Victoria south of the Great Dividing Range. Annual rainfall is as little as , with the result that the vegetation is grassland or low woodland rather than forest. River red gum (Eucalyptus camaldulensis) is the dominant native tree on the low slopes and gullies, yellow gum (E. leucoxylon) grows widely throughout the low and middle slopes, and blue gum (E. pseudoglobulus) grows on the rugged upper slopes. Other native trees in the park include red box (E. polyanthemos), grey box (E. microcarpa) & yellow box (E. melliodora), manna gum (E. viminalis), red ironbark (E. tricarpa), cherry ballart (Exocarpos cupressiformis), and silver and black wattle (Acacia dealbata and A.mearnsii). Native low vegetation is sparse and dominated by grasses and saltbushes, with some scrubby areas of snowy mintbush (Prostanthera nivea) and drooping cassinia (Cassinia arcuata). Many introduced plants occur in the You Yangs, some planted deliberately for forestry, including sugar gum (E. cladocalyx), swamp yate (E. occidentalis) and brown mallet (E. astringens), and others that have been introduced accidentally or have invaded the area, for example, boneseed (Chyrsanthemoides monilifera) and bridal creeper (Asparagus asparagoides). The You Yangs are home to more than 200 bird species such as tawny frogmouths, white-naped, white-plumed, New Holland and brown-headed honeyeaters, kookaburras, white-winged choughs, crested shriketits, eastern rosellas, crimson rosellas, purple-crowned lorikeets, sulphur-crested cockatoos, eastern yellow robins, jacky winters and scarlet robins. Mammals living in the park include eastern grey kangaroos, echidnas, swamp wallabies, sugar gliders, brushtail and ringtail possums, and koalas. Koalas in the You Yangs have been studied since 2006. In approximately 28% of the Park they are monitored by a non-intrusive system of nose pattern identification. The entire population was considered to number around 105 in 2017, down 35% from estimated 161 in 2007. The population has been recorded to prefer to roost in river red gum (Eucalyptus camaldulensis): 34% of sightings occur in that species. Four generations of one koala family have been recorded. The nearby Serendip Sanctuary, a Victorian government wildlife research centre, open to the public, has been involved in breeding endangered Victorian wildlife species, such as the Australian bustard and the brolga (Antigone rubicundus). Outdoor activities The foothills to the north of the peaks are home to Ford Australia's proving ground and SSAA's Eagle Park shooting range. There is also a paintball facility next to the SSAA range that is open to both adults and young people. Camping is not