A two-stage population

A seasonal organism has juveniles J and adults A. The next year's counts are Jnext = 4A and Anext = 0.25J + 0.5A. Reproduction occurs only through the stated Jnext term; adults surviving contribute to Anext but are not counted again as juveniles. There is no immigration or density dependence. Initially J = 80 and A = 40. A conservation intervention either doubles juvenile survival from 0.25 to 0.5 (intervention U), or doubles offspring production from 4 to 8 (intervention F); all other parameters remain unchanged.