A Dynamic Ecological Model for Human Settlement on California's Northern Channel Islands
Open Access
- Author:
- Jazwa, Christopher S
- Graduate Program:
- Anthropology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- March 06, 2015
- Committee Members:
- Douglas James Kennett, Dissertation Advisor/Co-Advisor
James William Wood, Committee Member
Lee Ann Newsom, Committee Member
Christopher J Duffy, Committee Member - Keywords:
- Archaeology
California
Channel Islands
Behavioral Ecology
Ideal Free Distribution
Complexity
Environmental Archaeology - Abstract:
- Settlement on California’s Northern Channel Islands can be described using two behavioral ecology models, the Ideal Free Distribution (IFD) and the Ideal Despotic Distribution (IDD). These models predict that (1) people will first establish permanent settlements in the regions ranked highest for environmental resources; (2) as population grows, people will settle progressively lower-ranked habitats; (3) resource depression should occur in the highest-ranked habitats prior to the occupation of lower-ranked habitats; and (4) under despotic conditions, residents of high-ranked habitats will force newcomers to less desirable locations to prevent resource depression. In this dissertation, I test these models using targeted survey, excavation, laboratory analysis, and radiocarbon dating of archaeological sites on Santa Rosa, the second largest of the Northern Channel Islands. On this island, the early permanent settlements (after ~8000 cal BP) were located in both high- and middle-ranked locations, with the most extensive settlement at the highest-ranked locations and only isolated sites elsewhere. Settlement at a low-ranked habitat is confined to the Late Holocene (after 3600 cal BP). Environmental change independent of human activities, including drought, influences the relative rank of different locations, adding a dynamic aspect to the model and potentially resulting in population movement. Furthermore, the despotic variant of the model (IDD) is prominent late in time as complexity and territoriality developed. This study expands on previous attempts to understand the environmental parameters for settlement on the Northern Channel Islands by modeling fresh water flow in the drainages on Santa Rosa Island. The hydrological model for Santa Rosa Island presented here incorporates geospatial and temporal data for climate (precipitation, solar radiation, wind speed, relative humidity, temperature), soils, vegetation, and topography to simulate the complex land-surface-groundwater behavior of island hydrology for hypothetical wet, dry, and median centuries. Drainages on the northwest and east coasts of the island have the largest runoff and are the most resilient to drought. This contributes to their high rank in the IFD/IDD models. This dissertation traces settlement patterns on Santa Rosa Island from the earliest available evidence for permanent settlement during the Middle Holocene (7550-3600 cal BP) through historic contact. The Middle Holocene was associated with increasing sedentism and an elaboration of diverse settlement and special purpose sites. A central place forager model describes the processing and transport costs of red abalone (Haliotis rufescens) and California mussel (Mytilus californianus), and how these costs influence archaeological assemblages at coastal and interior settlements. Permanent coastal sites were occupied year-round by larger populations and special purpose sites have faunal assemblages that reflect their distance from coastal shellfish beds. Starting around 1300 cal BP, there were important cultural changes associated with an increase in sociopolitical complexity. Permanent settlement condensed from a dispersed pattern to one that was nucleated at a small number of large coastal villages. The subsequent settlement pattern can be described using the IDD. Village residents prevented others from joining them, pushing the others to more marginal habitats than would be expected in the IFD. Fish was the primary food source at that time, so changes in the distribution of fish and other faunal species provide a useful tool to track these changes.