Habronattus hirsutus is one of four species of western Habronattus forming the tranquillus group whose members are atypical for the genus. While Habronattus spiders are primarily found on the ground H. hirsutus often spends time in the shrub level. In fact I found the individual shown here in the oak leaf litter but he ultimately moved up into the foliage of an adjacent shrub (see “Habitat Image” below). The other three species in the tranquillus group are found almost exclusively in low growing vegetation and seldom on the ground. H. hirsutus‘ varied forms as well as its presence in diverse habitats adds to the species’ uniqueness. It has been collected from sea level to nearly 10,000 feet in a wide range of habitats with some populations looking quite unlike others. Two variable characteristics of adult males are the clypeal coloring and Leg I fringing.
Griswold, 1987; Hedin and Maddison, 2009; Maddison, 1995