Introduction

The ancient lowland Maya civilisation extended over an area of approximately 250,000 km2 in present-day southeastern Mexico, Guatemala, Belize, El Salvador and Honduras. To the south and west of this area, other Mayan language speakers flourished in the highlands of Guatemala and Chiapas, Mexico. Today experts estimate the number of people speaking one of the twenty-four living Mayan languages (the great majority of which are in highland Guatemala) at roughly 6.5 million (for general treatments of the ancient Maya, see Sharer & Traxler 2006; Demarest 2004; McKillop 2004; Houston & Inomata 2009; Martin & Grube 2008). Archaeological estimates of ancient population based on such criteria as the number of possible house mounds multiplied by estimates of occupants based on analogy with Post-Conquest houses run as high as 10 million people in the lowlands overall at the height of the Classic Period civilisation in the 8th century ce (Culbert & Rice 1990). Recognising the hazards of such estimations, the Classic Period lowland Maya were certainly populous and a successful civilisation in their distinctive tropical rainforest setting. In part because of this unusual setting for an ancient civilisation, and in part because in the 9th century ce the civilisation experienced a major collapse in an 80,000 km swath across the southern lowlands, the ancient Maya are popularly identified as “mysterious”. The Maya collapse and its nature, magnitude and causes are energetically debated among experts and to good effect, for while consensus remains elusive, all agree that they are arguing about matters of signal importance to understanding how civilisation in general responds to climate change and might effectively exist in a tropical rainforest setting (Demarest, Rice & Rice 2004).