User:Sturgafish/Santa Monica Mountains

Climate
The Santa Monica Mountains have dry summers with frequent coastal fog on the ocean (south) side of the range and rainy, cooler winters. In the summer, the climate is quite dry (except for the coastal fog), which makes the range prone to wildfires, especially during dry "Santa Ana" wind events.

The lower slopes of the range average between 15 and 20 inches (380 and 510 mm) of rain per year, while the higher slopes of the central and western Santa Monica Mountains average 22 to 27 inches (560 to 690 mm) of rain per year. The bulk of the rain falls between November and March. The higher rainfall in the central and western parts of the range results in more widespread woodlands (with oak, sycamore, walnut, bay laurel, alder and other trees) than the eastern part of the range, where trees are usually restricted to the stream courses.

Snow is unusual in the Santa Monica Mountains, as they are not as high as the nearby San Gabriel Mountains, but not unprecedented. On January 17, 2007, an unusually cold storm brought snow in the Santa Monica Mountains. The hills above Malibu picked up three inches (eight centimeters) of snow - the first measurable snow in fifty years. Snow was reported on Boney Peak in the winter of 2005; and in March 2006, snow also fell on the summit of the mountain. Snow also fell on the peak of Boney Peak in late December 2008. Snow was also reported in the area February 2019, when an unusual amount of snowfall accumulated in low passes in the mountains. That storm system also brought rare snowfall to the Los Angeles area. Heavy graupel was recorded in Malibu Canyon on January 23, 2021. It accumulated as low as 400 feet in elevation.

Fauna
See also: Fauna of the California chaparral and woodlands

The range is host to a variety of wildlife. Common mammals in the range include mule deer, coyotes, bobcats, striped skunks, raccoons, several native bat species, brush rabbits, and many rodents including California voles, western gray squirrels, dusky-footed and desert woodrats, western harvest and California pocket mice, Botta’s pocket gophers, and pacific kangaroo rats.

The mountain lions population is challenged because the Santa Monica Mountains are isolated and not big enough for weaned cubs to find their own territory. The primary cause of the decline is due to a combination of traffic-related mortality, anti-coagulants ingested from human poisoned prey, and attacks by other, more dominant mountain lions.The Wallis Annenberg Wildlife Crossing will bridge the Ventura Freeway which acts as a barrier in the wildlife corridor between the Simi Hills to the north and the Santa Monica Mountains to the south. The National Park Service has recorded a dozen mountain lions struck and killed by motorists on this section of freeway since 2002 when they began a study. Mountain lions approach this particular area and turn back without attempting the hazardous crossing of the freeway as shown by GPS tracking collars fitted to them by the researchers. In 2020, wildlife biologists found the first evidence of physical abnormalities in the isolated population. Newcomers would bring new genetic material into the mountains where the lack of genetic diversity is a serious threat to their long-term survival. It would allow young mountain lions, born in the Santa Monicas, a chance to find a new territory before possibly being killed by one of the more dominant, older males. P-22 was a wild mountain lion residing in Griffith Park in the eastern end of the range.

A three to four year old black bear was captured, examined, and collared in 2023. Designated BB-12, he is probably the only bear in the Santa Monica Mountains National Recreation Area and it is estimated that he had been living there for two years. However, in July 2023, BB-12 was killed while crossing the 101 Freeway. This is not uncommon for animals living in and around the Santa Monica Mountains; a common cause of bobcat and mountain lion fatalities is being struck by vehicles.

Over 380 native bird species call the Santa Monica Mountains home. Abundant native song birds species include the Bushtit, California Scrub Jay, House Finch, Lesser Goldfinch, Cliff Swallow, Red-winged Blackbird, Oak Titmouse, Song Sparrow, California Towhee, Spotted Towhee, House Wren, and Black Phoebe. Red-Tailed Hawks, Sharp-shinned Hawks, Red-shouldered Hawks, Northern Harriers, American Kestrels, Great Horned Owls, and Western Screech-Owls are among common raptors in the area. White-tailed kites, Bald Eagles, Golden Eagles, and Burrowing Owls have also been sighted. In addition to these residential species, many bird species pass through the Santa Monica Mountains as they travel along the Pacific Flyway including Brown Pelicans, Rufous Hummingbirds, Canada Geese, Bonaparte’s Gulls, and Elegant Terns.

Native fish found in the Santa Monica Mountains include tidewater gobies, arroyo chub, and pacific lamprey. Additionally, Malibu creek is home to the southern steelhead trout, which is an endangered species.

Snakes are common but only occasionally seen: the Southern Pacific rattlesnake (the only venomous species), mountain kingsnake, California kingsnake, gopher snake, and garter snake. The mountains are also home to the western fence lizard and the coastal whiptail. The population of red-legged frogs is small and isolated, and was impacted by the Woolsey Fire swept through the area in November 2018.