Red-tailed Black Cockatoos are widely distributed throughout Australia. The south-western population, known as the Forest Red-tailed Black Cockatoo (Calyptorhynchus banksii naso), or Karrak in the Noongar language, is listed as vulnerable, with ‘naso’ referring to its large bill. The Forest Red-tailed Black Cockatoo is the smallest of the five races of Red-tailed Black Cockatoo, weighing 600-610 grams with a length of 53-55 centimetres. The sexes are distinct – males have glossy black plumage with clear scarlet tail panels and a black bill; females have pale greyish bills, yellow-spotted heads and wing coverts and yellow-edged feathers on their belly and breast. This pair of Forest Red-tailed Black Cockatoos is feeding on the seeds from the woody fruits of the Jarrah, Eucalyptus marginata, in Kings Park in the heart of Perth city in Western Australia. The sound of their powerful beaks cracking open the woody Jarrah fruits and seeds is plain to hear.