Hands on Nature: Animal disguises and frogs

Hands-On-NatureBy Caitlin Waddick

Animal Disguises and Surprises
In April, Hands on Nature (HON) classes at Shelburne Community School (SCS) focused on how animals hide in plain sight, mask their true identities or use coloration to send a message to others. Predator animals want to remain unnoticed as they get closer to their prey. Prey animals want to be hard to see so predators won’t eat them.

The HON activities included a puppet show, a slideshow, and several hide-and-go-seek-style activities to illustrate animal disguises and surprises. We learned specific terms for types of camouflage and adaptive coloration. Here are some examples:

Matching color is used by many birds and their eggs, such that both the birds and their eggs match the color patterns of their surroundings. Many animals, such as the snowshoe hare, the short-tailed weasel, and the white-tailed deer, have coats that change color to match the color patterns of the season.

While a mother deer is away feeding, a fawn’s coat of white markings hides it among the patterns of light rays along the forest floor. This pattern exemplifies disruptive coloration because the outline of the animal’s body is not easy to discern from its surroundings.

Countershading is my favorite term because it plays with light and shadow. For example, a frog viewed from below has a light-colored belly, helping it to disappear in the brightness of the light. Viewed from above and looking down, the same frog has dark green and brown skin that conceals it among muddy water. Many birds also have countershading.

My kids’ favorite way that animals conceal themselves is called masking, and the spittlebug may be their favorite animal that masks itself by hiding in a protective covering. The spittlebug hides itself in bubbles that it makes from the plants’ sap. The bubbles are distasteful to predators and keep the spittlebug cool in summer.

Mimicry occurs when an animal tries to look like something it is not. For example, giant swallowtail butterflies, when they are caterpillars, resemble bird droppings. You can view a picture at the website associated with the book “Naturally Curious” by Mary Holland.

Other caterpillars and insects mimic bark, leaves, buds, flowers, fruits, and tendrils to avoid detection by hungry birds in spring who seek food for their offspring.

Bright, warning colors can communicate to others that an animal is poisonous; bad-tasting; foul-smelling; or able to sting, bite, or irritate. Monarch butterflies, which are bright orange and black, taste bad and birds easily recognize and avoid them. Bright yellow and black bumblebees enjoy relative safety due to their warning colors too.

Flash coloration is often a secondary method of defense. If an animal is seen in spite of its attempt to conceal itself, it may have markings it can use to startle or confuse a predator, in the same way as an unexpected flash of light near your face might startle you.

If I were a small bird after an io moth for my dinner, I might confuse its big black spots for the eyes of an owl, perhaps after me!

The Amphibians: Frogs, Toads, and Salamanders
In May, Hands-On Nature classes are listening to the sounds of frogs. Male frogs may have deep croaking voices or chirp in high notes. They are probably trying to call for mate or relay a warning of danger. They might be trying to proclaim “Rain!” or “This is my lily pad!” The frogs that sound like ducks are recently-thawed wood frogs.

Several HON activities demonstrate how amphibians change shape in the process of metamorphosis from larvae to adult. They differentiate several stages in their life cycles.

A young frog or toad is a called a tadpole or polliwog, and it has a tail and gills, which disappear as it becomes an adult. Most salamanders follow the same pattern.

In Vermont, the Eastern Newt is an exception. As a green larva with gills, it loves mud, and you will probably never see it. As a juvenile, we call it a red eft, which has absorbed its gills and grown lungs. Also, its digestive tract changes from one of an herbivore to one of a carnivore. Its brilliant orange-red skin, which secretes toxins, makes it easy to find in forested areas of Shelburne. You are most likely to see them after a rainstorm because the moisture allows them to travel.

After two or three years on land, the red eft usually changes into the olive-green Eastern Newt, which lives in water. However, some populations of Eastern Newts never loose their gills but bypass the eft-stage to live in water all their lives, and others become Red Efts who return to water only to breed.

For identifying frogs, toads, and salamanders, we are teaching their field markings, which are shapes and color patterns that distinguish species. A distinctive feature among frogs is a set of raised ridges running alongside some frogs’ backs. These dorso-lateral ridges are found in green frogs, but not in bull frogs.

You can enjoy the symphony of spring by listening for the courtship calls of frogs and toads. Frog eggs are usually clumped, while toad eggs are laid in a string arrangement. Salamander eggs are larger than frog eggs, but there are fewer in a clump. You can use a net and bucket to capture and release a few eggs or tadpoles for short-term observation. As always, be careful of your surroundings so you do not disturb wildlife, and follow the law by leaving wild animals in the wild.

Hands-On Nature 2013-4
The Hands-On Nature program at Shelburne Community School (SCS) is concluding another successful year. We taught and learned about insects (September), leaves (October), cones and conifers (November), snow (January), animal tracks (February), bird nests (March), animal disguises (April), and frogs and amphibians (May).

I am one of many volunteers who served multiple years, team teaching with other parents in various classrooms. My youngest child will not have HON next year as a fourth grader, and I would like to thank all the students and teachers, volunteers and organizers. I have had a great experience.

The PTO sponsors this program through third grade and pays for it through your donations and fundraisers, such as the box tops that you submit from General Mills products. Please submit box tops to collections sites at Shelburne Supermarket and the SCS main office. We get our curricula and related support from the Four Winds Institute in Vermont. Thank you for making HON possible.