While Tammy and I explored Potter Marsh, we noticed two different raptors that appeared to have made the place their home: Northern Harrier and Merlin.
While driving from the opposite (non-birdy, very flowery, tick-infested) side of the marsh, we noticed a Northern Harrier perched on a post that was smack in the middle of the whole marsh. Several times after that, as we roamed about the boardwalk, we would see the flash of the Harrier's white rump as it cruised over the marsh looking for something tasty. I don't usually try to age birds, mainly because such efforts on my part usually end up in frustration, but my picture and the drawings for a juvenile Northern Harrier in Big Sibley seem to have a few things in common.
The other raptor was a small bird that I first identified as a Sharp-shinned Hawk. But I also knew that I was not super familiar with that species, so I asked another birder who was ahead of me on the boardwalk. Their answer was Merlin. Hmmm. At that point I had no photo because the bird was simply too far away. I made a mental note - that bird may be one that goes unidentified. It seemed, however, that this smallish raptor was "making the rounds", and it would reappear from time to time, usually being pursued by a self-appointed posse of Black-billed Magpies. When the bird decided to perch on an old root ball from some long toppled tree (still several yards away but now easily within the reach of my camera), I snapped a few photos in the hopes of ensuring that an identification could be made later. My review of the photo and a couple of field guides led me to conclude that it was indeed a Merlin. Here he is, fanning his tail, keeping an eye out for that posse I mentioned.