A single observation associated with the explorations of Juan Ponce de Leon, is an event from 500 years ago that is a unique event in the historic ornithology for northern America.
After departing from Puerto Rico, and seemingly in search of a "fountain of youth," de Leon and his mates landed on an unknown shore on March 27, 1513. The place was named "La Florida" because it was the date of the festival "el Dia de Pascua Florida de Resurreccion" and the place was claimed for the Spanish realm.
Continued along the expedition, traveling by sea, went southward along the eastern coast of Florida, and then westward along the many keys at its southern extent. By June they were along the southern extent of the west coast of this foreboding land, where there were troubles with the local residents. Mayhem and death occurred at a place called Isla de Matanza.
A profound date of significance, though probably trivial in the overall chronicles of this voyage, was June 21. The sailors reached a particular island westward of the keys. The group landed, took 160 turtles in a single night, and so they named the place Tortugas, which is the Spanish language term for turtle.
An account for the voyage, though very limited, indicates that pelicans and other abundant birds were also killed to help replenish the mens food supply, during their visit of a few days.
"reached the chain of islets which they named Tortugas because in a short time of the night they took, in one of these islands, a hundred and seventy turtles, and might have taken many more if they wished, and also they took fourteen seals, and there were killed many pelicans and other birds, of which there were five thousand." — Antonio de Herrera
The pelicans were the Brown Pelican, a prominent species of the region, even now during modern times.
This is apparently the first known actual date of occurrence for this species in North America. The chronicles do not indicate that a brown pelican, also known as the alcatraz according to later narratives, was seen on this particular date. It is obvious that Spaniards were at the island on this date, and pelicans were taken during the visit. They may have been present on the 21st, and perhaps being residents, on the subsequent dates.
The value of 5,000 indicated was apparently the number of birds present, not the number killed.
Any previous records of this species for the same geographic area are associated with studies which considered bones remnants found at archeological sites.
There are at least nine occurrence records from 1523 to 1725, mostly in the Caribbean region. Only two of these narrative reports provide enough details so that a particular month can be designated.
The next known date of particular occurrence is June 5, 1736 at St Augustine, Florida.
Interestingly, this locality is one of the three to four places, and perhaps, depending upon studies by aficionados of de Leon, the place where he first set foot upon the land he called Florida.
John Hawkins would visit the Tortugas on July 5, 1565, also noting a great number of birds. The voyage account said: "where the captaine went in with his pinnesse, and found such a number of birds, that in halfe an houre he laded her with them; and if they had beene ten boats more, they might have done the like."