Tonight we continue with invertebrates—those spineless creatures without which no horror movie would be complete—and I am already expecting chills instead of thrills. Maybe to know them is to love them, so I’m going to give them a chance to win me over.
Keeper Margaret Rousser was back tonight to give us a proper introduction to the many-legged residents of our Bug House. Margaret supervises the invertebrate Keepers and is responsible for keeping the exhibits filled with interesting animals, so who best to promote this part of the Children’s Zoo?
All Insects are Invertebrates…
…but not all invertebrates are insects. In fact, 40% of invertebrates are animals like spiders, scorpions and centipedes. Margaret said that invertebrates are the most popular exhibits in zoos today. Does that surprise you?
We covered our scorpions and millipedes in the lecture on Arthropods, so tonight our focus is on insects, which are also Arthropods. They lay eggs, might have wings, and some can metamorphose from one shape to another, like frogs. Butterflies have all these traits.
Keeping Bugs in the Bug House
One of the challenges in keeping insects in a zoo is actually keeping them. Since all are pretty short-lived, constant replacements are needed and since they can fly and are small enough to get out through tiny openings, the exhibits have to be, well, bug-proof.
In our Bug House the walls have windowed cut-outs that show different naturalistic settings similar to the insects’ home turf. Behind the scenes, though, these little dioramas are more like aquarium tanks sitting on wheeled carts. When the insects are fed, or need other care, the tanks are wheeled backwards where they can be [very carefully] opened.
So….off we trotted with our flashlights to seek out the Bug House and its occupants. I can’t say I let myself look at the cockroaches very long, but the branch-like Walking Sticks were fascinating—especially their molted exoskeletons (their hard outer “skin” which looked exactly like them.
Our Honey Pot Ants use some of their colony members as food storage depots: the workers collect nectar and store it in the bellies of fat little repletes who hang from the ceiling of the nest all the time, taking food in and regurgitating it back up when needed to feed the others in times of food shortage. These ants are also predators: they kill and eat other insects like fruit flies.
And while we are on the subject of ants, there are the Leaf Cutter Ants. These are the most fascinating insects to watch as they literally turn trees and forest floors into moving green rivers. The “Forager” ants go off and cut leaves into pieces many times larger than they are, which they carry back to the nest. “Gardener” ants then grow fungus on the leaves which is later broken off and fed to the queen and others. Here’s a wonderful video showing it all in action: http://video.nationalgeographic.com/video/player/kids/animals-pets-kids/bugs-kids/leafcutter-ant-kids.html.
The Cobalt-Blue Tarantulas are absolutely gorgeous and absolutely venomous. These bugs are very aggressive and can live 20 years.
Chilean Rose Tarantulas, on the other hand, take a passive approach to defense: they have hairs on their bellies that are very irritating to predators who happen to get close enough.
Presentations are Next
We just got our final instructions for the presentations we each will be giving on Saturday. I’m going to talk about how our Black Tree Monitors, who only live in New Guinea (and zoos) teach us how the adaptations of animals and their environments are inseparable. That’s why we have to preserve rain forests and rivers and deserts and oceans: animals that are adapted to live one place can’t pick up and move somewhere else. And if their climate changes, their adaptations might not help them at all. Ask the polar the bears about this.
Wish me luck!