What is it Wednesday: January 5, 2022

Can you identify what's in this photo?

 

 

Each Wednesday morning 

on Camp Lutherlyn's Facebook page

 the Lutherlyn Environmental Education Program posts a photo. 

 

 

Readers have all morning and afternoon 

to make their best guess about what the photo is. 

 

Around 6 pm LEEP provides the answer and a brief explanation.

 

 

Each week's What is it Wednesday post 

will also be posted on the Nature of Lutherlyn blog, 

 after it is posted on Facebook,

sometimes with additional bonus information. 

 

In addition to bringing you current editions of What is it Wednesday 

on the Nature of Lutherlyn blog, 

we will be reposting old editions,

creating a What is it Wednesday archive. 

 

This photo was posted as a What is it Wednesday on

January 5, 2022. 

 

 

 

And the answer is....

These are tracks left behind by either slugs or land snails. 

What we are seeing is where they have traveled across the bench and eaten the thin layer of algae that is growing on the surface of the wood.

This explanation from “Tracks and Signs of Insects and Other Invertebrates,” by Charley Eiseman and Noah Charney, helps us understand how this track is made: “Like other mollusks, slugs and snails possess a radula, a straplike organ inside the mouth that is covered with many small, sharp teeth. As the animal slowly glides across the surface, it moves its head from side to side while scraping up algae with its radular teeth.”

The reason why the tracks look so “squiggly” is from the motion of the head side to side as the snail or slug travels along its path. With a closer look, you can make out tiny narrow lines within each track – these are the teeth marks. (It is hard to see them in this photo, and getting a closer view makes them blurry, but you may be able to see the little lines within each squiggle.)

The only difference between slugs and land snails is that snails have shells and slugs do not. Check out this previous What is it Wednesday to find out more about these fascinating little creatures:  https://lutherlynnature.blogspot.com/2020/06/what-is-it-wednesday-june-24-2020.html

Keep an eye out and maybe you will find tracks like these or other intricate signs that animals leave behind as they go about their lives!