{"id":10417,"date":"2025-10-20T21:26:40","date_gmt":"2025-10-21T05:26:40","guid":{"rendered":"http:\/\/inedc.com\/26\/?p=10417"},"modified":"2025-10-20T21:26:40","modified_gmt":"2025-10-21T05:26:40","slug":"mountain-lions-in-el-dorado-county-peak-at-dusk-and-after-dark-local-monitoring-shows","status":"publish","type":"post","link":"http:\/\/inedc.com\/26\/news\/mountain-lions-in-el-dorado-county-peak-at-dusk-and-after-dark-local-monitoring-shows\/","title":{"rendered":"Mountain lions in El Dorado County peak at dusk and after dark, local monitoring shows"},"content":{"rendered":"

PLACERVILLE, Calif. \u2014 An independent analysis of 107 mountain-lion sightings in El Dorado County found that most confirmed detections cluster around evening and early-morning hours, with camera traps showing a pronounced nocturnal peak and resident reports spread more evenly across the day, researchers said.<\/p>\n

The analysis \u2014 compiled from social-media posts (Facebook, Nextdoor), submissions to an EDC Carnivore Project reporting form and direct communications with project researchers \u2014 examined only sightings that included a specific date and time and removed ambiguous or misidentified reports. Camera detections (remote home-security and trail cameras) drove the strong nocturnal signal: camera records clustered around 01:00, with secondary early-morning and evening peaks, while firsthand (human) reports were distributed more uniformly over 24 hours. The combined dataset produced a statistically significant clustering overall, with a notable evening peak near 20:00\u201321:00.<\/p>\n

The project separated reports into two types \u2014 FIRSTHAND (observed directly by a person) and CAMERA (recorded by trail or home-security cameras) \u2014 and used circular statistics and camera-trap analysis tools in R to test whether sightings were uniformly distributed across the day or concentrated at particular hours. Researchers used Rayleigh tests to detect clustering, Watson\u2019s two-sample tests to compare the two sighting streams, and a bootstrap overlap analysis (5,000 iterations) to estimate temporal overlap between firsthand and camera records. Those methods are described in the EDC Carnivore Project\u2019s reporting materials. El Dorado County Carnivore Project<\/span><\/span><\/span><\/a><\/span><\/span><\/p>\n

\u201cLarge-cat populations are flexible in their timing,\u201d said Ellie Bolas, lead author of a recent UC Davis study of mountain-lion activity in the Los Angeles region. \u201cThis flexibility we see in mountain lion activity is what allows us to share these natural areas together.\u201d Bolas\u2019 work documents how mountain lions shift activity toward nighttime hours in areas with high human recreation, a trend that mirrors the pattern the El Dorado monitoring recorded.<\/p>\n

Why the difference between camera and human reports? Researchers say camera systems operate continuously and pick up animals when people are not present \u2014 overnight and in the early morning \u2014 whereas human sightings reflect when people are outdoors and awake. Still, the analysis found a meaningful overlap: dusk hours (around 20:00\u201321:00) were common to both detection types, making dusk a key window when residents and mountain lions are most likely to cross paths.<\/p>\n

The researchers also note 18 firsthand sightings during daytime hours (07:00\u201319:00), which could reflect individual animals with atypical behavior, increased tolerance or habituation to human presence, or simply chance encounters. The report recommends follow-up spatial analysis to see whether daytime reports cluster geographically \u2014 which could indicate a localized animal or hotspot \u2014 and cautions that population-level conclusions require larger datasets and continued monitoring.<\/p>\n

State wildlife resources describe mountain lions as primarily nocturnal and crepuscular (active at dusk and dawn), but flexible in timing depending on prey, human activity and habitat. Local sunset and sunrise times shift by season in Placerville, which can move the hours when dusk and dawn occur; normalizing sightings to local dusk\/dawn times would help refine seasonal comparisons, the report says.<\/p>\n

Practical takeaways for residents<\/p>\n