For the Love of Lizards: Meet One of the Smithsonian’s Lizard Experts

For more than fifty years, museum herpetologist George Zug has studied all manner of reptiles and amphibians

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A slender-toed gecko in New Guinea. In 2020, Smithsonian herpetologist George Zug described the diversity of New Guinea’s slender-toed geckos. Shaun Lee, iNaturalist

Few people know more about lizards than George Zug. Over a scientific career that spans more than six decades, the prolific herpetologist has named 54 new species of lizards. He is even the namesake of four new lizard species, including a monitor lizard that is among the rarest reptiles on Earth.

But Zug’s research has never been pigeonholed into one group of animals. Since arriving at the National Museum of Natural History in 1969, Zug has studied a wide swath of cold-blooded creatures including pythons, sea turtles, invasive toads and galloping crocodiles. In 1970, he began studying frog locomotion. To determine the distances of where his live test subjects jumped, he dipped the frogs’ backsides in ink before letting them bounce across a paper track he set up in the museum’s herpetology hallway. In the early 1970s, Loch Ness Monster enthusiasts even sought out Zug’s expert eye to judge a series of images allegedly depicting the mythic beast. (Unsurprisingly, the images were inconclusive).

In 1971, Zug swapped his office in Washington for a research station in Papua New Guinea where he was “surrounded by colleagues and saltwater crocodiles.” As he explored New Guinea’s rugged savannas and mountainous forests, he discovered skinks, geckoes and loads of other lizards. He’s been transfixed by the island’s lizards ever since. In 2020, nearly fifty years after his initial research visit, Zug published a treatise on New Guinea’s slender-toed geckos.
George Zug collects tissue samples while working at a field station in Thailand. George Zug, NMNH

That paper is just one of the more than 130 scientific papers Zug has published over his illustrious career. While he retired in 2007, he still works with the Division of Amphibians and Reptiles collection weekly as an emeritus curator. He is also awaiting the publication of his ninth book—on the biology of tortoises—in early 2024.

In celebration of this week’s World Lizard Day, Smithsonian Voices spoke with Zug to learn more about his introduction to herpetology, doing field work on far flung Pacific islands and his endearing interest in lizards.

The Melanesia slender-toed gecko (Nactus multicarinatus), one of the many lizards Zug has studied over his illustrious career. George Zug, NMNH

How did you first become interested in lizards and other reptiles and amphibians?

When I started out in undergraduate school I knew that I wanted to be in zoology, but I had no real interest in amphibians or reptiles. I was more interested in birds and mammals. Because I grew up in a small rural town in Pennsylvania, I fished and hunted and eventually got into bird watching. So I knew that that's where my interests were.

My first college acceptance was to a forestry school. But as it turned out, I assisted a retired Pennsylvania state forester on the weekends with surveying work who was adamant that I did not go into forestry. So I gave up that career direction.

My mother wanted to ensure I went to college. She wound up getting me into a small religious school, Albright College, whose biology program was basically pre-medical. But Al Schwartz, a young professor there, was into herpetology. He eventually took me to Cuba for my first field work. And my direction was set.

What about lizards in particular captured your research interests?

If you're working in Cuba and the West Indies, the major diversity is in frogs and lizards. Most of the things that you're seeing and catching are going to be frogs and lizards, especially anoles and curly-tailed lizards. On my first trip to Cuba, I happened to catch a legless lizard. And catching a legless lizard is a rare event so my major professor wanted us to report it. So my first published paper was on a legless lizard.

During a 2002 field trip to find lizards in Queensland, Australia, Zug takes a break at a small cafe near a platypus stream to grab a slice of pie. Patricia Zug

What drew you to conducting field work in Papua New Guinea?

The trip there was basically trading offices and houses. The director of a wildlife laboratory there who was studying crocodiles had seen how good the Smithsonian’s library was when it came to resources about crocodilians. When he visited, he simply asked, 'You know anybody who might be interested in trading houses and offices?' And the answer was: ‘well let me go home and ask my wife.’ And fortunately my adventurous wife Pat said ‘Why not?’ So we wound up spending a little over five months there.

Papua New Guinea has several intriguing groups including rainbow skinks and slender-toed geckos. If you look at these geckos’ toes, they are strangely narrow toes. Unlike other geckos, they don't have the expanded toe pads that help them stick to the wall.

In a photo from 1982, Zug sifts through sea turtle shells confiscated by United States custom officials and transferred to the museum’s collection. In addition to his work on frogs and lizards, Zug studied the sea turtles in depth, using clues in their skeletons to determine the ages of these seafarers. Smithsonian Institution

I wanted to examine both of these lizard groups in entirety. While the interest came about by doing field work in New Guinea, it took a long time to wrap these projects up. In addition to examining specimens collected in 1971 and 1972, I mostly worked with museum specimens. Thankfully, I've had the good fortune of being able to visit a lot of museums around the world. I just finished describing the diversity of geckos three years ago.

You have also searched for reptiles in several Pacific Islands. What was doing field work in these remote isles like?

Zug has published several books during his illustrious career at the Smithsonian, including the comprehensive guide to reptiles and amphibians across the Pacific islands. University of California Press

My experience in New Guinea firmed up my interest in the southwest Pacific area. One of my colleagues in the museum’s fish division, Vic Springer, also worked primarily in the Pacific. We were going to Tonga to do field work there in 1984. But Vic happened to see that there was a Typhoon coming. So he quickly loaded all his fishing equipment onto a boat for Fiji and got the gear off the dock a day or two before the typhoon hit.

So we ended up in Fiji where my research centered on the island’s endemic lizards. Fiji only has two or three snakes. But as far as lizards, there's a lot out there.

One of the advantages of working with ichthyologists is that they happen to have boats. And so I would go with them, and they would row me over to the shore of a small island. I just had to hope that they would come back and get me.

I'm still here, so they always came to pick me up. I guess it pays to be friendly to your colleagues.

You’re the namesake of several species, including the Zug’s monitor, Varanus zugorum. What was it like getting a new species named after you?

When one of my colleagues in Germany came to the museum to study our monitor specimens, he stayed with Pat and I. And I think he liked Pat's cooking, so she probably has much or more to do with the name than me. The researcher thanked us by naming the species after us.

The museum’s Varanus zugorum is the holotype specimen on which the entire species’ description is based. It’s also one of the only Zug’s monitor specimens known to science — the lizard has not been seen in its native Indonesia since 1980. Jack Tamisiea, NMNH

I also have a snake, a turtle and two cloacal mites named after me. The cloaca is the back end of the digestive tract. So two of my colleagues were kind enough to think of me when naming these two cloacal parasites!

This conversation has been edited for length and clarity.

Meet a SI-entist: The Smithsonian is so much more than its world-renowned exhibits and artifacts. It is a hub of scientific exploration for hundreds of researchers from around the world. Once a month, we’ll introduce you to a Smithsonian Institution scientist (or SI-entist) and the fascinating work they do behind the scenes at the National Museum of Natural History.

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