major plant communities covering approximately equal acreage within the park. These are coastal sage scrub, chaparral, and annual grassland. Chaparral often co-exists with sage scrub on the hills and slopes of the park; mostly in the southern extreme of the park. The grassland covers the valley floor, with riparian zones along the park's perennial streams. The park, a designated wildlife sanctuary, protects the habitat of 137 species of nesting and migratory birds. Plants The Aliso Canyon bottom is seasonal grassland, which flourishes in spring and diminishes by late summer or fall. The park protects habitat for a number of sensitive plant species, including many-stemmed dudleya, Pomona rattleweed, Orange County Turkish rugging, Palmer's grapplinghook, aphanisma, Laguna Beach dudleya, scrub oak, western dichondra, hummingbird sage, ocean spray, and crown-beard. Oak and sycamore are found in Wood Canyon, and marshes and grassy wetlands are found along Aliso Creek. Native grassland ecosystems in the less visited south-western portion of the park are considered largely intact. Animals The park is one of the largest sanctuaries in coastal Orange County for mammals such as coyotes and bobcats. Several sensitive bird, small mammal, and reptile species find refuge in the park, including California gnatcatcher, pond turtle, San Diego horned lizard, orange-throated whiptail, Pacific pocket mouse, great egret, white-tailed kite, northern harrier, sharp-shinned hawk, Cooper's hawk, ferruginous hawk, cactus wren, yellow warbler, and yellow-breasted chat. Up to five bald eagles have been counted in Aliso Canyon, and peregrine falcons have been sighted flying along the canyon walls. Fish Aliso Creek was formerly a major steelhead stream. Dam construction, upstream channelization, pollution, invasive plant species such as giant reed, as well as severe erosion problems that have in some places undermined the Aliso Creek Trail, have essentially eliminated steelhead with only occasional anecdotal sightings. Near the mouth, there was also a large population of tidewater goby (an endemic species to California) which have largely disappeared with human development. Carp of up to 18 inches (1.5 feet, 45 cm) have been taken from the creek; they are among the few fish species that thrive in the warm, silty and nutrient-rich waters. Environmental issues Among the most long-running problems afflicting Aliso and Wood Canyons is the presence of invasive species, many introduced by former ranching activities, and later, exotic ornamental plants imported for gardens. Plants such as giant reed (Arundo donax) and pampas grass crowd out native vegetation and provide less