Yes

It’s obvious that Rancor knows about this stuff a lot more than you and may have an idea how to go about solving this problem. So it would be stupid not to ask him about it.

“You see, everything I told you is pure speculation, there is a very good chance the real reason for their erratic behavior is completely different. So, I cannot offer you a concrete solution to the problem without knowing the actual cause. What I can do is give you a general idea about it if the reason turns out to be what I suspect. Will that do?”

“Yes, that would be very helpful, thank you” is your reply.

“Okay, if the harpies are affected by magic and their mating urge have become permanent. Which I don’t really think is the case, because harpies are magical creatures, they have really strong resistance to the corrupting or augmenting effect of magic, on top of that, they are living in the mountains for a long time and are attuned to the magic of the place. If it turns out that they are being affected by the magic, I think there might be some new source of magic in there and it has gotten past the harpies’ natural resistance. In that case, the solution would be to remove or neutralize the new source of magic and cleanse the harpies of the effect.” He pauses for a moment before continuing,

“And if the reason is the more likely of the two, impotence of the men around the harpies’ territory and their inability to get pregnant, the solution is pretty simple, you have to find a way to get them pregnant, that will subside their heat, and they will return to normalcy for the time being, until their next mating season starts, then they will start looking for mates again and if they fail to get pregnant again, they will start acting like they are acting now.” Rancor finishes his theory.

“I told you he has an interesting theory,” says Balthor, “So, now that you have the necessary information what are you gonna do?” he asks you.