The main trunk grows up to thick and often resembles a small tree. During its blooming season, March to May, it bursts forth with a mass of showy, bright yellow flowers and green leaves. Giant coreopsis provided shelter and perches for seabirds and land birds, and nesting habitat for many. The prolific seeds provided abundant food for the endemic Anacapa deer mouse, and for many small birds. The island's stands of giant coreopsis, as well as all the other plants of its coastal bluff community, were devastated by sheep grazing in the late 1800s and early 1900s, rabbit browsing in 1910-1950s, and by large-scale destruction of native vegetation associated with facility and road development by the U.S. Coast Guard during construction and manning of the Anacapa Light Station. Only small patches and individuals of native plants remained. "Malacothrix junakii" is a rare species of aster known by the common names Anacapa Island desert-dandelion, Junak's desert dandelion and Junak's malacothrix that is endemic to Anacapa, where it is known from just two occurrences. It occurs in the coastal scrub of the island and was described to science as a new species in 1997. Introduced mammals on Anacapa Island included cats, sheep, rabbits and black rats. Black rats ("Rattus rattus"), also known as ship rats, had a major impact on wildlife on Anacapa Island, including seabirds, such as Scripps's murrelet, reptiles and amphibians, intertidal and terrestrial invertebrates and vegetation. Before an eradication program in 2001–02, more than 96 percent of Scripps's Murrelet nests on Anacapa were attacked by invasive rats. The rats were certainly introduced sometime prior to 1939 (when they were noted by NPS researchers Sumner and Bond), probably in supplies brought onto the island for sheep ranching or building the lighthouse. The National Park Service says there is evidence they were present in 1907. A 1979 study noted that they could have been introduced from a shipwreck such as the SS "Winfield Scott" in 1853. European rabbits were introduced to East Island either as an emergency food supply for lighthouse personnel during World War II or as pets. They were present from the 1940s until at least 1965. No rabbits were recorded from Middle or West Anacapa. Domestic cats were introduced to Anacapa as pets of the fisherman "Frenchy" after whom Frenchy's Cove on West Island is named.