All this strikes a chord with me, because my original field was in ethology, or animal behaviour, and the study of primate behavior was in its infancy when I was at university.(t)he behavior described is even more familiar to the scientist. Local villagers and Western observers relate the yeti's behavior that are easily recognized as displacement conflicts, aggressive posturing, and threat displays - patterns which scientists have recently found to be typical of wild ape behavior. The reports seem too good, too accurate, not to be true.
Shortly before dawn the next morning, Dr. Emery climbed out out of our tent. He called excitedly. There, beside the trail we had made for our tents, was a new set of footprints. While we were sleeping, a creature had approached our camp and walked directly between our tents. The Sherpas identified the tracks without question as yeti footprints.We immediately made a full photographic record of the prints before the sun touched them. Like the conditions Shipton had encountered, the surface consisted of crystalline snow, excellent for displaying the prints. These conditions were localized to our camp area, and were the result of the effects produced on the depression by the sun and the winds of the previous days. The prints were clearest in the middle of the depression, directly beside our trail, where some ten to fifteen prints, both left and right feet, revealed the details of the toes and the general morphology of the creature's foot. Some of the right footprints were actually on our previous trail, making them difficult to interpret; other prints of the right foot were distinct.The prints measured approximately nine inches by four and three quarters inches wide [23 x 12 cm]. The stride, or distance between individual prints, was surprisingly short, often less than one foot, and it appeared that the creature had used a slow, cautious walk along this section. The prints showed a short, broad, opposable hallux, an asymmetrical arrangement of the four remaining toes, and a wide, rounded heel. These features were present in all the prints made on firm snow, and we were impressed with their close resemblance to Shipton's prints.We then proceeded to explore the rest of the trail left by the creature. By the direction of the toes on the clear footprints, I determined that the creature had come up the north slope. I investigated these prints first, following the trail back down the slope. Because the north slope received less sun, it was covered with very deep snow, and the tracks consisted of large punch holes in the snow, revealing little detail. I descended several hundred yards, but the heavy snow made walking impossible, and I was forced to cling to the slope with my hands; the creature must have been exceptionally strong to ascend this slope in these conditions. From a vantage point, I could look down the trail, which continued towards the bottom of the valley in a direction generally perpendicular to the slope, but there seemed little advantage in climbing farther down, and I returned to the top of the ridge.