FOUND: Two species of lizards, deemed possibly extinct by the IUCN, are photographed for the first time ever in Ecuador

Articles | News | May 2021

A series of expeditions to the western slopes of the Andes in Ecuador have resulted in the first-ever published images of living individuals of two lizard species deemed “possibly extinct” by the International Union for Conservation of Nature (IUCN): the Climbing Whorltail-Iguana (Stenocercus haenschi) and the Orcés’ Blue-Whiptail (Holcosus orcesi). The images confirm the existence of relict populations of each species as well as reveal how attractively colored the reptiles truly are.

First ever image of a male Climbing Whorltail-Iguana (Stenocercus haenschi), a species last spotted by German explorer Richard Haensch at Balzapamba, Ecuador, in 1899. Photo by Alejandro Arteaga.

Adult female of the Climbing Whorltail-Iguana (Stenocercus haenschi), an extremely rare lizard species that remained “lost” for over a century due to its arboreal habits and the loss of its forest habitat. Photo by Alejandro Arteaga.

The information about the rediscoveries was made public as pre-print book chapters of the Reptiles of Ecuador book project. The expeditions were carried out by researchers of institutions: Tropical Herping (TH) and Fundación Jocotoco. The Zoological Society for the Conservation of Species and Populations (ZGAP) funded the Blue Whiptail expedition, whereas conservationist Walter Jennings provided funds for the Climbing Iguana expedition.

Image of the habitat at Balzapamba

Landscape at Balzapamba, type locality of the Climbing Whorltail-Iguana, an area where nearly 79% of the forest cover has been replaced with pastures, crops, and human settlements. Photo by Alejandro Arteaga.

The iguana and the whiptail are the two lizard species considered to be closest to extinction in Ecuador. One was “lost” for over 100 years and the other for 60 years. The last published sighting of a Blue Whiptail was in 1959, although local biologists Ernesto Arbeláez and Jose Manuel Falcón recall seeing the blue lizards in this century, during their childhood years. The Climbing Iguana was last seen in 1899.

Despite intense surveys over the last 30 years, Ecuadorian biologists from various institutions have not been able to locate these these lizards, believed to be extinct. In his 2009 monographic work on Stenocercus of Ecuador, Dr. Torres-Carvajal of PUCE, mentions that S. haenschi was the only species he could not find.

Since 2014, the authors of the Reptiles of Ecuador book began the search for the lost lizards. They carried out nine field trips to Santa Isabel (historical locality of the Blue Whiptail) and five to Balzapamba (historical locality of the Climbing Iguana), but found no living lizards, only vague clues from villagers about the existence of the reptiles. At the same time, in another part of Ecuador, biologist Juan Carlos Sánchez gathered a clue that would prove crucial to the rediscovery of one of the species: he caught a glimpse of a bizarre greenish lizard scurrying away among the rocky bank of Cañar river, in southwestern Ecuador. He also saw lizards on trees in the same general area, but only on those having abundant bromeliads. At the time, he thought these reptiles belonged to another species: Stenocercus carrioni.

In-situ image of an adult female Climbing Whorltail-Iguana (Stenocercus haenschi)

First ever image of a female Climbing Whorltail-Iguana (Stenocercus haenschi). This observation took place along the margins of Cañar river and confirms the presence of the species in an area different from the type locality. Photo by Juan Carlos Sánchez.

Several years later, during the tenth (July 2018) and sixth (March 2021) trip to Santa Isabel and Balzapamba, respectively, did the team members of the Reptiles of Ecuador book find the golden price: true confirmed breathing specimens that proved that neither species was extinct. This was critical, because up until that point, not a single specimen of each species had been secured in their respective type localities since 1959 (for Holcosus orcesi) and 1899 (for Stenocercus haenschi). Without a lizard in hand, there was no way to unequivocally identify any of the previous observations. This is because each lizard can be identified from its closest relatives on the basis of small differences in the number, shape, and arrangement of body scales. Upon careful comparison with the original description of each species, the biologists finally arrived at the conclusion that both lizards still survived.

“Although we explored Balzapamba many times in the past, I felt this time was different,” says Alejandro Arteaga, senior author of the Reptiles of Ecuador book. “It was a bright, sunny morning, perfect for guagsear (the word Ecuadorians use for basking in the sun), so we hopped on the field truck and started cruising a dirt road through a number of haciendas until something caught my attention. It was a bromeliad- and moss-covered tree in the middle a pasture. I thought to myself: boy if I was a Climbing Iguana I would definitely live there. Lo and behold, a green lizard came out running down the tree trunk as though to greet us. I was star struck; this could actually be it. We ran back to the town to secure a big ladder to climb the tree. Once up on the tree, however, I noticed there was a second lizard, and both quickly disappeared from sight. It took a couple of hours of patiently waiting up there until they peeked out again, and with the help and quick reflexes of herpetologists Eric Osterman and María José Quiroz, we finally laid hands on a true Climbing Whorltail-Iguana, and the first male of the species captured after 112 years.”

In-situ image of an adult female Climbing Whorltail-Iguana (Stenocercus haenschi)

In-situ image of a female of the Climbing Whorltail-Iguana (Stenocercus haenschi). This species is strictly arboreal.

With a specimen from the type locality in hand, the biologists could corroborate that the mysterious lizard that had been spotted at Cañar river’s edge belonged to the same species. This was also a major discovery. As it suggested the existence of a second population of this reptile. The discovery of the male unveiled another important fact: males differ from females by having a striking bright green color that becomes more intense when the animal is relaxed, but turns blackish during a stressful situation, a behavior reminiscent of a chameleon’s color change.

First ever image of an adult male Orcés’ Blue-Whiptail (Holcosus orcesi), considered by the IUCN to be the lizard species closest to extinction in Ecuador. Photo by Jose Vieira.

Adult female Orcés’ Blue-Whiptail (Holcosus orcesi). Photo by Jose Vieira.

The finding of the Orcés’ Blue-Whiptail wasn’t quite as fortuitous. “Looking around the historical collection spots for the lizard yielded no trace of these animals,” says Frank Pichardo, who lead one of the expeditions to the type locality of the species. “After searching for hours, we decided to drive to the highest part of the valley in order to find patches of forest. We were guided to a small waterfall where some locals mentioned the existence of a blue-tailed lizard roaming around the houses at the town’s edge. Suddenly, we saw a freshly-killed Blue Whiptail laying on the road, victim to a domestic cat. Upon a closer look, we noticed that the area was surrounded by houses and their cats were everywhere. A local woman directed us to her neighbor who had a lizard pest in her backyard because she did not own house pets. We decided to pay her a visit and then we spotted a lizard disappearing under a pile a wood. Although we never saw the lizard again, this was enough to prove that there were survivors, even if their habitat was reduced to an area no greater than two blocks.”

“Seeing a Blue Whiptail and capturing it are two completely different things,” says biologist Jose Vieira, who continued the series of expeditions to Santa Isabel. “These are extremely quick lizards that can only be seen during hot, sunny days. The few individuals remaining are so skittish that they disappear under thorny shrubs upon the slightest sign of danger, which makes them almost impossible to capture. Thus, we had to rely on creativity and luck. Our best bet wast to set up a system of pitfall traps and drift fences among the shrubs and wait for an individual to fall in. Eureka! This plan allowed us to obtain the first six live individuals of this species.”

The field component of the Orcés’ Blue Whiptail Conservation Project, funded by ZGAP, included interviews with local people, setting up pitfall traps with drift fences, and securing individuals for the conservation program. Photos by Jose Vieira.

Among these six lizards was a male, which unlike females, had a sky blue belly and flanks. A juvenile was also spotted, confirming the belief that only juveniles had bright blue tails, a coloration that is lost as the individuals mature. With these founder stock, the Orcés’ Blue Whiptail Conservation Project was launched, a collaboration between institutions: ZGAP, TH, Jocotoco, and Bioparque AMARU. The project seeks to ensure the future of Holcosus orcesi by reinforcing the single remaining wild population through a re-wilding program in which young lizards are raised in captivity and subsequently released into the wild.

“I was barely a child when for the first time I was able to observe these jewels of nature,” says biologist José Manuel Falcón about the blue whiptail. “At the time, I had no idea that I was in the presence of a species that was about to disappear from many areas in the dry valley of Yunguilla. They were so abundant and easy to observe, but another species (Stenocercus rhodomelas) began to become more frequent and gain ground while it became increasingly difficult to find whiptails. For years I searched without success, until in 2017, a friend sent me a photograph of the blue-tailed lizard in another location in the same valley. That photograph proved that the lizards still existed and, after several unsuccessful searches, finally in July 2019, among the grasslands of the same site, I could see a female of that living jewel.”

Although it is now clear that there are still surviving populations of both the Blue Whiptail and the Climbing Iguana, these species are unlikely to fall out of the Critically Endangered IUCN category in the near-term future, which means that both species are considered to be facing imminent risk of extinction. Even despite the recent discoveries, a review of their current status suggests that there is no more than 77.4 km2 and 371 km2 of suitable habitat remaining for for Holcosus orcesi and Stenocercus haenschi, respectively. Furthermore, the habitat fragments where the species survive are under continuing pressure from deforestation, predation by exotic species (including cats, dogs, and chickens), and poaching.

Image showing the current landscape at Santa Isabel

The only confirmed population of Blue Whiptails survives in a small (~2.7 km2) habitat fragment under continuing pressure from human development, predation by exotic species, and poaching. Photo by Jose Vieira.

The establishment of a captive breeding program is an urgent, desperate measure to keep some Orcés’Blue Whiptails alive. In the long-term, only the creation of a properly managed conservation area free from deforestation and exotic predators will stop the species from extinction. In the case of the Blue Whiptail, the most concrete course of conservation action is to help Fundación Jocotoco expand the limits of its Yunguilla Reserve, which is adjacent to, but currently does not protect, the only remaining population of the Critically Endangered lizard.

The Climbing Iguana’s fate appears more uncertain. There are no private or national conservation areas anywhere near the relict populations, and one of these is effectively under the mercy of the environmental effects of a new hydroelectric project. With major support, however, the hacienda where the Climbing Iguana was found could effectively be turned into a private conservation area.

Today, you can play a major role in the long-term survival of the two lizards by supporting the Fundación Jocotoco’s campaign to expand its system of reserves in southern Ecuador.