Cycles in Nature
A butterfly emerges from its pupa case, drinks the sweet nectar of flowers, finds a mate, lays eggs and dies; the next generation will soon hatch to begin the cycle again. A tree stands bare of leaves as winter's snows fall, but the warmth of spring's sunlight finally encourages the buds to open. The cycles of living organisms reflect the seasonal cycles of their environment, and we find that these often overlap in a complex web - springtime brings warm rains, seeds sprout and leaves unfurl, insects emerge and eat young leaves, birds migrate northward to dine on emerging insects. These events repeat year after year in a cycle of ongoing change. Throughout this yearlong theme, students will examine the characteristics of organisms, paying particular attention to life and seasonal cycles.
Descriptions of Topics
Egg, nymph, larva, pupa! Different insects go through different stages as they grow from egg to adult. The process of metamorphosis and the timing of the changes play a big role in the success of this class of animals. We'll have a chance to observe a variety of different insects and look for examples of all stages of insect life.
Whenever you come home from a walk with burs on your socks or pop a jewelweed pod, you are playing a part in the dispersal of seeds. After a plant flowers and produces fertile seeds, those seeds must still find a spot to grow. We'll see what the inside of a seed looks like, how it holds all that is necessary for a new plant to grow, and explore outside to see the many different ways seeds move from place to place.
As winter approaches, we see different birds at our feeders and miss some of our favorite songsters in our woods. Some birds migrate hundreds of miles to find the food and shelter they need, but other birds stay right here through the cold months. We'll look at the challenges birds face if they leave for the winter and how they cope if they stay here.
Of the four seasons in the year, winter is most difficult for living things. Temperatures are often below freezing point of water, there is less light available, frequent snow cover, frozen ground, and a dearth of food for many creatures. Plants winter over in ways that ensure their ability to grow again in the spring. Each animal species also has a survival strategy, depending on its body type, food sources, and habitat.
One favorite sign of the changing seasons in New England is sap buckets hanging on maple trees. In the very early springtime when cold nights are followed by warm days, maple sap runs. To make maple syrup, we need to be able to identify a maple tree without its leaves. We'll study the buds and leaf scars; we'll look at the bark. If we find a maple, we can try tapping. It takes a lot of sap to make syrup, but, yum, it's worth the work!
You see these lumps and bumps on plants of many different varieties. What are they? A gall is an abnormal growth created on specific kinds of plants that is produced by some external stimulus. Insects can induce gall growth, and these galls provide food and shelter for the young insect. We'll compare a variety of galls and learn about their development. Imagine what it would be like to spend your life inside a plant stem! You'll be surprised how many galls you can find in your own schoolyard.
Winter trees may look dead, but they are very much alive; and, as spring approaches, we can see the signs of renewed growth. The buds start to expand, the leaves and flowers emerge, and though we can't see it happening, the tree is adding a new ring of wood to its branches and trunk. We can track the history of a tree's growth when we examine a tree slice, counting the rings and looking for differences in the rings that can tell us about the conditions of that year's growing season. See how many different kinds of winter trees you can identify in your own schoolyard. In the springtime, you can look again and match leaf to tree.
Cheerio cheery me, Cheerio cheerily. The wonderful sound of robins singing tells us all that springtime has arrived and the migrant birds have returned. Songbirds sing to attract mates and to establish and defend territories. It's fun to listen to the birds singing in the schoolyard and learn to identify some of the songsters in your neighborhood.
Flower to Fruit
Flowers come in all shapes and sizes, but they all serve the same function: to produce seeds. Flowers' design, smells, colors and blossom time all contribute to this purpose. We'll look at the inside of a flower to see how seeds develop and compare different kinds of flowers and their structures. Then we'll go outside to see what's blooming in our own backyard.
Their yellow heads brighten a green lawn, to the delight of many and the dismay of others. These hardy flowers have a host of adaptations that allow them to survive in the toughest of conditions. We'll look at the different stages of seed development by dissecting a dandelion head and then head outside to find plenty of examples of these flowers in all stages of development. Go ahead, blow those fluffy white seeds and see how far it travels in the wind.