Western monarch butterflies encompass the monarch populations which migrate and breed primarily west of the Rocky Mountains. Their migratory pattern includes ‘overwintering’, a phase which begins in the late fall and ends in the springtime. During this overwintering period, monarchs will settle along the pacific coast to shelter  and feed off a diversity of nectar plants. When spring arrives, the butterflies will fly inland to breed and lay eggs on milkweed, the monarch host plant.

 
During the 1980’s, Xerces Society documented about 4.5 million western monarch butterflies overwintering along the Pacific coast of California and  Baja Mexico. During the fall of 2020, under 2,000 butterflies were documented in the entirety of California. This catastrophic decline shows that we are in grave danger of losing  the western monarch if we do not act now to protect them. The most significant problems facing the western monarch include habitat loss, pesticide use and climate change. 
 

This past fall, Xerces society documented Gill Tract Farm with the largest monarch overwintering population in the East Bay, and the 5th largest in California. Gill Tract Farm land is unique because it has little to no history of pesticide use or development, which gives the farm an uncommon asset in a state dominated by industrial agriculture. Gill Tract Farm also hosts a diversity of nectar and shelter plants that benefit western monarchs. Because of the alarming  decline of western monarchs, we at the farm are proud of this remarkable finding and are motivated to protect and improve our site!