If the mutation takes place in a gamete that ends up forming an embryo, the mutation will be passed on to an offspring. This can also occur if the mutation occurs early in an embryos development, and the cell becomes one of the gamete forming cells, the mutation will be passed on to their offspring.
its the Having less deer would increase the mountain lion dependency on rabbits, which would lead to fewer rabbits available for the hawks. but it might be the first one