What are "Tziparim"?
Rashi: This refers to Yisrael. "Yekanenu" is from the root Ken, like "Kan Tzipor" (Devarim 22:6).
Radak: This is a Klal for all birds.
Why does it mention birds nesting there?
Radak: After the cedars are cut, there is benefit from them to roof houses and other buildings, and to make boats. Even wood not used for Melachah, i.e. Zemorah (a sprig of a barren vine - see Yechezkel 15:2) is good for lighting a fire. "Etz ha'Gafen b'Etz ha'Ya'ar Asher Nesativ la'Esh l'Achlah" (ibid., 16) - "Nesativ" is like "Asher Nata" (it is totally via Hashem). Our verse teaches that there is benefit from them even while they grow, even though they are barren. Hashem created small things for the benefit of bigger things. Man is the most honored of the lower beings. Below him are other living beings, below them is vegetation, and below it is inanimate without a Nefesh or motion at all. Cedars and other tall trees are best for birds that fly high to rest on and nest in them.
Why does it mention "Chasidah"?
Radak: It is a big bird; it normally nests in a tall tree, e.g. cedars or Berushim (pine).
Malbim: It commonly dwells in a nest like a house that shields from floods and rain. It chooses Berushim, for its branches are wide and shield from rain.
What is "Beisah"?
Radak: Its nest.
