Why did alvar nunez de vaca explore?

Alvar Nunez Cabeza de Vaca was a Spanish explorer who sailed to North America from Spain, leaving in 1527. ... Narvaez did not survive. ... He explored along the Paraguay River

The expedition of 250 to 300 men was led by Panfilo de Narvaez. After surviving a hurricane near Cuba, the expedition landed on the west coast of Florida (near Tampa Bay) in April 1528, claiming the land for Spain.
A series of hurricanes and fights with Native Americans killed many of the crew, and the pilot of the ship sailed to Mexico without the 250 to 300 men. The stranded men hastily made 5 make-shift rafts on which they sailed west, hoping to reach a Spanish settlement in Mexico. Three rafts sank, but the two surviving rafts (carrying 80 men) landed at Galveston Island (off what is now Texas). Narvaez did not survive.

After a very cold winter with very little food, only 15 men survived. In spring, the men traveled west by land, walking along the Colorado River. By 1533, there were only four survivors, including Estevanico, Carranza, Cabeza de Vaca, and Alonso Castillo Maldonado. The men were enslaved for a while by some Indian tribes along the way, and were helped by other tribes. They were the first non-natives to travel in this area of the southwestern North America. Da vaca and his fellow travelers were the first Europeans to see the bison, or American buffalo.

The four men finally reached the Spanish settlement of Culiacan in early 1536 (8 years after being stranded in Florida). Later that year they reached Mexico City, where they were welcomed by the Viceroy Antonio de Mendoza.

After serving as a Mexican territorial governor, Cabeza de Vaca returned to Spain (in 1537) and published an account of his travels, noting the appalling treatment of Indians by the Spanish. His writing encouraged many other Spanish expeditions to the Americas, including those of Hernando de Soto and Francisco Vasquez de Coronado.

In 1540, Cabeza de Vaca was appointed governor of the Spanish settlement on the Rio de la Plata (now called Paraguay). He explored along the Paraguay River (in 1542, he was the first European to see Iguacu Falls). The settlers threw him out of office in 1545, and he was put on trial - he was charged with many offenses, including usurping the authority of the King of Spain. He was found guilty and died soon after.