Parakeet (budgerigar?) on lawn near the Pond

Jack and I went over to take a slow walk around the pond, but it was closed due to the Puerto Rican Pride parade.  I'm not really sure why.  We decided to sit on the rocks on the lawn across from the pond, and in flew in someone unusual!  At first I thought maybe it was a molting goldfinch, but it became clear that I had no idea what it was.

Looking it up later, I think it's a budgerigar.  I was thinking a parakeet of some sort.  I did not see a band, and it was not friendly - I didn't actually get very close, but it did not stay around long.  Probably for the best.  Next we saw a pair of Baltimore orioles being chased off by a robin, then a loud ruckus which resulted in a hawk coming over, apparently the blue jays and grackles had been mobbing it.

It was a pretty eventful 10 minutes!  :-)