The Rainforest: Millipedes, snails and spiders

Invertebrates at night

Introduction

"Almost finished a new course on "life in the rainforest"! Here is a sample lesson on some nocturnal critters".

Many rainforest invertebrates are nocturnal and remain well hidden during the day. In this lesson, and the video above, we check the nightlife of some of the invertebrates associated with rainforest trees.

Many insects are nocturnal including a number of spiders.

Tree trunks in the rainforest provide a great habitat for invertebrates with their bark providing structure and sources of food including algae and bacteria which can be exploited by invertebrates.

If you select a few trees during the daytime and investigate the surface of their trunks you may not find any signs of life on the bark. If you return to the same tree at night, you may observe nocturnal species including millipedes and centipedes as well as snails and insects moving over the bark. If you look into the branches, you may also observe web weaving spiders setting their traps to capture moths and other nocturnal flying insects. This habit would also reduce their chance of being taken by a daytime insectivore including many species of birds.

A millipede emerges at night. Its nocturnal habit as well as its toxicity lowers the chance of ending up on the menu of a visual predators.

 A snail feeding on algae on the bark of a rainforest tree at night. The same snail wouldn't last very long if out and about during the day!

Being nocturnal may indeed be a good way of avoiding most of the visual predators including birds as well as other predators including lizards and skinks, which use vision to locate their prey. During the day, these same species adopt a cryptic habit, hidden in the nooks and crannies of the rainforest vegetation.