This website illustrates what we can learn from faunal remains from archaeological sites. It demonstrates the value of animal remains for answering questions about environments, human use of animals, and broader cultural issues during the Archaic Period (10,500-2,500 radiocarbon years before the present) in the interior part of eastern North America. It is based on research funded by a grant from the National Science Foundation (BCS-1430754).

We primarily use examples from two important Illinois archaeological sites that were studied as a part of this grant.  These sites are the Koster site, located in the lower Illinois River valley in Greene County, and Modoc Rock Shelter, located in the middle Mississippi River valley in Randolph County (see map). Both sites have occupations that span the Archaic Period of American Indian history. To learn more about the Archaic Period, please visit the Illinois State Museum web module on the Archaic Period in the MuseumLink Native American website https://www.museum.state.il.us/muslink/nat_amer/pre/htmls/archaic.html

Our research for this grant demonstrates the importance of preserving information about faunal remains in electronic databases and sharing these databases with other researchers. For more information on this research project and our research team, please visit the About section.

Human Activities

The animal remains excavated at most archaeological sites, including the Koster site and Modoc Rock Shelter, are primarily from animals that were hunted or collected by people. Ancient hunters, trappers, and fisherman brought animals back to their camps for food, raw materials, and other purposes. They may have eaten some of the animals or left parts of animals at the location where they were killed or collected.

At many archaeological sites, most of the bones and shells at camps are leftovers from meals. People at camps often broke bones into smaller pieces during butchering and food preparation. They may have cut up the carcasses of larger animals such as white-tailed deer (Odocoileus virginianus) and shared parts with other families at the camp. They may have steamed, boiled, or roasted parts of animals.  Even though meat surrounded the bones, cooking may have stained and weakened them.  

Bones and shells do not just represent food refuse. People made some bones and shells into tools and cared for them so they could be reused.  Some of these items may have been used in special ceremonies and buried in special contexts.  Furs, skins, feathers, bones, and shells were made into clothing and ornaments, but only the durable parts such as bone and shell normally survived. 

Many cultural practices incorporated animals. They were not just sources of food and raw material. People had special relationships with some animals, and some may have been important to their beliefs and religious practices. Some animals such as dogs or parts of animals made into objects, such as fans made from bird wings, were sometimes intentionally buried. Such special contexts suggest special relationships. Intentional burial of animals and artifacts made from animal remains also made them less subject to destruction. 

Natural agents also leave marks on and destroy bones. Domestic dogs living with the people at Archaic Period camps sometimes chewed or ate bones, especially those from food refuse. Domestic dogs were present during the Archaic Period occupations at both Koster and Modoc Rock Shelter, and we find animal bones that have been chewed by carnivores—likely the dogs.  Rodents sometimes gnawed bones and antler. We find rodent bones and rodent-gnawed bones in the Archaic camps at Koster and Modoc. The proportions of carnivore and rodent gnawed bones at Modoc and Koster are low. 

Camps at the Koster site and Modoc Rock Shelter were situated along the base of bluffs in locations where bones were rapidly buried. The sediments that eroded from the bluff tops and washed in from nearby creeks were non-acidic. Sediments built up rapidly at these sites and left layers of camp site remains with the oldest on the bottom and the youngest on the top. Bones at these sites are well preserved.

Some Archaic camps in Illinois were situated in areas where sediments were not being rapidly deposited, such as in the uplands. Bones were less likely to be preserved at these camps. Bones left on the ground surface were exposed to the natural elements ─ rain, snow, freezing and thawing, wind, and sun. These natural forces hastened the weathering and decay of animal remains. Some camps in Illinois occurred in areas with acidic soils such as pine forests or in areas that were alternately wet and dry such as low-lying floodplains. Bones were not well preserved in these conditions. Only the durable stone artifacts are preserved at sites in these areas.

At the Koster site, excavators individually plotted bones on maps and hand-collected them for some deposits. For other deposits at Koster, they dry screened sediments through 1/2" mesh. To collect small-scale remains, they saved bushel baskets of screened sediment from each excavation level for water flotation. They processed flotation samples in wash tubs fitted with a 1/16" mesh screen bottom. During flotation, sediments pass through the 1/16" mesh screen, and animal remains and other heavy remains collect on the screen. We call this processed sample the heavy fraction. For this type of flotation, archaeologists use a scoop fitted with 1/32" mesh to scoop out the light remains that float such as plant remains, small gastropod (snail) shells, and fish scales. We call this processed sample the light fraction.

During the 1950s excavations at Modoc Rock Shelter, the smallest mesh size used was 1/4".  During 1980 excavations at Modoc Rock Shelter, archaeologists collected standard-sized buckets of sediment from each excavation level for water flotation using 1/16" mesh, and as noted above also water-screened all other sediments through 1/16" mesh.  They used a flotation barrel for the flotation process. For this type of flotation, running water connected to the barrel washes the sediment to the barrel's bottom. Heavy, small-scale remains such as bones and freshwater mussel shells are collected in a 1/16" mesh screen in the barrel. Light remains that float (mostly plant remains, small gastropod shells, and fish scales) flow through a shoot and are collected in a 1/32" mesh screen. As noted above, the processed samples are called the heavy and light fractions. Archaeologists used the same flotation process for the 1984 and 1987 excavations at Modoc Rock Shelter. Use of flotation greatly improved the recovery of small bones and remains of bones from small-bodied animals including rodents and fish.

We sometimes refer to the remains collected on the large-mesh screens as macrofauna and the remains collected on fine-mesh screens as microfauna. How would the use of a large-mesh screen, such as a 1/2" mesh screen, affect the kinds of faunal remains recovered at the Koster site? Which screen mesh size do you think would recover the most bones from small-bodied fish and rodents? Research for our grant shows that there are strong differences between the kinds of animals represented in the samples processed through 1/4" or 1/2" mesh and 1/16" mesh at a site. If there are great differences in the kinds and body sizes of species recovered through large-mesh screening and flotation, then it is extremely important to study and present the results for both types of samples.  

Zooarchaeologists make decisions about what to analyze. They rarely analyze all of the faunal remains from a site because analysis of bones is time consuming.  When comparing animal remains from different camps at a site or among different sites, it is important to consider what was excavated at the site and how it was recovered. It is also important to consider how much and what kinds of samples were analyzed by the zooarchaeologist to see if the faunal assemblages from different occupations at a site or for different sites are comparable. 

Human Impacts on Animal Populations

Humans have impacts on animal populations. They kill animals for food and raw materials. Some people keep live animals.  For example, we know that Archaic Period people kept domestic dogs. Human use of animals has the potential to affect the sizes and distributions of wild animal populations. We can look for these impacts in the archaeological record. During the Archaic Period, Archaic Period people may have had local impacts on animal populations. For example, they intensely harvested fish from small floodbasin lakes in the lower Illinois River valley.  However, annual spring and fall floods of the Illinois River would have naturally restocked lakes.  

Human and Animal Responses to Climate and Environmental Change

Animal bones at archaeological sites provide evidence for climate and environmental changes. During the long Archaic Period, animal and human populations responded to climate changes, including rapid change at the end of the most recent Ice Age and a long period of warming and drying during the Holocene. We examine evidence for animal responses to the natural changes in climate, landforms, rivers, and plant and animal communities. We explore human responses to changes in the same natural features including the abundance and distribution of animals.

Scientists use the faunal data from archaeological sites to study long-term climate and environmental change. They use the past to model and predict how plants and animals will respond to future climate changes. The Neotoma Paleoecology Database includes data for plants and animals based on remains from paleontological and archaeological sites and natural settings such as lakes and bogs. It includes data from the original FAUNMAP database and North American Pollen Database that were developed at the Illinois State Museum and funded by the National Oceanic and Atmospheric Administration and the National Science Foundation.

Paleoecologists and climate modelers use data from Neotoma to study changes in the distribution of plants and animals over the last two million years.  Climate modelers have used these data to test their contemporary climate models that they use to predict future climate change and impacts. They use the contemporary climate model to "postdict" the conditions and plant and animal responses during past periods of known environmental change such as the end of the most recent Ice Age. They then test what the model yields for the past by comparing to what actually happened based on the Neotoma database.