The bushmaster species inhabit our planet’s Western Hemisphere and their genus comprises the world’s largest vipers, with the South American Bushmaster (Lachesis muta) holding the record with lengths passing three meters. South American bushmasters are divided into two subspecies, being Lachesis muta muta and Lachesis muta rhombeata, a subspecies whose range is restricted to east-central Brazil’s Atlantic Forest. Another South American species is the Chocoan Bushmaster (Lachesis acrochorda) which inhabits the forests from southern Panama, into Colombia and down to Ecuador. Costa Rica is home to two species of bushmasters, the Central American Bushmaster (Lachesis stenophrys), with a distribution from eastern Nicaragua to Central Panama, and the Black-headed Bushmaster (Lachesis melanocephala), of which the latter has the smallest distribution range of all Lachesis species. Therefore, our organization, named Plato Negro Ecology and Conservation, are making major e forts to study and protect this emblematic species from extinction.
Presentation of the Plato Negro
The Black-headed Bushmaster is the rarest species of bushmaster and can only be found in the central and southern Pacific region of Costa Rica, except reports of a few individuals found in Panama. The Spanish local name is Plato Negro meaning ‘Black Plate’, the scientific name was derived from the Greek Lachesis meaning ‘the personalization of fate’, melanos means ‘black’ and cephalo is ‘head’. Allthough the total length of these snakes doesn’t exceed 2m 30cm, it is still one of the countries’ longest pitvipers, only outcompeted by the Central American Bushmaster or Matabuey (Lachesis stenophrys), meaning ox killer, that inhabits the Atlantic slopes of Costa Rica. Bushmasters are unique because they are the only New World Viper species known to be oviparous or egg layers, the eggs are laid in abandoned mammal burrows, which are guarded by the female for about three months. In some South American countries, they are called pineapple snakes, referring to their rugged keeled scales that are characteristic for them. They prove useful to them in courtship, where the males even turn on their backs to rub their scales against those of the females. Males tend to grow larger than females, which seems to be common in snake species where males perform ritual combat in the breeding season. Male combat might be a stimulus for a female bushmaster to mate, but publications on the captive reproduction of this species have also shown it is no necessity. These combats can be compared with a wrestling competition where the strongest opponent tries to push down the weaker one while keeping their heads up facing the forest canopy. These fights can go on for many hours and although these pitvipers have significantly large fangs and venom glands packed with lethal toxins, the use of this weaponry is never an option. In our experience, snakes are very reluctant to strike even when threatened and will only bite when left with no choice, their venom serves them better for immobilizing and digesting prey, like the rodents on which they feed. The term pitvipers refers to the presence of a loreal pit, located between the nostrils and the eyes, this serves as a thermo-receptor or infrared organ, a heat detecting organ that doesn’t occur in European or African viper species. Ophidian accidents or snakebites with/ from Black-headed Bushmasters are rare, even when encountered we witnessed a rather placid behavior, nevertheless if envenomation occurs it is a life[1]threatening situation for the person bitten. Fact is that sightings of them are a rarity, them being mostly nocturnal and prefer a hidden life deep in the primary tropical rainforest, a habitat that got scarce due to deforestation.
Research and Conservation
In 2012 Dr. Stephen Spear, co-chair of the IUCN Viper Specialist Group, Costa Rican biologist Guido Saborio and Costa Rican herpetologist Marcello Carvajal, formed a group to begin to study the natural history of the Black-headed Bushmaster. After many surveys looking for this illusive species in the rainforests of the Osa Peninsula, it is only in 2015 they had their first wild encounter with this majestic pitviper. The location of the find was at Ecoturistico La Tarde, a rural ecolodge with a private reserve bordering Corcovado National Park. The reptile drew the attention of many Costa Rican people and soon tourists from all over the world came to admire the snake in her natural habitat. It is here that the first telemetry survey was conducted on the Black-headed Bushmaster, at this time I (author) joined the project and a life-time dream started to come true, one of the reasons I chose to come to Costa Rica was being part of the conservation of my favorite serpent along with studying its natural history. At that time, we didn’t have a veterinarian available to place the radio-transmitter under the skin of the snake, so we decided to place the device on the skin of the animal. For several months her movements were followed daily, especially by Marcello and Eduardo Castro, the owner of the eco lodge, and the fee for allowing tourists to see the snake hereby contributed to the costs of the logistics. This conservation strategy might be crucial to the protection of rare big venomous snakes, since locals normally would kill these animals, it is very important they can benefit from keeping them alive. Dispelling myths about the Plato Negro, is another very important topic to cover, most of the people see them as large aggressive venomous snakes, but by sharing our experiences interacting with the species and involving local communities in our research, these false accusations quickly change. During the telemetry study renowned Costa Rican botanist Reinaldo Aguilar Fernández joined our organization and with him a detailed description of the vegetation of the Black-headed Bushmaster’s habitat is conducted. After several months the snake with the transmitter shed its skin, snakes shed their old skins when growing and this process called ‘ecdysis’ continues throughout their life, and with this the device was thrown o f also. At least we had a glimpse of the animal’s life cycle, a lot of new discoveries and data was collected, data that soon will be published in a scientific publication. Our search for other bushmasters continues and our research team got strengthened by dog trainer Carlos Orozco and his Belgian Malinois with the appropriate name ‘Viper’, this dog is especially trained to find wild bushmasters. In 2019 herpetologist and ecologist Dr. Kimberly Andrews, was welcomed in the organization, working for the University of Georgia, she studied spatial ecology for reptiles for over 20 years and is devising innovative field techniques that will refine our understanding of the snakes’ habitat and behaviors. Being able to track the bushmasters for a much longer period, the radio transmitters are best placed inside the snakes, that is why we invited Dr. Ana Maria Torres Mejia to join our group, she is a Colombian biologist and veterinarian that studied conservation medicine, she also is the director of Asomacao, an organization that works on the conservation of the scarlet macaw (Ara macao) in Costa Rica
The Future
Costa Rica seems to be one of the only countries where the forest cover is increasing, thanks to many conservation eforts from the government as well as private initiatives. As an organization, we promote to protect what is left of the natural habitat of the Black-headed Bushmaster, but also restore already damaged ecosystems, true reforestation projects with local flora. For this it is important as far as is practicable to study the ecology of this magnificent pitviper, by doing more telemetry and surveys in the forest, often these studies include camping at the research sites. Since sightings of this species are infrequent within its distribution range, our plan for conservation includes a captive breeding program, which we find essential for the survival of this endangered species. The biggest challenge in all of this is that people tend to be more attracted to charismatic animals like sloths, monkeys and macaws, snakes in most parts of the world still provoke more fear than fascination. Having had the honor interacting and manipulating several wild individuals of Plato Negros during our research, we certainly can reject the word ‘infamous’ at this article’s title, since there was not one occasion were, these so called ‘aggressive’ snakes, even made the slightest attempt to strike at us. Looking at social media, people are claiming having seen the Plato Negro, steal and post photographs of the more fortunate, something we do not agree with, but we can see this in a positive way and conclude that the public interest in the species is growing. Educating and involving local communities is the key to conservation, making people more aware of the role of these creatures in the ecosystem, showing them once and for all that snakes are not the representation of the devil.
