Despite its legendary status in herpetological folklore, surprisingly little is known about the life history of the Green Anaconda Eunectes murinus due to its inaccessible aquatic habitat (Rivas 2000, dissertation University of Tennessee). In the Llanos region of Venezuela, E. murinus coexists with Spectacled Caiman Caiman crocodilus and each species is a predator of the other, but deadly encounters between these powerful predators are rarely observed in the wild and seldom reported. Scientific knowledge thus rests largely on evidence collected after predation events have concluded; for example, Rivas (2000) showed that anacondas consume spectacled caiman by examining stomach contents, but did not witness the predation events themselves. On 14 October 2007, I observed a wild green anaconda of unknown length constricting an adult spectacled caiman, approximately 1.5 m in length, at Hato Masaguaral (67°35’W, 8°34’N), a cattle ranch located along a tributary of the Rio Guárico in central Venezuela. I was alerted to the event by my coworkers, and subsequently took my camera and tripod to the location. Approximately 12 minutes of the event were captured via digital video camcorder (Panasonic GS500). The snake was wrapped around the anterior half of the caiman, and both animals were partially submerged in approximately 0.5 m of water. By the time we arrived, it was clear that the anaconda was the victor of the struggle; the caiman made sporadic lateral movements but was generally docile and seemed to be near death. Small droplets of blood were apparent on unsubmerged portions of the anaconda’s dorsum, indicating that it may have been injured in the fight. Rivas (2004, Herpetol. Rev. 35:67) briefly described an encounter between E. murinus and C. crocodilus, but video footage of such an event is apparently rare.
Rivas, J. A. 2000. Life history of the green anacondas with emphasis on its conservation Biology. Unpublished Ph.D. dissertation at the University of Tennessee, Knoxville. USA.
Rivas, J. A. 2004 Eunectes murinus (green anaconda): Subduing behavior. Herpetological Review 35(1):66~67.