Juan Ponce de Leon - Redhead?

It's often stated elsewhere on the internet that the Spanish explorer and conquistador Juan Ponce de Leon was a redhead. I thought I'd have a deeper look into this to see if it's true. Although I haven't come across a definitive reference for the statement, I have found it mentioned in numerous books (modern works that is), often accompanied by the statement that he was 'renowned' or 'well-known' for having red hair. I think this is enough for me to add him, with a degree of certainty, to the redhead canon, although an earlier reference would be nice.

I also found out that Ponce de Leon and his fellow conquistadors were accompanied by a red-haired attack dog named Becerillo, which they used to terrify and attack native Indians. The following quote comes from a book titled Conquest: Cortes, Montezuma, and the Fall of Old Mexico by Hugh Thomas;

The subsequent conquest was simple, marked by the achievements of his dog Becerillo, who, with his terrifying red hair and black eyes, became renowned for his skill in distinguishing by smell between friendly and enemy Indians.

My searches also threw up this quote about a one-eyed, red-haired conquistador. I found this in a book titled Dream State by Diane Roberts.

Panfilo de Narvaez, a red-haired, one-eyed, mean son of Spain, famous for ordering the slaughter of 2,500 native people in Cuba, got the license to run Florida after Juan Ponce de Leon succumbed to that Calusa arrow.

The same book also produced this interesting little titbit about red hair;

The Spanish always get the credit for being the first Europeans to see Florida. They may not have been. The Welsh tell how Madog, a twelfth-century prince, sailed around the Keys up into the Gulf of Mexico. One of my great-uncles said the first Robertses and Tuckers met a blue-eyed, red-haired Welsh-speaking Indian.

:D