Question: What was the father of Vaiva the common Baltic god of?

Related documents: [0]  [DOC] Perkūnas (Lithuanian: "Perkūnas" , Latvian: "Pērkons" or "Pērkon", Old Prussian: "Perkūns", Yotvingian: "Parkuns") was the common Baltic god of thunder, one of the most important deities in the Baltic pantheon. In both Lithuanian and Latvian mythology, he is documented as the god of thunder, rain, mountains, oak trees and the sky. [END] 
[1]  [DOC] Vaiva is a Lithuanian female given name of Baltic origin. It is a shortening of "vaivorykštė" (English rainbow). A rainbow was considered one of the manifestations of the Pagan destiny goddess Laima. Vaiva's father, according to Baltic mythology, is Perkūnas. The name was popularised by V.Krėvė-Mickevičius tale "Perkūnas, Vaiva ir Straublys" written in 1922. [END]  
Answer: thunder
thunder