Journalist/author Jan TenBruggencate grew up on Molokai, graduated with a degree in English and journalism from the University of Hawaii, and thereafter made his home on Kauai. TenBruggencate, who celebrates his 72nd birthday Monday, retired in 2007 but remains active in community affairs. He operates the consulting firm Island Strategy LLC, writes the Hawaii science blog RaisingIslands.com and is active in several environmental organizations.

He is also a prolific author on subjects including Hawaiian agriculture, Dutch voyages of discovery in the Pacific and the history of Kauai’s Grove Farm plantation.

TenBruggencate’s newest book, “Menehune Mystery,” explores in fascinating detail the origins of stories about menehune and how the origin stories changed over time. It also includes a retelling of the five oldest written menehune stories, biographies of key menehune storytellers and a detailed examination of everything that is “known” — all the conflicting stories, myths and legends — about menehune.

“Menehune Mystery” was published by Mutual Publishing in September ($13.95 paperback; mutualpublishing.com).

What got you interested in menehune?

I’ve been immersed in the menehune stories from childhood, although it wasn’t nearly as strong a tradition on Molokai, where I was raised, as on Kauai, where I have spent my adult life. The current work started with a fascination with the stonework along Waimea River at the Kikiaola aqueduct, also called Menehune Ditch, and Pe e-o-Kauai.

What’s special about those stones?

Those ditch stones are cut into rectangular shapes, great basalt blocks that are intriguingly similar to the cut and fitted stonework of the Rapa Nui statue foundations. Many people believe the stone ditch is the only example of such architectural stonework in Hawaii, but there are other architectural cut stones in Hawaii — the famous Pohaku Kalai o Umi (the “hewn stones of Umi”). You can see examples fronting the State Archives building in Honolulu.

What did you learn about the origins of menehune stories? Where do they come from?

It is complicated, but there seem to be two fundamental traditions that have been blended into the modern menehune mythology. One is of (the word) menehune as an analog of the Tahitian word for commoners — manahune — full size, nonmagical, working folks. The other is a Kauai history of forest spirit people called melehuna. In the earliest stories, there are distinct Oahu human workers called menehune and Kauai folk called melehuna. By the 1870s, those stories were being blended and supplemented, until by about 1900, they were magical little brown people largely indistinguishable from leprechauns.

Aside from menehune, what do you remember as your most interesting story or the most interesting person you interviewed?

Well, I was a little starstruck when I interviewed Janis Joplin for The Honolulu Advertiser. It was at her Honolulu concert in 1970 just before she died. She was engaging and open as we talked over a bottle of tequila backstage. Then she went onstage and blew the house down.

What are you working on now?

I am working on a couple of book projects on plants important to Pacific cultures, and there’s a nonfiction pirate book.

What do you enjoy doing “for fun” that isn’t related to work?

I’m a reader, a hiker and biker, and I like to paddle and surf canoes.