Coyote Dispersal Season Starts This Month. Of 247 Denver-Area Pet Attacks With Detail Recorded, 76% Were on Dogs — Not Cats.

September 29 is Urban National Wildlife Refuge Day — a nod to the 101 refuges the U.S. Fish and Wildlife Service manages within 25 miles of a city of 250,000 or more.[1] It's a good excuse to talk about the wildlife that didn't wait for a refuge to be established and simply moved in.

It's also the right month for it. Coyote pups born in April are now most of the way to adult size and starting to leave. Researchers studying Chicago's coyotes define the dispersal season as September through December;[2] Illinois' DuPage County forest preserves put it at October through February;[3] Massachusetts wildlife simply says the pups "disperse on their own in late autumn."[4] Whichever line you draw, the practical effect is the same — young, inexperienced coyotes are moving through unfamiliar ground right now, and more people are seeing them.

Around Chicago, dispersing young coyotes travelled a median of 8.1 km and a mean of 18.1 km, with a range from 1.7 to 60 km.[5] In less-developed landscapes the same animals go 51 to 310 km. Cities are a patchwork, and a young coyote can spend weeks crossing one.

What the incident data actually looks like

The best dataset on pets comes out of Denver. Researchers reviewed 4,006 coyote reports from the Denver metro area between January 2003 and June 2010. Most — 87.3% — were simply sightings. Of the 510 reports classed as conflicts, 471 (92%) were attacks on a pet.[6]

For 247 of those attacks there was enough detail to identify the animal: 188 (76.1%) were attacks on dogs and 54 (21.9%) were attacks on cats.[6] Those percentages are of the detailed subset, not of all 471 — worth keeping straight if you see the figure repeated elsewhere.

The Cook County research out of Chicago breaks the dog attacks down further. Across 70 attacks on dogs between 1990 and 2004, involving around 30 breeds, 20 were small breeds, 3 medium and 6 large. Yorkshire terriers and shih tzus topped the list with six each, followed by Jack Russell terriers and Labrador retrievers with five.[7] Attacks on small dogs were more often fatal; larger dogs were more often attacked by two or more coyotes at once.

Cats are underrepresented in these counts for an unglamorous reason. The same Cook County work logged only 10 cat attacks, and nearly half were unconfirmed — a cat that doesn't come home is a missing cat, not a recorded attack.[7]

The dawn-and-dusk thing isn't supported

This one gets repeated constantly, including by people who should know better. The Cook County researchers looked and wrote it plainly: they "did not find a meaningful difference in the number of attacks occurring during daytime versus nighttime hours."[7] A separate analysis of 142 coyote attack incidents on humans between 1960 and 2006 found the same even split — of the 80 incidents with a time recorded, 50% were daytime and 50% were nighttime.[8]

What the Chicago data did find is a season: dogs were more commonly attacked in winter than in spring or summer.[7] The Denver reports peaked during the breeding season, January through April, when 47.5% of all reports came in.[6]

So the useful mental model is closer to "certain months" than "certain hours."

What coyotes are actually eating

This depends enormously on the city, which is why the numbers people cite seem to contradict each other.

In metropolitan Chicago, researchers analyzed 1,429 coyote scats collected between 2000 and 2002. Small rodents were the single biggest item at 41.8%, followed by fruit at 22.7%, white-tailed deer at 22.0%, cottontail rabbit at 17.7% and birds at 13.1%. Domestic cat turned up in 1.3%. Human-associated food came in at 1.9% overall, though it hit 10.7% at the most urbanized study site.[9]

Tucson looks different. A study there used direct observation rather than scat analysis, and across 45 observations of coyotes consuming prey or fruit, cats accounted for 42% of what was observed — and cats were consumed in 18 of 19 observed kills.[10] Different city, different desert-edge landscape, very different answer. Observation and scat analysis also measure slightly different things.

The honest summary: in most studied cities, cats are a small fraction of what coyotes eat, and in some places they're a large one. A national average is not much use to any particular household.

Worth adding that Chicago researchers radiocollared 39 free-roaming cats and found an annual survival rate of 0.70, with cats clustering near human structures and largely avoiding the natural areas coyotes used. The two species were overlapping far less than the shared map suggested.[11]

What actually reduces risk

Fencing. University of California guidance calls for a minimum height of 5½ feet, mesh openings no wider than 6 inches, and a buried wire apron 4 to 6 inches deep extending at least 15 inches outward — coyotes dig. The top needs either a wire-mesh overhang of at least 18 inches slanted outward, or a roller-type device.[12] The overhang is the part people skip, and it's the part that matters for an animal that can clear a plain fence.

Hazing. In a Denver-area study, 207 trained citizen scientists documented 96 hazing events. The most common outcome was the coyote leaving the area — but hazing was less effective when a domestic dog was present.[13] That's a meaningful caveat given that most people hazing a coyote are out walking one. A 2025 Edmonton study using 120 volunteers across 71 neighbourhoods logged 175 sightings over more than 1,300 hours, of which only 23 coyotes even met the criteria for a hazing attempt — most were seen briefly and at a distance.[14]

Keeping cats in, small dogs supervised, and dogs leashed. UC guidance is direct about cats and small dogs staying indoors or in enclosed kennels, and large dogs coming in after dark.[12] The leash point is doing more work than it looks like: a dog off-leash at distance is a dog you can't intervene for.

What doesn't have evidence behind it: coyote rollers and spiked anti-coyote vests are widely sold and may well work, but there appears to be no peer-reviewed study measuring either. Treat the marketing claims as claims. That isn't a reason to skip them — it's a reason not to rely on them as the only layer.

A note on habituation

A 2026 paper in Animal Behaviour examined an unusual cluster: 45 coyote attacks on humans in Vancouver's Stanley Park between December 2020 and August 2021.[15] Aggression was higher during pandemic restrictions that pushed people outdoors, on high-traffic trails, at low-activity times of day, and nearer coyote dens. Victims were more often running and alone. Notably, the presence of a domestic dog had no measurable effect either way — and neither did the victim's age or gender.

The authors' recommendations are unfussy: go in groups, go at busy hours, stay away from dens. Feeding — deliberate or accidental — is the mechanism underneath most of this, and the Stanley Park cluster ended only after the park was closed and the habituated animals removed.

The practical list

• Walk on a leash, particularly at this time of year and particularly with a dog under about 25 pounds. A retractable leash at full extension is functionally off-leash.
• Bring cats in. If that's a hard sell in your household, a catio or a supervised harness routine gets most of the benefit.
• Take the food away — fallen fruit, birdseed that feeds rodents, unsecured bins, pet bowls left outside. Every study above points back at food.
• Don't run from one. Make yourself large and loud, and move toward it rather than away. Carry something that makes noise if you walk at odd hours.
• Fix the fence properly if you're going to fix it at all: height, buried apron, outward overhang.
• Make sure your pet's ID would work if the worst happens and they bolt rather than get caught. A coyote encounter that ends with a dog running two miles in a panic is a common enough outcome, and a current tag and registration is what turns that into a phone call.

Coyotes have been in North American cities long enough that removing them isn't on the table, and the research fairly consistently finds that the animals aren't hunting pets so much as taking what the landscape offers. Most of the risk sits in the ordinary decisions — the leash, the fence, the bin lid — rather than in the coyote.

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Sources

1. U.S. Fish and Wildlife Service. "Urban Wildlife Conservation Program." https://www.fws.gov/program/urban-wildlife-conservation
2. White LA, Gehrt SD. "Coyote Attacks on Humans in the United States and Canada." Human Dimensions of Wildlife, 2009. https://urbancoyoteresearch.com/sites/default/files/resources/WhiteandGehrt_CoyoteAttacks.pdf
3. Forest Preserve District of DuPage County. "Coyote Dispersal Season." News release, October 24, 2024. https://www.dupageforest.org/what-we-do/news/news-releases/coyote-dispersal-season
4. Massachusetts Division of Fisheries and Wildlife. "Learn about coyotes." https://www.mass.gov/info-details/learn-about-coyotes
5. Zepeda E, Payne E, Wurth A, Sih A, Gehrt S. "Early life experience influences dispersal in coyotes (Canis latrans)." Behavioral Ecology, 2021;32(4):728–737. https://academic.oup.com/beheco/article/32/4/728/6243285
6. Poessel SA, Breck SW, Teel TL, Shwiff S, Crooks KR, Angeloni L. "Patterns of human–coyote conflicts in the Denver Metropolitan Area." Journal of Wildlife Management, 2013. https://wildlife.onlinelibrary.wiley.com/doi/10.1002/jwmg.454
7. Urban Coyote Research Project (Cook County Coyote Project), Ohio State University. "Conflicts: A Research Perspective." https://urbancoyoteresearch.com/coyote-info/conflicts-research-perspective
8. White LA, Gehrt SD, 2009, as above.
9. Morey PS, Gese EM, Gehrt S. "Spatial and Temporal Variation in the Diet of Coyotes in the Chicago Metropolitan Area." The American Midland Naturalist, 2007. https://urbancoyoteresearch.com/sites/default/files/resources/coyote%20chicago%20diets.pdf
10. Grubbs SE, Krausman PR. "Observations of Coyote–Cat Interactions." Journal of Wildlife Management, 2009;73(5). https://wildlife.onlinelibrary.wiley.com/doi/abs/10.2193/2008-033
11. Gehrt SD, Wilson EC, Brown JL, Anchor C. "Population Ecology of Free-Roaming Cats and Interference Competition by Coyotes in Urban Parks." PLOS ONE, 2013;8(9):e75718. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0075718
12. Timm RM, Baker RO, Beckerman JR, Coolahan CC. "Coyote." UC IPM Pest Notes Publication 74135, University of California Agriculture and Natural Resources. https://ipm.ucanr.edu/PMG/PESTNOTES/pn74135.html
13. Bonnell MA, Breck SW. "Using resident-based hazing programs to reduce human–coyote conflicts in urban environments." Human–Wildlife Interactions, 2017;11(2). https://digitalcommons.unl.edu/hwi/407/
14. Lajeunesse G, Harshaw HW, St. Clair CC, et al. "Urban coyotes were observed rarely and retreated consistently from assertive approaches by volunteers in neighborhoods." PLOS ONE, April 16, 2025. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0318127
15. Lewis KP, St. Clair CC, Harrower WL, Benson-Amram S. "Habituation, den defence and predatory opportunism appear to have contributed to coyote aggression in an urban park." Animal Behaviour, 2026;238:123617. https://www.sciencedirect.com/science/article/pii/S0003347226001545

If a coyote in your area is behaving unusually — approaching people, showing no avoidance, active around a den near a trail — your state or provincial wildlife agency is the right call.