Javan spitting cobra (Naja sputatrix). Photo: Christian Alessandro Perez-Martinez (https://alephrocco.com/2018/05/27/javan-spitting-cobra-naja-sputatrix/)

The Species

The Javan spitting cobra (Naja sputatrix) is a large venomous snake in the Elapidae family. Its natural habitat consists mainly of tropical rainforests, though it has been found in a variety of habitat types, including urban areas. In fact, it is the most commonly encountered venomous snake in the city of Jakarta, Indonesia. A diet generalist, N. sputatrix will commonly eat small mammals, birds, frogs, lizards, and other snakes. The main threat facing this species is collection for the snake skin and pet trades. As with other venomous snakes, N. sputatrix will generally only bite people when they attempt to capture or kill them. Unlike many other snakes, however, this species has the ability to rear up and spit venom into an attacker’s eyes in defense. The Javan spitting cobra’s wide distribution, coupled with its potent neurotoxic venom and ability to spit, makes human-snake interactions with this species especially dangerous due to the risk of disability or death.

The Locale

Jakarta is the capital and most populous city in Indonesia, on the island of Java. A relatively flat urban landscape inhabited by over 10 million people, rapid development has spread through the region, reducing the available greenspace to less than 10%. Urban development has forced the 49 species of snakes in Jakarta to adapt to a changing landscape and interact more frequently with humans. With Jakarta’s current, and very difficult goal of increasing greenspace to 30%, human and snake interactions are likely to increase. Fortunately there are various professional and amateur snake catching groups in Jakarta who respond to human-snake conflicts and translocate venomous snakes well away from the city centre. Until recently, it wasn’t clear which snakes were most often encountered, how effective snake catching groups were at reducing human-snake conflict, and whether translocations simply moved the conflicts to rural areas.

Map of the Greater Jakarta Metropolitan Area. Photo credit to Jakarta Map – TravelsFinders.Com ®

The Methods

A 2019 study was initiated by Khoerunisa et al (2021) to investigate human-snake conflict in the Greater Jakarta Metropolitan Area (consisting of Jakarta and five satellite cities, total population of ca. 30 million people) to document diversity of snakes encountered and the methods used to mitigate conflicts. Observational data on snake encounters from 2015 to 2019 were assembled using data collected by 14 different organizations that respond to human-snake conflicts in the city (8 reptile enthousiast communities/groups, 1 pest control company, and 5 fire departments), as well as from online news sources. This was done to pool all information into one database, making it much easier to collectively analyze data held initially by different groups and in different formats.

In total, 656 encounters with snakes were reported in the Greater Jakarta Metropolitan Area, and more than one third were reported in the urban area of Jakarta proper. Overvall, snake encounters were most frequent in densely populated regions compared to sparsely populated areas, possibly due to the presence of more people available to see and interact with snakes, or because snake densities were higher due to an abundance of snake prey (mice and rats). During the study period, and despite reports of 37 species overall, the Javan spitting cobra was one of the most common snakes reported (31% of the 656 snake encounters). Online news sources only reported cases involving Javan spitting cobras or reticulated pythons, likely due to the community recognizing them as dangerous, and therefore more newsworthy. Although venomous snakes were commonly encountered in Jakarta, most encounters were with non-venomous snakes.

Of the 14 organizations involved in the study, 13 captured and translocated snakes as a free service, whereas one (the pest control company) operated for a fee. Although exact proceedures varied, all organizations had access to proper equipment and trained personnel. The reptile enthousiast group members were varied and ranged from school children and students to individuals formally educated in biology, yet they all had a mutual interest in snakes and often shared their knowledge on snake biology, proper handling, and snakebite prevention. In contrast, the fire departments were more focused on responding promptly from a public safety perspective than in providing education, and often contacted reptile enthousiast groups to collect snakes after capture. Large or venomous snakes were typically translocated far from residential areas, while some non-venomous species were released closer to their capture sites. Snake catching organizations provided a reliable alternative to untrained citizens attempting to catch or kill a snake themselves, potentially reducing the rate of snakebites.

Final Thoughts

People in cities such as Jakarta, with large and diverse snake populations, have adopted ways to manage living with venomous snakes while mitigating harm to themselves. Reptile enthusiast groups, regardless of the amount of formal education held by their members, appear to be effective at gaining public trust, improving public perceptions of snakes, and responding to human-snake conflicts. Unfortunately, data is lacking regarding survival and movements of N. sputatrix after translocation, so the impact of current practices on snake populations in Jakarta is undetermined. Based on the results of translocations of venomous snakes elsewhere, however (https://wildlifepreservation.ca/blog/urban-vipers-6-dugites-in-perth-australia/), we suspect that translocated cobras will fare worse than their non-translocated counterparts. In any event, the current study has shown a management practice that can allow humans and venomous snakes to better coexist in urban areas.

Authorship note: This blog post was originally drafted by Remo Boscarino-Gaetano, and edited by Kathleen Woodhouse and Jonathan Choquette.

References
  • Khoerunisa, I., Kusrini, M.D. and Mardiastuti, A. 2021. Diversity of snake rescued from residential areas in Greater Jakarta Metropolitan Area, Indonesia. Media Konservasi. 26(3): 231-238.
  • Muhamad Nor, A.N., Abdul Aziz, H., Nawawi, S.A., Muhammad Jamil, R., Abas, M.A., Hambali, K.A., Yusoff, A.H., Ibrahim, N., Rafaai, N.H., Corstanje, R., et al. 2021. Evolution of Green Space under Rapid Urban Expansion in Southeast Asian Cities. Sustainability. 13: 12024. https://doi.org/10.3390/ su132112024
  • Tan, N.H., Wong, K.Y. and Tan, C.H. 2017. Venomics of Naja sputatrix, the Javan spitting cobra: a short neurotoxin-driven venom needing improved antivenom neutralization. Journal of Proteomics. 157: 18-32.
  • Tempo Media. 2022. Jakarta Council Pessimistic over Having 30% Green Open Space. Retrieved September 29, 2022, from https://en.tempo.co/read/1529054/jakarta-council-pessimistic-over-having-30-green-open-space