How will these birds 'inherit' the land?
Radak: They will be there constantly, like a man stands in his inheritance.
What are "Ka'as [v'Kipod v'Yanshuf]"?
Rashi: Kipod is a bird that flies at night (owl).
Rashi (14:23): Kipod is a hedgehog (a kind of Sheretz).
Radak (here and 14:23): They are birds that normally dwell in ruins. Ka'as is called Kik in the Mishnah (according to Shmuel - Shabbos 21a). It is a wild bird found in large coastal cities. Kipod is Kenapod in Arabic, or Tartog in old French. It is always found in a place of water. Yanshuf flies at night, or screams at night. Yanshuf is like Neshef (night).
Malbim: Ka'as and Kipod are wild birds. Yanshuf and Orev are found also in settled areas. They will not inherit; they will dwell there haphazardly. Only wild birds dwell there on a fixed basis.
What is the meaning of "[v'Natah Aleha] Kav Sohu v'Avnei Vohu"?
Rashi: Kav Sohu is the Mishpat of desolation. Avnei Vohu are weights of Din (a judgment of) Churban, like "Even Shelemah" (Devarim 25:16).
Radak: A builder stretches a line and a plumb-line [to ensure that he builds straight]. Here, they will be of Sohu and Vohu, i.e. of destruction, the opposite of building.
Malbim: The verse depicts that Ka'as and Kipod found the country. The line to measure the length and width of the building, and the rocks used to build are of nothingness.