Territorial Division and Mange

10 Feb 2026 8 Comments

by yipps:janetkessler in divided territories, mange

A scruffy, thin coyote standing in a natural environment, surrounded by green plants, with a focused expression.

I’ve written several postings with information about mange. One on how the malady has just recently exploded here in San Francisco, and another on how weakened immune systems allowing the mange mite to proliferate on a coyote host have been linked to the use of rat poisons. But there are other stressors which raise cortisol which in turn weaken immune systems, allowing the mite to take over. An interesting correlation (maybe related) is that San Francisco’s coyote population might have reached an over-saturation point, as indicated by territories being divided up and shared at the same time that mange has spread wildly through the city. It’s this correlation that I’m attempting to point out.

2024 marked the breakup of one of San Francisco’s long-term stable coyote territories: This territory had been stable since 2007. The shift began when Scowl, the alpha male, left his older mother-turned-mate, Chert, after two years of fathering and raising a family of pups with her. Whether age played a role, I don’t know — but he soon turned up with a younger female, Bonus, on her much smaller territory, where they had pups that year.

Left behind was Chert, aging, along with three yearlings. Several new males passed through, but appear to have been rejected. the one who remained for several weeks had mange. Within months Chert and her offspring had mange. In addition, this is when a mangy “squatter” pair of coyotes moved into a portion of her territory, maintaining their separation from Chert’s family. Their pups did not survive, and the pair left by early summer — but the area had effectively become shared space.

2024 was also the year mange appeared to take hold across the city.

After Chert died towards the end of the year, 2024, two of her offspring remained and claimed the southern portion of what had once been her and Scowl’s shared domain. This kind of territorial inheritance — offspring retaining natal land — has characterized this lineage since 2007. In fact, it characterises a number of San Francisco’s territories, but not all of them.

Meanwhile, Scowl eventually led Bonus back to his former territory, reclaiming the northern section. By 2025, what had once been a single large territory was permanently divided in two. The families are closely related — both are offspring of Chert’s from different years — but they never interact, maintaining a firm boundary.

Another divided territory: Scout’s story

Scout originally acquired her territory after it was vacated — a rare and lucky find. Yet in 2022 she denned about a mile away, possibly because of her mate Scooter’s family ties there. Even so, during this time, she continued returning to her original territory, where earlier offspring remained, almost as if holding it for her.

In 2023 she returned to her original old territory full-time with a new mate, Skipper, and they stayed for two seasons. But in 2025, one of Scout’s daughters resisted dispersal. So it was Scout and Skipper then who abruptly left, returning to the territory she had denned in a mile away, where they squeezed the other claiming family into a less desirable portion of the park.

That displaced family developed severe mange; Scout and Skipper had milder cases but recovered. Once again, the territory appears permanently divided, with mange disproportionately affecting the weaker group.

Shared space and shifting use

In 2025, two families shared the Sunset area, using the same passageways at different times of day or evening. Both alpha pairs had serious mange.

A similar pattern is now emerging in a denning area of West Portal. After Mouse — the territorial female — was killed by a car in 2022, the area became something of a no-man’s-land. Coyotes came and went: loners, then pairs. But by 2024-25, three mangy pairs were using this small area regularly.

An open question

Across these examples, territorial divisions and shared-use areas appear to coincide with mange outbreaks beginning in 2024. Population pressure appears to be driving these divisions. Does crowding and social stress increase vulnerability to disease and accelerate its spread? I don’t know whether these patterns are causal or coincidental.

I’ve simply observed the overlap. Determining whether one feeds the other is a question best left to someone with an infectious-disease background — but the pattern itself is becoming hard to ignore.

More on Mange in San Francisco

13 Jan 2025 1 Comment

by yipps:janetkessler in mange Tags: , ,

Video shows the progression of mange from none in June, and then the case progressing from September through December of 2024.

Just a few days ago, on January 9th, the Chronicle reported that: “Mange outbreak in S.F. coyotes poses risk to pet dogs, officials warn”. Please be informed that mange is transferred through contact, but it has to be through cozying-up or sharing bedding, which our dogs don’t do with coyotes because coyotes and dogs don’t intermingle. A chase, or a nip does not spread mange. I’m surprised that, yet again, both the Chronicle and our City departments have put out sensationalist and fear-mongering information without thoroughly vetting this. This is just more misinformation which will turn folks unnecessarily and wrongly against coyotes.

I’ve spoken to a number of veterinarians and rehabbers who have repeated the same thing to me over and over again. In other words, mange in coyotes poses little risk to dogs.

In addition IF perchance your dog gets mange, it’s easily treated because our pets have ready access to medication and care. This is not true of coyotes. However, I read in Wikipedia that “stressors influence severity and duration of the infection, and that most individuals recover from mange, which helps protect them from future mange infestations. For example, a lactating coyote may look terribly infected with mange, but will likely recover after the pups are weaned and the additional stressors on this coyote are decreased.” 

From my own observations: The early signs of mange might be hard to detect in individual coyotes right off. They include crusty eyes, hairless tails and ears, and a sort of splotchy appearance. This progresses fairly rapidly to more and more hairlessness and crusty patches on the skin unless it is arrested by a prescription drug called Bravecto — this is something that can be given them in the wild without intruding or interfering in their lives, without trapping them or bringing them in. If the case is too far along, even this won’t help, and the animal might need a stronger drug called Ivermectin which MUST be given in two doses and with the right timing to work and normally is administered in a rehab center. Few people know coyotes well enough to notice mange in its early stages, and even now, with extremely furless animals, most people are simply reporting that they see very small coyotes.

I’ve watched a number of cases improve over a six to eight week period of time: the biggest improvement is the healing of crusty eyes and a fuller coat. It seems it takes longer for tail and ear fur to grow back.

You can see an improvement and healing of the crusty skin around the eyes.

We have had few cases at all of mange here in San Francisco since 2002 when coyotes suddenly re-appeared in the city after many years of absence due to our having killed them off. Last year, 2024 there was a sudden surge in the condition. From what I’ve seen, the infected animals seem to have came in from south of the city where we saw the first few cases. One of these individuals made it to a park in the heart of the city where he attempted pairing up with an old female whose mate had left her — possibly because she was getting old — I posted this in mid-January. That guy hung around for several weeks and eventually was chased out, but he was there with the family long enough to spread the mite. In mid-January and mid-February I posted images of this mangy fellow on my Instagram account. Long after he left, come May, the female who he had hoped to pair up with had contracted the mite so severely that I could barely recognize her: see the lower photo on the left below and then pair it up to her healthy look months beforehand. It then spread to four more members of that family. I continued to post about mange through the end of last year — my last such posting was in October.

I noticed that mange almost always spreads to family members: it tends to run in families because these are individuals who indeed do cozy up and share their bedding areas. I know several families where every family member has it. I also have seen individuals spoke off from their families and live alone: I don’t know if these individuals have been excluded from their families because of the mange, or if they themselves, in their very uncomfortable situation, went off on their own to better cope with the condition. There’s also the possibility that their leaving had nothing to do with mange. Those that are off on their own are yearlings whose internal call to disperse may have pulled them away from those families. But these individuals are hanging around the periphery of their birth territories for longer than I have usually seen.

So I know of four families that have passed the mite between themselves. But there are families that, so far, knock-on-wood, seem to be totally unaffected by it. In the past we’ve rarely if ever seen mange here in Francisco. Of the individuals I saw, I did not know who they were (they were not members of the families I had mapped) and they were soon gone, leading me to believe that they were dispersing individuals that made it into the city from the south, and then left again once they could not find territories here. It never spread in the city until last year, 2024.

The above healthy coyote photos are the same individuals as the ones right below them with mange.

See my previous posting in October: https://coyoteyipps.com/2024/10/03/mange-cases-are-growing-in-san-francisco/

Article describing mange: https://dfwurbanwildlife.com/2019/11/07/chris-jacksons-dfw-urban-wildlife/why-its-challenging-to-treat-coyotes-with-mange/

Instagram posting on mange: [https://www.instagram.com/p/DD5EFQSRhhB/?img_index=1]

Online Treatment of Mange (check your local area for protocol and guidelines): https://owl-online.org/wp-content/uploads/2020/10/Treating-Sarcoptic-Mange-in-Coyotes-and-Foxes.pdf

© All information and photos in my postings come from my own original and first-hand documentation work which I am happy to share, with permission and with properly displayed credit: ©janetkessler/coyoteyipps.com.

Mange Cases Are Growing in San Francisco

03 Oct 2024 7 Comments

by yipps:janetkessler in mange, Uncategorized, video Tags: , , , ,

I’m visiting mange again. This video shows a young mother coyote who developed the condition over the summer. The first part of the video was taken in mid-September showing her ragged tail and pocked face. The last part of the video — for comparison — was taken in mid-June when she was still not afflicted.

I’m seeing more cases of the horrible disease here in San Francisco, whereas two years ago I never ever saw it at all here. Mange is caused by a small mite which burrows deep into the skin of canids, where it lays its eggs and multiplies, causing intense itching and unsightly scabbing and hair loss, mostly around the face, ears, legs and tail. It’s a horrible and painful condition. 

There are two types of mange apparently: sarcoptic and demodectic, which are caused by different mites. Sarcoptic mange is very contagious and is caused by a roundish, eight-legged mite. Demodectic mange is not contagious and is caused by a cigar-shaped mite which actually all canids carry: their healthy immune systems keep the mite in check naturally. However, when immune systems are weakened, this mite can take over and results in mange. Rat poison is known to weaken immune systems.

Some of the afflicted animals are able to mount an immune response to mange, but many succumb to eventual dehydration and starvation, and secondary infection.

My information about mange (above) comes from the American Kennel Club: https://www.akc.org/expert-advice/health/mange-what-you-need-to-know/

A systematic review of the effectiveness of some wildlife treatments can be found here: https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-019-3340-z

CAFW, possibly through a licensed rehabber, can administer a medication known as Bravecto (Fluralaner) in the wild without removing a coyote from its territory or family situation: this medication improves their condition noticeably. A stronger medication is Ivermectin, but this medication requires monitoring, which is difficult in wild animals. If you have questions about a coyote with mange, please contact the folks at @yggdrasilwildlife or @claremont_wildlife_habitat.

RAT POISON in Smaller Doses — When It Doesn’t Kill Right Off

20 Mar 2017 3 Comments

by yipps:janetkessler in mange, poisons, rat poison

Rat poison kills by use of the ingredient warfarin, or a second generation thereof, which thins the blood. In small doses, humans take a similar drug known as cumaden to prevent strokes. In high doses, these kill by causing the organism to bleed internally — massively. It’s a horrible, tortuous death. It should not be allowed. Rats can be eliminated in a more humane manner if need be.

Very small doses of rat poison may not immediately kill the owl, hawk, or coyote that consumes the poisoned rat, but the effects are just as insidious over a longer period of time. The poison accumulates and compromises the ability to live in various ways, most notably by slowing them down. They are not as alert or as fast or as acute as they once were, so living becomes more difficult and even dangerous for them.

One of the effects of rat poisons on coyotes is that it compromises their immune systems, leaving them particularly vulnerable to parasites, including mites of all types. The worst, of course, is mange. Rat poison doesn’t cause mange, of course, but it can be a highly contributive factor because it weakens the immune system which fights off these mites. If you see a coyote whose fur is riddled with mites, or who has mange, it may very well be rat poison which allowed the mite infestation to take hold.

Please don’t use rat poison. Also, please try and help any animal that has an ailment — they can be helped by calling your wildlife rehabilitation agency.

Rats can be eliminated in a humane way. The best way is by exclusion and removing the attractants: plug up the holes in your home and remove/contain food sources. Within two weeks, they’ll leave. Alternatively, there are high-frequency devices which drive the animals away (but probably also the birds). Lastly, you can call a pest-removal service that uses humane traps. Please note that most private pest-management companies will either drown the rat or suffocate it to death with industrial strength carbon dioxide – both methods are extremely painful. The animal needs to be killed humanely.

To find a trapper in your area, please Google “humane trapper”. For rodent control alternatives, please visit www.wildcarebayarea.org/rodenticide or www.wildlife.ca.gov/Living-with-Wildlife/Rodenticides.

Coyote Afflicted with Mange in Danville, CA is Hit By A Car

12 Sep 2016 Leave a comment

by yipps:janetkessler in coexisting with coyotes, lone vs. pack activity, mange

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2016-09-06-danville-coyote-mange

Hey everyone, the rules of “don’t feed” are to discourage healthy coyotes from hanging around, but when a coyote, or any animal for that matter, obviously and badly needs help, we need to help it. The advice given to this neighborhood — to not leave out food or water — was thoughtless advice imposed from “rules” that have become too generalized.

Coyotes who are affected by mange, or anything that alters their appearance, are shunned by other coyotes and ousted from their social groups and their territories. Besides causing a very obvious change in the coyote’s appearance, mange also is extremely contagious. The mite causing the skin disease burrows deeply, causing excruciating itching. The coyote scratches so hard that bald spots result on his skin. The skin, then, cannot carry out its protective function. Slowly, all bodily functions become diminished.

The shunning of such an animal by other coyotes may serve to isolate the animal so that these other coyotes do not get infected by the mite. Shunned animals have to make it on their own now, in unfamiliar areas where they may not know the best food sources. So they become more visible not only because they look odd and have lost their camouflage, but also because they are now moving around in new, unfamiliar areas where survival is now that much more difficult. So mange causes both social and bodily issues for coyotes.

People could have helped this coyote both with food and with medications until the animal could be caught and helped more intensively. Instead they were instructed to stick to “rules” which did not fit “the case”. Let’s be humane towards our wild animals — here we could have helped abate the misery of an already suffering animal.

http://kron4.com/2016/09/05/sick-danville-coyote-reportedly-hit-killed-by-car/

Fur, Bugs

24 Jun 2013 2 Comments

by yipps:janetkessler in coyote health problems, coyote's coat, mange, scratching, shedding Tags: , , , ,

I’m seeing big fat ticks these days, and I’ve suspected that fleas also are rampant because of all the scratching and the resulting loss of fur. But, it turns out that all the scratching may have less to do with bugs than I thought!

constant scratching causes hair loss

constant scratching causes hair loss

The veterinarian suspects the loss of fur may be due not only to the pesky bugs which cause a lot of itching and therefore scratching, but also may be due to the coyote’s helping with the seasonal shed — it appears that coyotes have been using their hind paws — scratching often — in order to get all that itchy dead fur out.

it's not mange; note pattern of hair loss where hind leg can reach

it’s not mange; note pattern of hair loss where hind leg can reach

Coyotes are approaching the time of year when their coats are at their thinnest. But the fur is exceptionally sparse just where those hind legs can reach on the back at the shoulder blades and behind the ears. That is where almost all the scratching is occurring! The rest of the fur is coming off more naturally and at its own pace.

hair loss behind ears

hair loss behind ears

The scratched spots looks mangy, but I’m told that mange is systemic and would not appear just where they can reach with their hind legs. So it’s other things: ticks, fleas and seasonal shed, but no mange. That was a relief to find out!