No it is not necesarily learned. Even among species on earth a lot of behaviors are not learned but inherent. In other words, selection acts on a spectrum of be

No it is not necesarily learned. Even among species on earth a lot of behaviors are not learned but inherent. In other words, selection acts on a spectrum of behaviors and those with some fitness advantage you are likely to see more frequently in the next generation of offspring, extending until lineages of that offspring with that behavior are potentially all there is. A dark forest planet need not learn to be a dark forest planet in the same way an earth colored beetle need not learn to perfectly mask itself against the dirt from a bird; the fitter mutation given the context of the environment won out.