The Ox-breed Viper, one of the world’s largest vipers, is endangered due to habitat loss, illegal harvesting for collecting, and extermination. Researchers study the species in its natural habitat while also conserving the primary tropical rainforest. This knowledge is used in managing the snake in captivity to ensure a venom bank for years to come.
Five Key Facts
In Costa Rica, where 54.2% of the territory is forested, between 500 and 600 snakebite accidents occur each year. Of these, a maximum of three result in death. This low mortality rate is due, in part, to the work of the Clodomiro Picado Institute at the University of Costa Rica, which has been researching and manufacturing antidotes since 1970.
But that’s not all. Each year, Clodomiro distributes approximately 100,000 bottles of antivenom, saving the lives of between 10,000 and 20,000 people, not only in Costa Rica but also in 14 countries with high social vulnerability. Most snakebites occur in poor countries and affect low-income people living in rural areas.
One of the serums used is a mixture of the venoms of the Atlantic and Pacific velvet snake (Bothrops asper), the rattlesnake (Crotalus simus), and the scorpion snake (Lachesis stenophrys). This combination of toxins, known as polyvalent serum, has a cross-reactive effect that covers the poisoning of 17 species of the Viperidae family, such as the Mexican rock snake (Atropoides mexicanus), the golden snake (Bothriechis schlegelii), and the toboba (Porthidium nasutum), among others.
However, the dangers facing the matabuey in Costa Rica today are not only jeopardizing the species’ survival but could also leave thousands of people bitten by snakes in Central America without an antidote.
A poison that saves
Since antivenom reaches low-income populations in countries such as Guatemala, Honduras, El Salvador, Nicaragua, Panama, Colombia, and Ecuador—in these countries, combined, around 6,000 snakebites occur each year—it does not represent an attractive market for pharmaceutical companies, and therefore they show no interest in developing antivenoms or sell them at high prices.
“In the Central American and African countries where our antivenoms are distributed, the market price per bottle is less than $30, while in the United States, each bottle of antivenom similar to ours, produced by private companies, sells for between $800 and $1,000,” says Alberto Alape, director of the Clodomiro Picado Institute since 2012.
According to Alape, in Africa, for example, each bottle of antivenom produced by the French company Sanofi Pasteur sold for close to $200. “It must be taken into account that, to treat severe poisonings, more than 10 bottles are needed,” he adds.
In this sense, the social mandate of the Clodomiro Picado Institute is to manufacture antivenoms that are marketed at a low price in order to provide access to treatment. But this work is being threatened by the decline of the matabuey snake due to habitat loss, illegal harvesting, and the killing of individuals. All of this is leading to the extinction of the species, and with it, the supply of venom for the manufacture of polyvalent serum would be compromised.
“If matabuey venom becomes so scarce that it cannot be included in the mixture, people would be at risk,” warns Greivin Corrales, a researcher at the Clodomiro Picado Institute, and who is in charge of handling venomous snakes at this scientific center’s serpentarium.
The researcher adds: “70% of snake accidents in the country are due to snakebite. It’s very rare for the matabuey to bite a person, but accidents do occur, and the symptoms are more severe, so we definitely need to have serum available; otherwise, the person could die.”
Who is at risk? Those who frequently enter the primary forest, such as Indigenous people and researchers, as well as guides and visitors to a country that depends on nature tourism.
“Not only would the Costa Rican population be missing out on serum, but so would the rest of the Central American countries,” says Corrales. Although they still have venom to work with, they are focusing their efforts on a conservation and reproduction project “that will allow us to resolve the situation in the future.”
In Situ Conservation
The matabuey conservation and reproduction project, carried out by the Clodomiro Picado Institute serpentarium team and the Ríos Tropicales tourism company, consists of two methods. One is to conserve the species in situ, that is, in its natural habitat.
Ríos Tropicales owns a private reserve of 975 hectares of forest, located in Siquirres de Limón, in the Caribbean region of Costa Rica. This reserve protects 10% of the area comprising the Barbilla-Destierro Biological Corridor, which connects with the Talamanca mountain range, where much of the country’s primary forest lies.
Every two months, for three days and two nights, a team of researchers enters the reserve. There, they collect data on matabuey sightings with their respective geographic coordinates, as well as temperature and relative humidity, natural history, and ecological data.
“It’s about translating the data collected in situ into captive management so that the snakes are in such good condition that they can reproduce. Thanks to this, we are able to successfully maintain them in the serpentarium today,” explains Greivin Corrales.
The Clodomiro Picado Institute produces a multipurpose serum, which is a mixture of venoms from the velvet snake, rattlesnake, and matabuey species. Its antivenoms are for human and veterinary use. Photo: Alonso Tenorio / Images in Costa Rica
To date, they have had success with adult matabuey snakes, but the challenge lies with the newborns. “We know almost nothing because it’s very difficult to see them in the forest,” the researcher explains. In the future, and in collaboration with other organizations, the goal is to place microchips in newborns and juveniles to perform telemetry and understand how they move through the forest.
The Ríos Tropicales staff also actively collaborates in the research. They place red flags in the forest when they spot a specimen, which researchers use to take coordinates and later model the species’ distribution in the area.
Maikol Montenegro is one of the guides who enter the forest with the researchers. He admits that at first he was a little afraid of the matabuey, as it is venomous, but that he has been learning more about the species.
“Now I understand the importance of protecting it. This snake lives in its forest areas, and in fact, we are the ones invading its territory, and many people kill it out of ignorance,” says Montenegro.
In fact, according to Kendall Jiménez, head of internal control for the Ríos Tropicales tourism company, the effort to involve guides in data collection enriches their knowledge and improves their tourism service, as they educate visitors on environmental issues.
“What began as a conservation project ended up having a social and cultural impact on the town. The message is now different and has even reached other companies,” says Jiménez.
Just like birdwatchers—who invest in specialized trips to observe a specific bird—herpetologists travel with the goal of spotting a specific reptile or amphibian. Ríos Tropicales is positioning itself as a hot spot for the matabuey viper.
Ex situ conservation
The second method of the matabuey viper conservation project is ex situ, that is, the management of the species in captivity. The goal is that, in about five years, the snakes born and kept under human care will supply venom to the Clodomiro Picado Institute.
“We have to know how to keep the animals in captivity so they’re in good condition and extend their lifespans so they produce the venom that allows us to make antivenoms,” explains Aaron Gomez, also a researcher at the Institute.
The work isn’t easy. If managing snakes in captivity already has its challenges, working with the matabuey is an enormous one. It’s one of the most complicated snake species because they’re very sensitive to stress. They suffer from maladaptation syndrome: they become so stressed that they stop eating and die of starvation.
In this sense, the researchers not only faced the challenge of getting the snake to adapt to captivity but also to do so in such a way that it would reproduce. Currently, the serpentarium has one male and three females, all adults who arrived through donations or confiscations. Two of the females have already managed to reproduce, and the third is expected to do so this year.
Researcher Greivin Corrales used temperature and relative humidity data obtained in the forest to simulate the conditions of the burrow that one of the females would use to lay her eggs. He even built a box that simulated the typical burrow structure so the females could lay their eggs and begin parental care there.
The matabuey enclosures are equipped with sensors—useful for simulating the habitat’s environmental conditions—and cameras for monitoring them. Copulation, egg laying, and subsequent hatching (birth) have been recorded. The newborns are being meticulously monitored.
The next step is to grow these small snakes so they can extract venom in about three to five years. “Our goal is to obtain venom from specimens born in captivity because they are less susceptible to stress compared to wild specimens that are immunosuppressed (commonly known as a decrease in defenses),” explains Corrales.
While stress does not affect the quality of the venom, it does affect the quantity, which is worrying given that the matabuey produces very little compared to other species. In fact, as a general rule, the snakes at the Clodomiro Picado Institute only have venom extracted three times a year. “We avoid stressing them with constant extractions,” emphasizes Corrales.
In the future, the Institute could explore new lines of research related to the venom of the matabuey. “In fact, there is a scientific article that says that if we can make a monovalent Lachesis (matabuey), it would cover all four species present in Latin America. That means that, if we succeed, we could cover the poisoning of all matabueys,” explains Corrales.
Biologically vulnerable
There are four species of matabuey in Latin America. The one that the Clodomiro Picado Institute uses in the manufacture of antivenoms is the Central American matabuey (Lachesis stenophrys), also known as the silent rattlesnake or Javillo’s bocaracá.
This species is the longest viper in the world. Adults average between 1.9 and 2.1 meters, but can reach a maximum length of 2.5 meters. Furthermore, it is the only viper in the region that lays eggs—the other species give birth to live young. It seeks out the burrows of small mammals such as armadillos, moles, and agoutis, where it lays between six and fourteen eggs, each weighing approximately 100 grams. The hatching or hatching success rate is estimated at 90%.
It takes a female five to six years to reach sexual maturity, while other snakes—such as the velvet snake—reach it in half that time (three years) and give birth to between 30 and 60 live young. This makes the matabuey extremely vulnerable: it takes a long time to reach sexu al maturity and doesn’t have as many young,” explains researcher Greivin Corrales.
Additionally, during egg-laying and subsequent parental care, the female has an unstable diet for about six months. “Her exhaustion is so high that this species doesn’t reproduce annually. It’s estimated that it does so every two or three years,” explains the researcher.
Furthermore, in general, it’s very rare for vipers to stay and guard their eggs to protect them from predators. The matabuey does; it remains with them for up to 50 days.
“Its near future, if we don’t take conservation measures, is not at all positive.” “It’s a vulnerable species due to its very specific reproductive biology,” Corrales points out.
Additionally, this species evolved to adapt to its habitat: primary or mature tropical rainforest, and its survival depends on the good health of that ecosystem. This is reflected in its feeding habits: this snake feeds on small prey such as rodents and moles. Its hunting method is to enter the burrows of these mammals and ambush them in their own homes.
“They’ve adapted their digestive tract to digest different small prey, not a large one that would make them vomit. That’s why it’s so long, so it can enter these underground cavities.” There they have shelter, food, and they only need to stick their heads out to drink rainwater,” explains Corrales. And not only that. Unlike other snakes, the matabuey doesn’t need to bask in the sun to speed up its metabolism.
Although it’s a species not currently threatened with extinction, “we are working to include it on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, since neither of the two matabuey species in Costa Rica is on this list,” says Corrales.
If this is achieved, it would provide a boost to the species’ conservation project in the country. On the one hand, it would allow for the alignment of efforts to involve other private and public reserves to counteract the loss of the snake’s habitat, and on the other, it would facilitate the search for funds to finance the research and captive conservation necessary to generate the antivenoms that save the lives of 20,000 people in rural areas of Central America.
