On this May evening, many American pikas were making "long calls" in an amphitheater-shaped talus slope. Their combined calls filled the talus slopes with a grand concert. Apparently, male American pikas perform this long-call song during the breeding season presumably to attract females. Some researchers assume this "long call" is made almost exclusively by male pikas to define and signal their territory, or they may make this call if another pika has violated a territory