Figure 1. Holocene midden sites (10,000 - 4,000 yrBP). Woodrats with
larger over all body size are generally more common at higher latitude.
Figure 2. Late Pleistocene midden sites (20,000 -
10,000 yrBP). Woodrats
from lower latitudes are much bigger during this time interval. Note the
individuals from Death Valley are very large, but also have a lot of variance
in their body size. It is likely that multiple species are present at this
site, and have not been sorted out yet.
Summary:
These maps show relative body sizes for Neotoma for the time slices “Holocene” and “Late Pleistocene”, respectively. A general pattern is for larger individuals to be found at lower latitudes during the ice age. This is consistent with estimates of Pleistocene climate which was cooler, and with much of North America being covered by an ice sheet.