Would like to know more about them than can find in the bird identification books. Any good sources that are more detailed?

...Its not known exactly. There is no way of telling the age of a pelican without banding

Its been estimated that the Brown Pelicans life span can be up to 43 years. However probably less than 30 of hatchlings survive beyond their first year and only 2 of the flocks are older than 10.

few birds die of old age they just run the same gamut of risks year in and year out until they are killed.