Females tend to disperse from the colony at 8 months, and they reach breeding age at 8.3 months. It is likely that the mothers become intolerant of their daughters, as they reach maturity, prompting their dispersal. The mortality of bell miners prior to breeding age is very high at 93%. The greatest risk is soon after young bell miners leave the nest, when many are preyed upon. Known predators include grey currawong, Australian raven, laughing kookaburra, brown goshawk, copperhead snake, and eastern brown snake. By the time they reach breeding age, the sex ratio is skewed with more surviving males, probably due to higher mortality of the dispersing females. References External links Bell Miner Associated Dieback Photos, audio and video of bell miner from Cornell Lab of Ornithology Recording of bell miner from Graeme Chapman's sound library bell miner Birds of New South Wales Birds of Victoria (Australia) Endemic birds of Australia bell miner Articles containing video clips