Most Common Tick Species in Santa Clarita & Valencia

In the SCV, the tick season operates inversely to the region’s hottest weather.

• Peak Activity (Late Fall to Early Spring): Because Santa Clarita experiences hot, arid summers, most local tick species (excluding the indoor-dwelling Brown Dog Tick) go dormant or retreat deep into the leaf litter to survive the dry heat. When the first significant autumn rains arrive and temperatures drop into the 50s and 60s, adult ticks emerge to quest.
• The Winter Threat: Winter and early spring represent the highest risk for encountering adult Ixodes pacificus and Dermacentor species on local trails.

Ixodes pacificus
(Western Black-Legged Tick)

The Western Black-Legged Tick is the most significant tick species in California from a public health perspective, as it is the primary vector for Lyme disease on the West Coast.

• Behavior & Host: During their subadult (nymph) stages, they feed primarily on western fence lizards and small rodents. As adults, they seek larger mammals, including deer, dogs, horses, and humans.
• Local Environment: In the Santa Clarita Valley, they are most frequently encountered in cooler, shaded areas with higher moisture retention, such as oak woodlands or the shaded trails of Placerita Canyon and Towsley Canyon.
• Questing: They exhibit a behavior called “questing,” where they climb to the tips of low-lying vegetation and extend their front legs, waiting to latch onto a passing host.

Dermacentor occidentalis
(Pacific Coast Tick)

This is one of the most widely distributed ticks in California and a very common find on hikers and pets in the SCV.

• Behavior & Host: A three-host tick that feeds on rodents as a subadult and moves to cattle, horses, deer, and humans as an adult.
• Local Environment: The Pacific Coast Tick is highly adapted to the dry, open chaparral that surrounds Valencia and Castaic. They are prevalent in brushy, sun-exposed areas.
• Health Impact: While they are a vector for pathogens like the causal agents of Tularemia and spotted fevers, their involvement in widespread human disease transmission in Los Angeles County remains relatively low; they are primarily considered a significant nuisance pest.

Dermacentor variabilis
(American Dog Tick)

Visually similar to the Pacific Coast tick (brown with grey or silver markings on the dorsal shield), the American Dog Tick is another common resident of Southern California’s open spaces.

• Behavior & Host: As the name suggests, adult American Dog Ticks heavily prefer domestic dogs, though they will readily bite humans.
• Local Environment: They prefer the transition zones between woods and open spaces often exactly where suburban backyards in canyon-adjacent neighborhoods meet the wildland edge.