In 1939, a collector described the San Clemente Island paintbrush as common on the lower slope of bluffs on the southeast coast of the island [2]. By 1963, it was described as “occasional on the southeast coast and rare on canyon-sides elsewhere” [2]. By 1978 few plants could be found [2]. A survey of the entire island conducted in 1979 found a total of 450 plants [2]. The decrease in the number of San Clemente Island paintbrush was largely due to grazing and trampling by feral goats and pigs [1]. Although livestock from early ranching on the island had been removed prior to the establishment of a military training facility in the 1930s, some feral goats and pigs remained and their populations increased dramatically [4]. The paintbrush plants that survived the presence of these animals were often located on steep cliff faces where they couldn’t be reached [1].

Programs to eradicate feral animals on the island were initiated in 1962 [4]. These efforts were unsuccessful, however, until renewed efforts in the 1980s led to the extirpation of feral animals on the island in 1992 [4]. Following the elimination of these animals, paintbrush populations began to increase and expand [4]. In 1996 and 1997, 77 populations of San Clemente Island paintbrush were mapped on the island, totaling more than 3,500 plants [5]. Recent mapping efforts indicate continued progress towards recovery [6]. Since 1997, a dramatic increase in the number of paintbrush plants has taken place and the paintbrush has colonized new areas of the island [6].

[1] Center for Plant Conservation. CPC National Collection Plant Profile: Castilleja grisea. Website <http://www.centerforplantconservation.org/ASP/CPC_ViewProfile.asp?CPCNum=817> accessed January, 2005.
[2] Mohlenbrock, R.H. 1983. Where Have All the Wildflowers Gone? A Region-by-Region Guide to Threatened or Endangered U.S. Wildflowers. Macmillan Publishing Co. Inc. NY.
[3] Endangered Species Information System. 1996. Fish and Wildlife Information Exchange, VA Tech. San Clemente Island Indian Paintbrush. Website <http://fwie.fw.vt.edu/WWW/esis/lists/e701029.htm> accessed January, 2005.
[4] Helenurm, K., R West, and S.J. Burckhalter. 2005. Allozyme Variation in the Endangered Insular Endemic Castilleja grisea. Annals of Botany 95(7):1221-1227.
[5] Junak S.A. and D.H. Wilken. 1998. Sensitive plant status survey, Naval Auxiliary Landing Field, San Clemente Island, California. Santa Barbara, CA: Santa Barbara Botanic Garden.
[6] Junak, S.A. 2005. Personal communication with Steven Junak, Santa Barbara Botanic Gardens.