TOPICS: Ecology and natural history of plants, birds, mammals, insects
LEVEL: Middle and high school
TIME: One period for field work, one period for lab work.
NOTE: This activity is a survey of the winter environment. Many of the topics introduced here are fully developed in other WSCP activities.
ADVANCE PREPARATION: You may wish to arrange additional adult supervision of students in the field. Check the weather forecast to choose a suitable day for the field work. Advise students to dress properly for the outdoors. Warm boots, hat, and gloves/mittens are essential
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MATERIALS:
Snow shovels can be shared among groups. Put blank masking tape labels on the plastic bags and collecting jars. For lab procedure, provide keys and reference books at the difficulty level most appropriate for your students. Golden Guides and Peterson Field Guides are good resources. Winter identification keys are available in other WSCP activities.
FIELD
:
A.
Possible observations include ventilation shafts and tracks made by small rodents, old goldfinch nests lines with thistle down in shrubs, springtails (snow fleas) on the snow
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B.
Students may see or hear birds in the open field but they must listen quietly. Groups of seed eaters such as tree sparrows and juncos may be seen in open fields
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C.
Goldenrod, aster, milkweed, dock are some of the winter weeds commonly found in open fields; grasses, plantain, dandelions may be found in lawns
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D.
It is reasonably safe to use a paring knife to open goldenrod galls held in a gloved hand, but you may prefer to have students collect the galls in the field and cut them open back in the lab
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E.
Students may find winter rosettes (ground-hugging evergreen leaves under the snow), storage roots or rhizomes of winter weeds. Active soil invertebrates (mites, insects, spiders, millipedes, centipedes) may be found on the soil surface or in deeper layers if the top layer is frozen.
FOREST
:
A.
Large and small mammal tracks may be seen. Students may find deer or rabbit gnawings
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B.
Common woodland birds seen in winter include chickadees, nuthatches, crows, cardinals, woodpeckers, blue jays
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C.
Common evergreen trees include hemlock, pine, spruce, fir.
FOREST (Continued
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D.
The plant life commonly seen on tree bark include algae (grass-green, microscopic, typically Protococcus), lichens (gray-green, crusty, algal-fungal association), and mosses (green, leafy). Beetles and other insects are commonly found under dead bark.
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E.
You may find mosses, evergreen ferns or herbs that remain green under the snow
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F.
Small invertebrates (mites, insects, millipedes) may be found in the soil.
POND OR STREAM
.
A.
Ponds typically freeze over, but not streams. Unless the pond is very shallow, it will probably not be frozen all the way to the bottom. Black ice (ice without air bubbles) is transparent to light. Even white ice (ice with air bubbles) and snow covered ice transmit some light, allowing photosynthesis to occur under the ice. However, deep snow reduces light transmission through the ice, and winter fish kill may result from oxygen depletion from decreased photosynthesis. This is especially true if the pond is polluted with organic wastes that require oxygen for decomposition
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C.
Birds seen or heard will depend on the surrounding habitat
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D.
Macroscopic plants in or near the water include mosses, algae, pond weed, grasses
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E.
Many insects overwinter in streams in the larval stage. You may find mayfly, beetle, caddis fly larvae. You may find snails, crayfish, small fish.
LAB PROCEDURE: Use the safe methods outlined in "What's inside Goldenrod Gall" to open galls. You may wish to have each group give a verbal description of their observations in class discussion.
QUESTIONS 5-7 require higher order thinking skills. We recommend that you discuss these questions in class before students write out their answers
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1.
Answers will vary. Animals and plants must obtain or conserve energy in order to survive in winter
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2.
Deciduous trees and shrubs are leafless and dormant but some plants remain green. These includes evergreen trees, ferns, herbs, mosses, lichens, and algae. The visible remnants of winter weeds are dead, but live tissue may be found at or beneath the soil as winter rosettes, storage roots and rhizomes; many still have seeds which contain dormant plant embryos
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3.
Live insects can be found in streams, in the soil, under the bark of trees, and inside goldenrod galls
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4.
Winter birds can be seen or heard in the woods or field. Some birds are migratory, but many birds are year-round residents. A few mammals hibernate (woodchuck, chipmunk) or semihibernate (raccoon, skunks); some migrate (certain bats), but most northern mammals are adapted for winter survival through morphological, physiological, and behavioral modifications. Evidence of active winter mammals include tracks, scats, burrows, and gnawings
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5.
Winter active animals may be herbivores and feed on plants (roots, stems, seeds). They may be carnivores and eat other animals.
They may be decomposers eating dead organic debris
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6.
Answers will vary depending on your study area. Woods typically have more signs of life in winter because woods have a larger zone of life (from below the soil to the top of the trees) than does an open field or aquatic habitat
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7.
In the spring you expect to see northward migration of some birds, nest building by birds, newborn mammals, adult insects newly emerged from the water, new plant growth including leaves, flowers, and so on
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8.
Answers will vary.