Increasing evidence supports the role of climate change in the disintegration of regional polities in the Maya lowlands at the end of the Classic Period (750–1000 CE). However, the demographic effects of drought remain largely unknown in the absence of Classic Period textual evidence indicating declines in agricultural productivity and population over this broad geographic area. To understand the relationship between climate change and demography, we compare historic records from the Colonial Period (1519–1821 CE) with a subannually resolved climate record for the region. We propose that multiyear droughts across the lowlands resulted in crop failure and severe famines that correlate with intervals of high mortality and migration within two extended dry intervals during the eighteenth century. Changes in population during the Colonial Period support Malthusian models of demography that may be used to conceptualize population dynamics at the end of the Classic Period.

Accurate and high-resolution airborne light detection and ranging (lidar) data have become increasingly important for the discovery and visualization of complete archaeological settlement systems in the Maya Lowlands. We present the results of systematic quantitative analysis of lidar data and ground verification for the major centers of Cahal Pech, Baking Pot, and Lower Dover in the Belize Valley. The Belize Valley is characterized by high density populations living in growing modern towns and villages, and by large-scale agricultural production. This urban environment presents a challenge to reconnaissance efforts since modern construction and agricultural activities have destroyed ancient ruins and created new vegetation patterns. Lidar data was analyzed within a GIS using the Topographic Position Index (TPI) to identify the location of possible archaeological remains. Small-scale, site-level TPI analysis helped identify more detailed archaeological features including small house mounds, terraces, and ditches. Results indicate that lidar data recorded for areas with dense vegetation (e.g., low brush and secondary regrowth) may be less reliable for identification of archaeological remains. The quantitative and qualitative differences between spatial analyses and pedestrian survey results among land cover types indicate that traditional settlement pattern study methods, including pedestrian survey, remain vital to ground-truthing all types of spatial data.

The Terminal Classic Period (AD 750–1000) collapse of lowland Maya social, economic, and political systems has been temporally correlated with severe and extended drought in regional paleoclimate records. Ancient Maya society also experienced a protracted multicentury drought earlier during the end of the Late Preclassic Period (AD 100–300). While some large Preclassic polities declined, many more flourished through the Early Classic. Why were the effects of the Terminal Classic drought more dramatic? What allowed some earlier Maya communities to be more resilient in the face of climate change? Accelerator mass spectrometry radiocarbon dating and stable carbon and nitrogen isotope analyses of human skeletal remains from 50 individuals at the ancient Maya community of Cahal Pech from this critical time period suggest that more diverse diets may have promoted resilience in the face of changing socioecological systems at the end of the Preclassic. During the Late Classic Period (AD 600–800), isotopic data indicate that high-status individuals had a narrow and highly specialized diet, which may have created a more vulnerable socioeconomic system that ultimately disintegrated as a result of anthropogenic landscape degradation and severe drought conditions during the Terminal Classic.

Archaeologists working in the Belize Valley have argued for the persistence of Maya populations from the Classic (AD 300–900) through Postclassic (AD 900–1500) periods since Gordon Willey's groundbreaking settlement survey and excavation work in the 1950s. This is contrary to the trajectory recorded in some parts of the Maya region where there is clear evidence for political disruption and population decline at the end of the Classic period. The argument for continuous Classic to Postclassic occupation in the Belize Valley remains ambiguous due to researchers' reliance on relative ceramic chronologies. This article reports the results of direct accelerator mass spectrometry (AMS) radiocarbon dating of human skeletons (n= 12) from the important center of Baking Pot, Belize, which is thought to provide some of the best ceramic evidence for continuity in the valley. The AMS dates show a long span of mortuary activity between the Middle Preclassic and Late Classic periods (405 cal BC to cal AD 770), with a hiatus in activity during the Early Postclassic (cal AD 900–1200) and subsequent activity in the Late Postclassic (cal AD 1280–1420). These results are not consistent with the idea that Baking Pot was occupied continuously from the Classic through Postclassic periods. This work highlights the need for additional AMS¹⁴C work at Baking Pot and elsewhere to establish absolute chronologies for evaluating the political and demographic collapse of Classic Maya regional centers.