Search for “Puerto Rican boa” and you’re presented with various snakes with saucer-sized eyes, in bright yellow or green, or alarming articles about it “taking over the island”. Then you realise they’re talking about the host of invasive and illegal boas that found their way there and are messing up the eco-system, not the native Puerto Rican boa, which is brown, non-venomous, and isn’t even top of the food chain. Unfortunately, if a recent snake survey is anything to go by, no one likes this one either!

This is patently unfair, because the Puerto Rican boa has more in common with mammals than some other snakes. For instance, it pops out live young, and sometimes falls foul of other mammals like the neighbourhood cat or mongoose when they fancy a snaky snack. It’s also been seen hanging upside down outside caves like a bat. When a fruit bat flies past, it senses the flapping in the dark and snaps it up, killing it with a breath-squeezing hug. Hey, I didn’t say it mimicked a mammal for good reasons.

It also chose to copy another (unfairly) unpopular animal.

The caves are such a popular dining spot, in fact, that one of them, Cueva Culebrones, is even named after them. Until the other boas arrived, the Puerto Rican version was the biggest predator on the island, and until the Spanish colonists arrived, it happily held on to its fats and oils too. Using them for pain relief has been a thing ever since, and this, coupled with habitat destruction and the aforementioned invaders, has spelt trouble.

Somewhat confusingly, it’s considered endangered locally, but the IUCN Red List of Threatened Species lists it as Least Concern, as it’s pretty widespread in protected areas and seems adaptable to different environments. While it usually hunts at night, it spends its days hiding, basking, or chilling in trees, in forests in the limestone “karst” areas, or even in coffee plantations. Home-hopping (or slithering) is a pretty useful skill, and especially relevant to Puerto Rico of late.

In case you were also in a cave last year, Puerto Rico was hit by not one but two devastating hurricanes in 2017. While Irma hit first, Maria, which struck two weeks later, became the worst natural disaster in the island’s history, with around 3,000 people killed. As well as wrecking buildings and entire landscapes, it flooded caves and wiped out 85% of coffee crops, one of the main products of Puerto Rico. In some areas, these “shade-grown” coffee plantations were partnerships between land owners and conservationists too, with rare species including the Puerto Rican boa sheltering there.

A year later and some of them are on the long road back to normal, but the Puerto Rican boa’s conservation status is as nebulous as ever. If it crams its gullet with freshly-squeezed rats and other pests, it might start to gain favour. I probably wouldn’t hug it, though.


Latin: Chilabothrus inornatus / Epicratus inornatus

What? A brown boa snake

Where? Puerto Rico, mainly in the northwest “karst” areas and caves

How big? Up to 2.2 m / 7.3 ft long

Endangered? Currently Least Concern, but its habitat is disappearing, it’s preyed on by invasive species, and the effects of 2017’s hurricanes are unclear.

Probable motto: Great. I’m already unpopular, and now I’m competing with copycats!

They look…interesting. Do they need my help at all?

There are no specific campaigns at the moment, but the National Wildlife Foundation has them pegged as endangered.

If you want to help regarding the hurricane aftermath, the Red Cross is also accepting donations for humanitarian aid.

Just to prove I’m not fibbing

Chilabothrus inornatus“. No date. IUCN Red List of Threatened Species.

Conners, Deana. 2012. “Boa constrictors are spreading across Puerto Rico“. EarthSky.

Kloer, Phil. 2018. “Aid in the shade“. US Fish and Wildlife Service.

Live Science Staff. 2012. “Boa constrictors invade Puerto Rico“. Live Science.

Natural World. 2017. “A bat hunting boa“. BBC.

Ptáčková, Jana et al. 2016. “Are the aesthetic preferences toward snake species already formed in pre-school aged children?“. European Journal of Developmental Psychology 14(1):16-31.

Puerto Rican Boa.” Beacham’s Guide to the Endangered Species of North America. 4 Nov. 2018.

Puerto Rican Boa“. No date. National Wildlife Foundation.

Puerto Rican Boa“. No date. Utah’s Hogle Zoo.

Puerto Rico bets on a coffee comeback“. 2018. BBC News.

Revell, Liam. 2009. “Boas and bats in western Puerto Rico“. Dechronization.

Sacramento Zoological Society. 2016. “Puerto Rican Boa“. Factsheet.

Featured image credit: “Puerto Rican Boa” by Felix López, US Fish and Wildlife Service