SNAILS of COLORADO
Snails
At first glance of the slimy odd looking critter, with their waving eyestalks most people say "gross." Wile they are indeed an aquired taste (not literally) they serve a really important role in native Colorado ecosystems. If you like native birds, reptiles, or plants then you should learn to like the snails as well.
Biology
Most land snails are hermaphrodites. This means that they have both the male and female reproductive organs. Some species can fertilize their own eggs but choose not to. The snails then lay their clutch of eggs in warm moist dirt. A couple weeks later baby snails hatch from the eggs. Some snails care for the eggs before they hatch but very few snails care for the young after hatching. Snail eat a wide range of things. There are carniverous, herbiverous, and detritivore snails. Carniverous snails have to eat equally slow prey such as other snails or insect larvae such as grubs. Detritivore snails eat the slightly decaying matter found on forest floors and are considered very important decomposers. Herbiverous snails eat plants. These are the snails that garderners have trouble with. Snails grow their own shells using calcium. The shell then protects all the important organs a snail has such as their heart and lungs. If a snail does not have enough calcium they can become sick (G. Barker, 2001).
Ecology
Snails serve several important functions in Colorado ecosystems. Most snail species carry bacteria that are beneficial to soils, such as nitrogen fixing bacteria, in a special pouch known as a crop. As they travel through the area they innoculate the soil with these bacteria making it better soil for plants to grow in. Since the snail needs calcium to build its shell, it is very good at absorbing metals, especially ones similar to Calcium metal. This has made the snail a useful tool in cleaning up metal polluted areas, restoring and making them safe for people, plants, and animals again. It also makes snails a key indicator species for soil health. The more snails you have the better your soil is. The presence of snails also adjusts the amount of Nitrogen and Phosphorous available to plants. This can directly influence plant species diversity and health (R. Dallinger, et. al., 2001). Many organisms use the snail as a calcium source. This is essential for egg laying organisms such as birds and reptiles. Many native animals rely on the snail, especially during breeding season (A. Allen, 2004).
Snails may be a key factor in reversing the native plant loss Colorado is experiencing. With Aspens becoming sick and beetles destroying trees, the snail could possibly help. Edward Karlin (1961) noted a significant correlation between healthy Aspen groves and the presence of land snails. No further study has been done since 1961 but Karlin suggests that there is a mutualistic relationship between the Aspen and the snails. The snails provide phosphorous for the trees and the trees are a source of calcium and algae. Since Aspen send out shoots and have a large connected root system there is an added bonus to the snails in a protected nesting site.
Health and Pest status
Recent media stories have included the current invasion of Giant African Snails in Florida. The media warned people against handling the snails due to a risk of contracting a parasite that could lead to meningitis, a dangerous swelling of the brain. However, there is little to no risk of contracting the parasite unless the snail is consumed raw. Rat lung worm can be found in land snails which in humans can lead to meningitis. It cannot be contracted by touch. It must enter the body through the digestive system. In fact it is so rare that only a few cases have been reported world wide over the past 3 decades and in all the cases it was due to eating raw or undercooked snails (A. Salleh, 2003). Gardeners have a special spot for snails as they can be extremely destructive to ornamentals and vegetables. On this website (the next tab above) there are some tips on how to deal with them humanely and with conservation in mind.
