Friday, September 22, 2006
Where have all the snails gone?
The above map I put together based on the summary paper by Jass (2004). In this paper, she echoes the call of Hubricht (1985) and others that much of the upper midwest is woefully undersurveyed for snail abundance. Notice the large number of Wisconsin counties with fewer than five land snail species reported for that county. The most populous counties (Dane, Milwaukee, Brown), those with state universities within them, have the highest abundance. This is definitely not a result of natural distribution - I've found snails in counties that have no official records. It likely reflects the fact that the researchers concentrated their efforts close to home. What does this mean? If we want to know the true extent of the distribution of snails on this continent, we need more people looking for snails. They are an excellent indicator species and have a great deal to tell us about the modern (and ancient) environment if we'd only stop to listen.