Darcy Bird

• Doctor of Philosophy
• Post-Doctoral Associate at University of Florida

Archaeologists increasingly use large radiocarbon databases to model prehistoric human demography (also termed paleo-demography). Numerous independent projects, funded over the past decade, have assembled such databases from multiple regions of the world. These data provide unprecedented potential for comparative research on human population ecolog...

Abrupt and rapid changes in human societies are among the most exciting population phenomena. Human populations tend to show rapid expansions from low to high population density along with increased social complexity in just a few generations. Such demographic transitions appear as a remarkable feature of Homo sapiens population dynamics, most like...

Global services like navigation, communication, and Earth observation have increased dramatically in the 21st century due to advances in outer space industries. But as orbits become increasingly crowded with both satellites and inevitable space debris pollution, continued operations become endangered by the heightened risks of debris collisions in...

Over the last 12,000 y, human populations have expanded and transformed critical earth systems. Yet, a key unresolved question in the environmental and social sciences remains: Why did human populations grow and, sometimes, decline in the first place? Our research builds on 20 y of archaeological research studying the deep time dynamics of human po...

Controversies exist regarding the extent of past human influence on terrestrial ecosystems and the relative importance of human versus climatic factors in shaping Holocene vegetation. However, there has been no systematic examination of these issues at a global scale. Here we integrate palaeoecological, archaeological, and palaeoclimate data to ass...

Persistent differences in wealth and power among prehispanic Pueblo societies are visible from the late AD 800s through the late 1200s, after which large portions of the northern US Southwest were depopulated. In this paper we measure these differences in wealth using Gini coefficients based on house size, and show that high Ginis (large wealth dif...

A brief explanation of paleodemographic proxies, radiocarbon, and p3k14c.

Collective computation is the process by which groups store and share information to arrive at decisions for collective behavior. How societies engage in effective collective computation depends partly on their scale. Social arrangements and technologies that work for small- and mid-scale societies are inadequate for dealing effectively with the mu...

Explaining the stability of human populations provides knowledge for understanding the resilience of human societies to environmental change. Here, we use archaeological radiocarbon records to evaluate a hypothesis drawn from resilience thinking that may explain the stability of human populations: Faced with long-term increases in population densit...

Significance Collapse of civilizations remains one of the most enigmatic phenomena in human history. In this paper we provide quantitative evidence that loss of resilience systematically preceded collapses. We take advantage of unique time series documenting both construction activity and climate conditions for pre-Columbian societies of the southw...

When the environment changes, sedentary people choose whether to stay and invest more in their current adaptive strategy, or abandon their land and residence to go somewhere with greater opportunities. For a well-understood portion of the upland US Southwest we ask: when the maize niche shrinks, do people continue investing in the landscape (displa...

The northern American Southwest provides one of the most well-documented cases of human population growth and decline in the world. The geographic extent of this decline in North America is unknown owing to the lack of high-resolution palaeodemographic data from regions across and beyond the greater Southwest, where archaeological radiocarbon data...

Explaining variation in human population density constitutes a basic research problem in human ecology and archaeological science. To contribute to this basic research problem, we build a graphic model and conduct a global analysis of the effects of ecological variables, controlling for technological differences, on human population density. Our re...

Questions regarding population stability among animals and plants are fundamental to population ecology, yet this has not been a topic studied by archeologists focusing on prehistoric human populations. This is an important knowledge gap. The fluctuation of human populations over decades to centuries – population instability – may constrain the exp...

Questions regarding population stability among animals and plants are fundamental to population ecology, yet this has not been a topic studied by archaeologists focusing on prehistoric human populations. This is an important knowledge gap. The fluctuation of human populations over decades to centuries-population instability-may constrain the expans...

The northern American Southwest provides one of the most well-documented cases of human population growth and decline in the world. The geographic extent of this decline in North Amer- ica is unknown due to the lack of high-resolution palaeodemographic data from regions across and beyond the greater Southwest, where archaeological radiocarbon data...

I conduct the first comparative analysis of long term human population stability in North America. Questions regarding population stability among animals and plants are fundamental to population ecology, yet no anthropological research has addressed human population stability. This is an important knowledge gap, because a species’ population stabil...

I analyzed the relationship between subsistence strategy, long-term population stability, and climate stability by using radiocarbon dates as representative of relative population change in North America. I gathered almost 40,000 radiocarbon dates within the United States and Canada using the Canadian Archaeological Radiocarbon Database (CARD) and...

paleodemography, species richness, population density, stability

radiocarbon, paleodemography, boom-and-bust cycles