von Humboldt

While it's too blurry for a positive identification. Two of the ducks, in the lower right-hand side of the photo, are so small they must be green winged teal.

The two birds in the first picture are definitely mallards. The one on the right with the yellow bill is a male in eclipse plumage or possibly a juvenile. The second picture – the three birds in front are mallards as you can clearly see white tails on all of them. I'm unsure of the bird in the back as you cannot see the tale or shape due to the shadows and the bill sure looks solid black. It's probably a female juvenile mallard whose bill is just starting to turn, but I can't eliminate teal. Maybe others can point out something distinctive in that bird to say why it is a mallard.

then they are California.

I believe you can see enough red on the on the forehead to say it's a male red-bellied.

Agree they're mallards. They're going through eclipse plumage and that's probably what's making them look odd to you. Definitely males with that bill color. The bills not as bright now as it will be in the winter and especially spring breeding. The one on the left may be a first year duck as his bill does look pretty drab.

Charlie, I see orange legs and I believe a hint of a speculum, so I'll have to respectfully disagree.

I let them live in my chimneys since I moved out into the country 30 years ago. Watching a large flock of swifts circle and circle a chimney for 10 – 15 minutes then enter the chimney is one of the great sights in birding.

I can't hear your file but those are almost surely just hatched Chimney Swifts. I don't know of any other bird that hangs out in chimneys and this is the time of year for the young to be crying for food. The adults have been in the chimney longer than a couple of weeks but they don't make near as much noise. Go outside and watch the top of the chimney about 30 minutes before sunset until near dark and you should see adult Chimney Swifts entering.

I agree these are juvenile mallards just coming into adult plumage and bill color. Probably all from the same brood due to behavior and apparently being the same age.

Nice gape spot + short eyeline. Very thin white bars on speculum. I agree it's pure mottled duck. The light coloration on the tail is due to wear this time of year and is not a true white like a female mallard would have. Also, in Florida the female can have a bill that is anything from dull olive to indistinguishable from a female mallard.

Most definitely

Agreed, plus it's stocky

I used to fish on a large reservoir where there were several eagles and ospreys. You can always tell them apart when carrying a fish even at a distance. An Osprey carries the fish parallel to the body, an eagle carries their fish perpendicular.

I believe it is only immature sharp-shinned that has the white spots, so that would be my guess.

I just reread Tony's article. I'm going to number the photographs attached to your last post 1-4 from top to bottom. One and two are the same bird. The shadows make colors difficult to discern, but clearly picture 2 identifies it as a male based on Bill color. The eye line is longer than most pure mottled ducks but may be within the spectrum of length for a mottled duck. The gape spot is small but according to Tony that doesn't eliminate pure. What I'm saying is both of these markers indicate hybrid but do not positively confirm it. The tail appears to be black on the upper tail coverts with the butt being white on the side and the bottom. These are the colors of a male mallard, so assuming I'm seeing the correct colors that eliminates any chance of a pure mottled duck. However, it's unusual to not see any curl in the tail. Picture 4- I still say the duck on the right is probably a pure mottled duck, but need a good picture of the head to confirm.