After we left the cenote we drove north and soon came to some marsh land. We could see a large group of Greater Flamingoes across the water.

We also saw the following birds (Snowy Egrets and 3 Wood Storks) nearby:
I then was able to get a good photo of a Willet:
After we returned to our unit, a group of Greater Flamingoes flew overhead:
During an early evening beach walk in front of the unit, I was able to take a good photo of a Semipalmated Plover.

Here is a table summarizing the day's observations.