The Swan Coastal Plain north of Perth has become an important feeding area. There, cockatoos also forage in the Gnangara pine plantations, where they feed on the seeds of Monterey pine ("Pinus radiata") and maritime pine ("Pinus pinaster"). Carnaby's black cockatoos have come to depend on these plantations since the early 20th century. Almost two-thirds of the Carnaby's black cockatoos in the Perth–Peel Coastal Plain roost in the Gnangara-Pinjar pine plantation. Other non-native plants that the birds also consume include "Erodium" species, doublegee ("Emex australis") seeds, the fruit of the umbrella tree ("Schefflera actinophylla"), seeds of liquidambar ("Liquidambar styraciflua"), sunflower ("Helianthus annuus"), jacaranda ("Jacaranda mimosifolia"), almond ("Prunus amygdalus"), onion grass ("Romulea rosea"), white cedar ("Melia azedarach"), and hibiscus flowers.