Frogs? In Los Angeles?

A Red-Winged Blackbird in the Ballona Riparian Corridor
(Image Property of SoCal Earth Science Blog)

Playa Vista Central Park
(Image Property of SoCal Earth Science Blog)

On Saturday, March 2, 2013, I accidentally left my bedroom window open when I went to bed.  After lying in bed for a while, I thought I heard several croaks that were slightly muffled from the sound of the 90 freeway.  I then jumped out of bed and went outside, and to my surprise, I heard a colony of frogs croaking rather hysterically.

I believe that the frogs are residents of either the Ballona Riparian Corridor or Playa Vista Central Park, several blocks south of my house.

Update: I just heard frogs again on 4/30/13.

If anyone has heard these frogs near Playa Vista Central Park, or are knowledgable about what species of frogs are present there, please comment on your experience below.