Two millennia of seasonal rainfall predictability in the neotropics with repercussions for agricultural societies

<p><span>The reconstruction and analysis of palaeoseasonality from speleothem records remains a notoriously challenging task. Although the seasonal cycle is obscured by noise, dating uncertainties and irregular sampling, its extraction can identify regime transitions and enhance the understanding of long-term climate variability. Shifts in seasonal predictability of hydroclimatic conditions have immediate and serious repercussions for agricultural societies.</span></p><p><span>We present a highly resolved speleothem record (ca. 0.22 years temporal resolution with episodes twice as high) of palaeoseasonality from Yok Balum cave in Belize covering the Common Era (400-2006 CE) and demonstrate how seasonal-scale hydrological variability can be extracted from δ<sup>13</sup>C and δ<sup>18</sup>O isotope records. We employ a Monte-Carlo based framework in which dating uncertainties are transferred into magnitude uncertainty and propagated. Regional historical proxy data enable us to relate climate variability to agricultural disasters throughout the Little Ice Age and population size variability during the Terminal Classic Maya collapse.</span></p><p><span>Spectral analysis reveals the seasonal cycle as well as nonstationary ENSO- and multi-decadal-scale variability. Variations in both the subannual distribution of rainfall and mean average hydroclimate pose limitations on how reliably farmers can predict crop yield. A characterization of year-to-year predictability as well as the complexity of seasonal patterns unconver shifts in the seasonal-scale variability. These are discussed in the context of their implications for rainfall dependent agricultural societies.</span></p>

Severe Cyclones May Have Played a Role in the Maya Collapse

Sediment cores from the Great Blue Hole reveal that a series of extreme storms hit the region after 900. The storms may have irreparably damaged an already stressed Maya population.

FINAL MOMENTS: CONTEXTUALIZING ON-FLOOR ARCHAEOLOGICAL MATERIALS FROM CARACOL, BELIZE

The description and analysis of materials from on-floor deposits that reflect the final activity before site abandonment are key to making a determination as to what happened during the Maya collapse around a.d. 900. On-floor deposits recovered at Caracol, Belize indicate that factors like warfare, the breakdown of the site's market system, and heightened social tensions were in play prior to the abandonment of the site. In an attempt to understand the meaning of these deposits, we first examine why on-floor remains constitute an important data class for archaeology. We next look at the kinds of artifactual materials that are recovered in these deposits and then at the locations and nature of on-floor deposits at Caracol. Finally, we offer our thoughts on what they represent in the broader Maya context.

Community Resilience and Urban Planning during the Ninth-Century Maya Collapse: A Case Study from Actuncan, Belize

To remain in place in the immediate aftermath of the ninth-century Maya collapse, Maya groups employed various resilient strategies. In the absence of divine rulers, groups needed to renegotiate their forms of political authority and to reconsider the legitimizing role of religious institutions. This kind of negotiation happened first at the local level, where individual communities developed varied political and ideological solutions. At the community of Actuncan, located in the lower Mopan River valley of Belize, reorganization took place within the remains of a monumental urban centre built 1000 years before by the site's early rulers. I report on the changing configuration and use of Actuncan's urban landscape during the process of reorganization. These modifications included the construction of a new centre for political gatherings, the dismantling of old administrative buildings constructed by holy lords and the reuse of the site's oldest ritual space. These developments split the city into distinct civic and ritual zones, paralleling the adoption of a new shared rule divorced from cosmological underpinnings. This case study provides an example of how broader societal resilience relies on adaptation at the local level.

An assessment of drought on maize cropping success in ancient Maya lowlands during the last half of the first millennium ce

Drought arising from a shift in intertropical convergence zone in the Yucatán peninsula during the last half of the first millennium is often cited as a determining cause in the collapse of ancient Maya polities. Some Mayanists have postulated that a small change in precipitation might have been sufficient to result in catastrophic cropping failure, with attendant large decline in population. The supporting data for this conjecture are essentially very weak. In particular, paleoclimatologists could provide only qualitative drier or wetter periods. The data resolution has not been at the level of daily or monthly precipitation in ancient times. It is well known in the cropping of maize that the pattern, frequency, and quantity of precipitation, among other things, during the growing period are of paramount importance. Present quantitative assessment suggests that a decrease of the order of 40%, uniformly over a 125-day growing season, from normal precipitation may not have an adverse impact on maize cropping success. This finding presents doubts in the hypothetical climate-based cause of catastrophic decline in population during the period of ‘Maya collapse’.

Permanent Dental Modifications among the Ancient Maya

This chapter explores the dental appearance, health risks, social roles, and procedures related to dental filings and inlays among the ancient Maya. To this end, skeletal data, portraiture, and ethnographic information from the Maya Lowlands were surveyed. The results show that the majority of adult dentitions had been modified during the first millennium AD, many of which emulated the Maya solar sign and sacred wind forces. The initial operation was usually performed in youngsters, although older age groups were subject to the practice as well. Maintenance measures were taken in the form of additional filing and tooth extraction, especially once tooth wear and decay set in. During the heydays of Lowland Maya kingdoms, dental reductions and inlayed materials trace varied regional and local traditions. Past the Maya collapse, during the Postclassic period, tooth modifications turned into a standardized, mostly female practice that was accomplished exclusively by dental filing.