Costly signalling and the distribution of monumental mounds in Savai‘i and ‘Upolu, Sāmoa

Abstract

ABSTRACTMonumental architecture has long been a focus of archaeological research. The construction of large and elaborate structures is a costly endeavour, which may seem to have little immediate benefit. Costly signalling is one explanation which can be applied to this problem by determining the contexts in which monument construction would carry a selective advantage. This study investigates stone and earthen mounds and platforms from Savai‘i and ‘Upolu in Sāmoa. These are among the most common type of archaeological feature in the landscape, yet targeted research explaining why these costly mounds were built is lacking. One of the primary expectations of costly signalling is that monuments will be located near areas where contested resources are abundant. To test this expectation, a semi‐automated feature identification method was used to identify mounds in LiDAR data, and a model of agricultural productivity was produced to map locations where the cultivation of dryland taro should have been successful. Mounds were found to be preferentially located near areas with high agricultural potential, suggesting that costly signalling could be an explanation for mound construction in Sāmoa, where mounds served to demonstrate resource holding potential and competitive ability.