1983 2 February (continued) ~15/5 hr, still in an alert posture. At about 925m on the Camino Circular Lejoro found another Felis onca scat, this one including dropping plus wads of hair and scattered teeth, all evidently at Tayassu. Went for swim at the waterfall on the way back in, first time this trip. Forgot to mention that when the Lachesis assumed what seemed to be a threatening posture, it flattened (inflated?) the anterior 30-40 cm laterally. A similar lateral flattening is evident in a photo on the dining room bulletin board of this species. 3 February Left ~0800 hr w/Jada Muñoz, station manager. Went to 750m on Sendero El Swamps by way of the Farloop Trail. Found Lachesis muta from yesterday, ~2m from original site, coiled under the more W. of two logs perpendicular to trail. In an oblong coil w/ head resting on one apex - took one picture and didn't disturb it. Saw no new Felis onca tracks in swamp. Went northward on Holdridge Trail then over to Sabalo Esquina Trail and out to ~1750m on it to the Sereciopelo stump. Saw no snakes, but several juvenile Bletherodactylus biporcates, one E. minus, and one E. fitzingeri, all active on trails adjacent litter. This was a warm, sunny morning. After lunch, I went w/ Robin Chagron (Cornell U.)