Answer:
The introduction of competitive species such as wild dogs, foreign diseases including mange, and extensive habitat destruction
Step-by-step explanation:
It is estimated that at least 3,500 thylacines were killed through human hunting between 1830 and the 1920s. The introduction of competitive species such as wild dogs, foreign diseases including mange, and extensive habitat destruction also greatly contributed to thylacine population losses. The Thylacine became extinct on the Australian mainland not less than 2000 years ago. Its decline and extinction in Tasmania was probably hastened by the introduction of dogs, but appears mainly due to direct human persecution as an alleged pest.