We're being monitored!

Walking back along the khlong I noticed these fellows. I am guessing four feet long or so. Some kind of monitor lizard. The first one I saw, I assumed was an escapee from the zoo a few blocks away, but then saw the seocnd one several yards farther along. They keep the khlong near Dusit Park well stocked with fish, so it makes sense these guys would hang out there for the easy dinners. I just have not been around the khlongs enough to know how common the sight is, but I don't think I will wiggle my toes in the water from now on...