Searching for Bushmasters in El Cope



Authored by Stephen Spear

In mid-July, I traveled to Panama to continue our work on our Bushmaster conservation project as part of our strategic program development (see other blog entries). As with the previous trips, I was joined by volunteers and zoo personnel to help me with the search. On this trip, our team included Nick Hanna (an assistant curator at the Audubon Zoo), Mark Herr (an undergraduate at Penn State University), Bryan Hudson (a participant of our first trip and graduate student at Georgia College), and Amy Mattox (Orianne Society summer intern and undergraduate at Wesleyan University). We were headed to the town of El Copé, home of La MICA biological station and the gateway to Parque Nacional Omar Torrijos H., which constitutes some of the best remaining cloud forest in Panama.

Why El Copé? That was certainly on the minds of the immigration personnel as we arrived at the international airport in Panama City. Amy, Bryan and I arrived on the same flight, and as we were showing the officers our passports/immigration cards and told them where we were headed, we got the impression that El Copé does not get very many visitors! We were going because El Copé and the surrounding park are a reptile and amphibian hotspot. Julie Ray, the director of La MICA biological station and one of our collaborators on the project, has found over 80 snake species just in that small area, some which had never been documented there before. And included in this list of snake species is the Central American Bushmaster (Lachesis stenophrys), which of course was ultimately why it was our destination.

Like many areas in Central America, much of the lower areas around towns have been clear cut and are regenerating forests. We don’t expect these areas to be very productive for a sensitive species like a Bushmaster. We wanted to be in the primary forest. As you might guess, the remaining primary forest is in the higher elevations and is not easily accessible (otherwise it wouldn’t still be primary forest!). There is a primitive road leading into the park, but much of the forest is only accessible by foot. And of course, more Bushmasters have been spotted in the part of the forest that is only accessible by foot. So our first two days were filled with multi-hour hikes over steep terrain with trails led by our local guide, Macedonio Perez. I think this is probably the first reason why Bushmasters are so rarely encountered—in general, you have to really, really want to be in their habitat, it’s no country stroll!

Despite extensive searching on these hikes, we did not encounter a Bushmaster, although we did have one moment that got our hearts racing. While exploring the forest in the park, I heard Nick call me over. “Hey Steve, check this out—it looks just like what we see in our zoo exhibits!” Underneath a downed tree was a rounded depression that was drier than the surrounding ground and looked very much like the pattern made by snakes when they coil up. Nick was referring to their own Bushmaster exhibits in which the snakes produce a similar pattern. And if it was indeed a snake, the size of it indicated that it likely would only be one of three species: Bushmaster, Boa Constrictor, or a really big Terciopelo (AKA Fer-de-lance). Needless to say, we then searched the area very intensively, looking in every nook we could find and using our pipe camera to search any nearby holes or refuges. Our search did turn up some smaller snakes in the area including a scorpion-eating snake, Stenorrhina degenhardtii, and Rhadinaea decorata, which is known as the adorned graceful Brown Snake and is related to the Pinewoods Snake of the United States. So it was definitely a snaky place and one we will definitely turn our attention to again.

This was our third focused trip to a site in Central America (either Panama and Costa Rica), and of course we need to actually begin to detect our focal species if we want to understand their ecology and conservation! Each of our trips has been to an area where we know the snakes occur based on local observations. It is not especially surprising that our visual surveys have not located the animal—many people have tried conducting visual surveys without regular success. One of the things that we hoped would unlock the Bushmaster world was by using a pipe camera to search refuges—we know that Bushmasters will use burrows and hollow logs as hiding places. So far I’ve found that while the camera itself works well, most of the burrows we’ve found have been relatively shallow and probably less suitable. A future direction will be to focus our surveys in areas where burrowing mammals like agouti and paca are more prevalent, since we think Bushmasters would be more likely to use their burrows. And we are currently figuring out a strategy to use local personnel to conduct more continuous surveys to increase our odds of detection.

This project is incredibly important to the Orianne Society, as is the sensitivity of Bushmasters. Based on others’ observations, it seems like Bushmasters are very sensitive to disturbance and when there is increased activity, observations no longer occur. We know basically nothing of annual home range or what drives Bushmaster activity. A secretive species like the Bushmaster could be heading toward extinction, and we wouldn’t even know it because they are so rarely seen. We simply don’t know, but it is worth the effort to find out. We’ll keep trying different approaches and find out what finally works. And given the number of other species we see on these expeditions, we are going to learn a great deal about the herpetological diversity in Central America. We already have additional trips to Costa Rica planned this month and in September to continue this work, so stay tuned!