Estimating the extinction date of the thylacine with mixed certainty data

Area of Science:

• Ecology
• Conservation Biology
• Zoology

Background:

• The thylacine (Thylacinus cynocephalus), Australia's largest marsupial carnivore, was declared extinct in 1936.
• Recent unconfirmed sightings on Cape York Peninsula have fueled speculation about its persistence.

Purpose of the Study:

• To evaluate the likelihood of the thylacine's persistence after its presumed extinction.
• To analyze recent sightings and physical evidence using extinction models.

Main Methods:

• Compiled data including physical evidence and validated/unconfirmed sightings.
• Implemented various extinction models, including a Bayesian approach.
• Modeled valid and invalid sightings as independent processes.

Main Results:

• The most probable extinction date for the thylacine is estimated to be 1940.
• Other models placed the extinction date between 1936 and 1943; the most optimistic estimate was 1956.
• Rediscovery efforts are considered highly unlikely to be successful.

Conclusions:

• The continued survival of the thylacine is implausible based on current extinction theories.
• While searches may not yield results, they can support conservation research in understudied areas.
• Focusing on thylacine rediscovery may be a fruitless endeavor.