackberry bushes on the perimeter of the clearing. If several of the foxes were there lying in the clearing, sometimes Dark showed up, but he’d remain off and back toward the brush whereas the others, including his mate, gathered


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Gray Fox Report for September 2016

Gray Fox Report for September 2016
Respectfully Submitted by
William C. Leikam, Co-Founder of the Urban Wildlife Research Project (UWRP)

One Eye the Pup at the Overflow Channel

c-baylands-pm-2016-09-15-008-cute-darks-gray-fox-pup-one-eye-eye-cropped-close-goodThursday, September 1, I noticed that one of the gray fox pups that I have come to call One Eye, over on the creek had a swollen left eye. Upon close examination, it looked infected as a dark drainage oozed from the corner of its eye. Over the month, I have watched it develop: The swelling increased and on the upper part of the eyebrow, there appeared to be a small cut as if it had been raked by a claw or something sharp, possibly a dry blackberry thorn, or a jagged, broken branch. The ooze decreased then returned. This cycle has occurred upward of four times over the course of the month.

Gray the Alpha Male at the Embarcadero

Once again, almost non-stop from more than a year ago, Gray has a new infection that bothers him so much that he frequently wipes his eye with his dew claw. Early in the month, he had that ugly puss-like drainage at the corners of both eyes, but as time passed the right eye cleared up, leaving oc-baylands-2016-09-24-124-gray-fox-adult-alpha-male-gray-with-infected-right-eye-close-up-infection-goodnly his left eye infected. From my log of September 17, 2016, “Gray’s left eye is infected. It’s running and nearly closed.” His eye got worse and several days later Gray was essentially blind. By the end of the month, on September 28, 2016 Gray’s eye seems to be almost clear of any drainage, but given past performance it’s apt to come again. I am beginning to suspect that at least with Gray that this infectious bacterium is systemic; it lives within his system.

One of Gray’s pups also has such drainage in its left eye.

Dark the Alpha Male at the Overflow Channel

Alpha male Dark is almost a repeat of Gray’s condition. The only exception is that Gray has had these eye infections far longer than Dark. I wondered why it was that these foxes tend toward getting these infections. Is it something in the environment? Did the infected foxes get into a fight? Did each one collide with something and then become infected?

As a conclusion, I need to point out that not all of the foxes that I monitor are so infected. Most of them have clear eyes. Some of the others have other problems as I have reported in the past such as at certain times of the year being infested with vermin of at least five kinds, and/or leg and ear injuries due to fights generally occurring over food.

General Health of the Gray Foxes

Gray fox scat is the most direct way to tell how healthy the population is or how compromised it may be. Other than my previous report of the two pups in the August Gray Fox Report, the scat appears to reflect a relatively healthy gray fox population at the baylands. Endemic to these mammals are worms in their digestive tracts. Both Dark Eyes and Cute show the presence of worms in their scat.

Total Numbers Of Gray Foxes in the Palo Alto Baylands Preserve

This month I need to modify the number of gray foxes in the area. The foxes that once lived at the golf course have moved. According to one of the workers reshaping the area, they have retreated on over across San Francisquito Creek near the Friendship Bridge. That means that five foxes are no longer being tracked leaving a total of 17 foxes living between Embarcadero Road and Adobe Creek. I might add here that there are gray foxes living in the thickets along the overflow channel that are wild and do not show themselves.

Update for the Urban Wildlife Research Project – Greg Kerekes & Bill Leikam

As an update on events occurring with the Urban Wildlife Research Project:

As of last Friday, September 30, 2016, a new video about the fox work at the baylands was produced and posted online by the Peninsula Open Spaces Trust (POST).

If you haven’t had a chance to read at least some of the articles that have been written about our study of gray fox behavior and our corridor work, click on these links as they will take you to the source: Bill Leikam – The Fox Guy and Greg Kerekes and UWRP.

Beth Pratt-Bergstrom’s new wildlife book When Mountain Lions Are Neighbors covering not only Mt. Lions but as well other wildlife, has been officially released on the book shelves as of August 1, 2016. Within, the book there is a chapter that covers the Urban Wildlife Research Project’s documentation of the gray fox. Please purchase a copy of this valuable book. All proceeds will be used to fund these important wildlife projects in California. To purchase through Amazon.

To find out more about us, search Greg Kerekes, Bill Leikam – The Fox Guy, Urban Wildlife Research Project, UWRP, gray foxes, corridors, and more.

We changed the URL for our website to
Check out our UWRP Facebook Page.

Within the permit that allows the Urban Wildlife Research Project to conduct its study of the behavior of the gray fox, the objectives covered are:

Monitoring of urban gray fox denning sites in Palo Alto Baylands.
This is being accomplished during the period when the gray foxes use a den site. It is one of the prime locations for gathering most of the behavioral data on the litter and on adults alike.

Assessment of status and population trends of Bayland’s urban gray foxes.
See above – As of June 2015, it appears as though the number of gray foxes at the baylands has declined considerably. This brings up the question: As with coyotes that can regulate the number of pups born in a region, might also gray foxes do the same?

Identification of habitat features that promote the presence of urban gray foxes.
As stated in a previous gray fox report, there is a need to undertake some work to increase the habitat features required by the gray foxes and other wildlife in an area where a road was built that borders the saltwater channel. I asked construction supervisor Frank Muzzi about this and he felt that the old growth Coyote Bush would grow back within the coming year and therefore accomplish the same goal. After considering this and talking with people who know how to restore habitats, we need to assess what kinds of plants would grow best along the edge of the saltwater channel and alongside the marsh. The Alkaline Saltbush is one but there are probably others as well. We need to grow a permanent habitat that contains the corridors and plant it as soon as possible. We’ll keep an eye on this as this is a critical link between the southern region of the baylands and the northern region.

Assessment of reproductive success and identification of factors that promote successful reproduction.
Last month I wrote that gray fox reproduction at the baylands appears to be holding steady with an average of 3.3 pups developing to maturity during the 2013 and 2014 seasons. As noted above, the 2015 season has fewer pups than in years past.
Solution? Open up the pinch-point along Matadero Creek by developing thickets that link one area to another.

Identification and assessment of possible dispersal travel routes.
Presently there can only be guesses as to dispersal travel routes. We intend to make this important question much more concrete when we attain our collaring/take/capture permit from the Department of Fish & Wildlife.

Until next month, I hope that your endeavors are productive and rewarding. Take care.

Bill Leikam – The Fox Guy
Urban Wildlife Research Project

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Cities & Sea Level Rise

Along with the city of Palo Alto’s climate action plan, they will have to consider establishing wildlife corridors within the city. As the bay inundates large portions of the bay-lands, it will push all of the wildlife that is presently around the edge of the bay into the cities. This wildlife will need places to live, corridors to move from one place to another, hunting grounds, territories, etc. What will the Palo Alto do to accommodate them? How will Palo Alto educate the people whose backyards have become a part of the wildlife habitat? We are going to have to learn to live side-by-side and do so peacefully. How will Palo Alto address these issues with the people who will be affected before they find that their property contains foxes, raccoons, opossums, etc?

Incest at the Baylands

Gray Fox Report for February 2016

Respectfully Submitted by William C. Leikam, Founder of the Urban Wildlife Research Project (UWRP)

Date Submitted: Wednesday, March 05, 2016


February is the time when the females are in estrus (heat is the common term for that condition) because the foxes give birth to their young sometimes in late March but most often in April. Sex for the gray fox comeC - Baylands PM -12-13-2015-038 - Gray fox female Pale hangs out with young male Blackies only once per year and so it is a very important time and the foxes know it. Both males and females make it abundantly clear: Males that they are looking for a female in heat and females announce to all males in the area when they are in estrus or within hours of so being. It is during February that some males and females are polyandrous, meaning that in many cases they have multiple sex partners. They do not always discriminate between sexual partners and it is possible that the female’s mate will not necessarily be the genetic lineage of the pair. (See Multiple paternity and kinship in the gray fox (Urocyon cinereoargenteus)  Julie L. Weston Glenn, David J. Civitello , Stacey L. Lance)

Continue reading Incest at the Baylands

Rodenticide: Impacts and Alternatives

Cat with mouseThe food chain is sacred, continual, and encompassing. Rodenticides are a major threat to food chains around the world.

Animals that are adapting to civilization or venturing into human inhabited  areas seeking food, water, and shelter, are at risk of consuming a poisoned rodent and dying as a result of Secondary Rodenticide Poisoning. This includes predatory wildlife including birds, mammals, reptiles, and amphibians and even your pets. Many pets and humans have had fatal encounters with the poison bait and it has proven in many cases, unsafe to use indoors.

Bold(female) with Rabbit Bill Leikam ©2013
Bill Leikam ©2013

In my neck of the woods, sunny California, there are over 23 species of carnivorous mammals and over 40 species of predatory birds. These creatures feast on the 100+ different species of small rodent like mammals, including: mice, voles, gophers, and squirrels; all potential targets for rodenticide.


IMG_5859Last week in California news, two disturbing stories surfaced relating to rodenticide poisoning.  First, a Red-tailed Hawk in a Safeway parking lot in S.F. was seen picking up and eating a deceased mouse it found next to a baiting station. Often, the creatures that ingest the poison can be found exposed, in search of water or dead outside of rodenticide bait stations, easy pickings for hungry predators.


RodentcideAnother tragic example of Secondary Rodenticide poisoning, came from Los Angeles: 3 Dead Mountain Lions in the Santa Monica Mountains in  L.A. , one of the three was confirmed dead from rodent poison. Unfortunately, earlier this year UWRP deduced that pups of a Gray Fox family in Silicon Valley may have suffered the same fate. And, according to The Felidae Conservation Fund, there are similar issues with Bobcats in the Santa Cruz Mountains.


These instances cannot go unrecognized.

Change needs to happen if we are to attempt to co-exist with wildlife. “Prevention is the key”, Rebecca Dmytryk of Humane Wildlife Control explains,”instead of rodenticide, focus on what attracts the rodents to your property.”

  1. Prevent access to shelter, by sealing entrances and cavities outside and inside with wire mesh, wood paneling, steel wool, and expanding foam. Clean up woodpiles and yard debris.
  2. Eliminate the rodent’s food and water sources. Do not feed pets outside and leave food unattended. Clean up spilled bird seed at the feeder. Remove English Ivy which provides food, water, and shelter year round for rats and mice.
  3. As far as traps go T-Rex easy set spring loaded trap is recommended, only use snap kill traps indoors and do not use inhumane sticky traps. Wildlife such as bats, birds, lizards, skunks, raccoons and others may encounter a trap outside.
  4. Install a Barn owl box! However, before installing an owl box, make sure your neighbors are not using Rodenticide, so you don’t attract an owl to an unsafe area.

©Greg Kerekes 5 WBO ChicksUWRP        In conclusion,  human ingenuity has allowed us to be able to out smart the little rodents that sometimes plague our lives, without damaging the food chain.

Please consider compassionate alternatives and aid the effort to educate citizens on the dangers and impacts of Rodenticides to our environment.

Take Action!

Feel empowered to take this information to your employer if you see rodent bait stations outside your place of work.

A few years ago, I noticed bait stations placed in a private soccer field belonging to a tech company, with a campus along the Guadalupe River in Silicon Valley.  UWRP and Santa Clara Valley Audubon, approached Philips electronics regarding the existence of Burrowing Owls and Gray Foxes in the vicinity of rodent bait stations on their property. Corresponding emails resulted in Philips changing to non-poisonous rodent control methods, as well as  the removal of their poison bait stations from around their Silicon Valley LED campus.

Change is quick once people realize the impact Rodenticides are having on the environment. The key is education. 

Written and edited by:

Greg and Alexandria Kerekez

Here are some great educational resources about the impacts of rodenticide and humane alternatives: and

Watch the Gray Foxes of Silicon Valley to hear from expert Rebecca Dmytryk on Co-existing with wildlife.

For short, groovy, educational videos by Dance Naturalist John Griffith regarding this topic, watch “Rat Poisons Suck!” 

and “Sticky Trap Catches Lizard”

Don’t forget to Share this article and the National Parks Awareness Infographic to broaden the awareness of the negative impacts of Rodenticides.

Gray Fox Report for July 2015

Gray Fox Report for July 2015

Respectfully Submitted by William C. Leikam
Founder of the Urban Wildlife Research Project (UWRP)
Date Submitted: August 5, 2015


In June’s email I opened, “With the loss of the litter around the water treatment plant, with Little One in seclusion and none of the other females in the region having a litter [that I know of], the only female to have a single pup seems to be Dark Eyes.” During the month of July, I had to correct that. It wasn’t Dark Eyes who had the single pup. Instead it was Cute and her mate the alpha male Dark who have the single pup. Dark Eyes may have a litter but if so, she is keeping it hidden and even at night for I have not seen any of her pups on my cameras. As we enter August, I grow more and more skeptical that she has a litter at all.

Continue reading Gray Fox Report for July 2015

Study of urban wildlife