Answer:
A scientific hypothesis can be described as a tentative statement which can either proved to be right or wrong through the support of the experiments being performed.
The possible hypothesis for the theory that Wood Thrush decreases are not due to deforestation can be as follows:
'If the population of the Wood Thrush is not affected by deforestation, then the population of the Wood Thrush will remain the same when deforestation occurs in a particular area.'