Phidippus adumbratus, sometimes referred to as the California Red Jumping Spider, is a medium‑sized salticid native to the southwestern United States and northern Mexico. Like other members of the genus Phidippus, it is an active daytime hunter with excellent vision, relying on its large anterior eyes to stalk and leap onto prey rather than spinning webs. Its coloration is typically dark with a reddish or orange abdomen, giving it a distinctive look among North American jumping spiders.
 
This species inhabits arid and semi‑arid environments, including chaparral, desert edges, and scrubland vegetation. It is often found on shrubs and low plants where it constructs silk retreats for molting, shelter, and egg‑laying. Males are known to perform visual courtship displays, waving their forelegs and showing off body patterns to attract females.
 
In terms of behavior, P. adumbratus is curious and bold, traits common to jumping spiders. It actively explores its surroundings and responds to movement with keen attention. While not as widely kept in captivity as Phidippus regius or P. audax, it shares similar care requirements: moderate temperatures, good ventilation, and a habitat with vertical climbing surfaces. Its striking coloration and lively personality make it an appealing representative of the diverse salticid fauna of the American Southwest.