A teacher and mother of three who identified herself only as “Mom of Kearra” posted the following query to our website: “Why did the Calusa build these shell mounds?” Here is my answer.
The great mounds at Pineland, Big Mound Key, Mound Key, and other sites in southwest Florida are made up of shells, bones, ashes, charcoal, broken shell and bone tools, broken pottery, and dirt. In some cases, there are layers made up mostly of small whelks or conchs or oyster shells, with very little sand. These often contrast with dark-colored activity-surfaces or house floors with which they are inter-layered.
Some people think the layers of mostly shell mean that lots of shells were purposely brought in to the site to build the mounds up. But in every case in which we have done a detailed study of these so-called “fill” layers, we have found a mixture of shell, bone, charcoal, and quartz sand, that is, a midden. A “midden” is a garbage dump, basically. The fact that some of these layers are composed predominantly of a single species of shellfish (oyster, or lightning whelk, or crown conch, for example) is simply a matter of which particular shellfish were available at the time people were living there. In addition to fish—their main dietary staple—and a large variety of plant foods, they also ate shellfish such as oysters and conchs. In every case, there are good ecological reasons to expect an abundance of those species at particular times, and there is no reason to believe that the mollusk meats were not used for food. People used midden materials to build up their living sites higher, and sometimes they even heaped older midden materials up on top of mounds to make them higher. But what they used for such mound construction was simply food debris and other discarded materials, which is why we call these “midden-mounds.”
Now, to answer your question, we think they lived on top of these midden mounds, particularly after A.D. 1000. There are many advantages to being up high: catching a cool breeze on a hot day, escaping mosquitos and biting gnats, being safe from storm surges, and being able to see long distances so as not to be surprised by enemies approaching. Their villages were situated near food resources and fresh water. They accumulated massive midden-mounds—some more than 30 feet high—and they lived on top of them.
This article was taken from the Friends of the Randell Research Center Newsletter Vol 12, No. 2. June 2013.