2nd Grade Life Cycles
Life Cycles and Plant Communities
Half-day trip
(Morning trip: 9:30-11:30; Afternoon trip: 12:20-2:00)
Observe plant and animal growth, reproduction, habitat, survival needs, and changes in plant communities.
Unit – “Life Cycles” (Fall or Spring)
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Students begine learning as soon as they board the bus! Naturalists discuss various stages of the life cycles of animals, plants and insects. Basic needs required to complete a life cycle are reviewed. Organisms that lay eggs are compared to those that have live births. Phases of growth are considered, and students are asked "does a car have a life cycle?" Learning to OBSERVE and make a "best guess" or SCIENTIFIC HYPOTHESIS of what is happening in the field is an important aspect of this trip.
Plant life cycles - habitat resources, pollination, fruiting bodies, and seed dispersal are observed. When possible, tree rings showing growth conditions and tree age are examined.
Fungi life cycles - fungi propagation is discussed, as is the interesting role fungi play in breaking down dead and decaying organic matter.
Animal life cycles - various life spans, birthing scenarios, adult behaviors, and death are observed.
Insect life cycles - larvae undergo complete metamorphosis, whereas nymphs undergo incomplete metamorphosis. Students look for caterpillars (larvae) of various butterflies and moths (see the monarch life cycle). Examples of nymphs can be found in milkweed bugs. A nymph grows larger, but with each phase it retains many of the characteristics it will have as an adult. Another nymph example can be found in the dragon fly life cycle, below:
The interdependence of plant, animal and insect life cycles is discussed. A great example is the monarch butterfly and the milkweed plant. Click HERE to learn more about monarchs.
Other insects depend on the milkweed plant. Unlike the monarch butterfly, the milkweed bug larvae does not undergo complete metamorphosis. It grows to adulthood through a series of nymph phases. Students may see multiple phases of milkweed bug, all on the same plant.
Parenting styles come in many forms. A turtle lays an egg, and leaves the nest - the babies will know just what to do when they hatch. In comparison, a human will parent a child for decades, helping to guide them well into adult hood. Many animals use special strategies to keep their babies safe, and some people mistakenly think the babies have been abandoned. A cottontail rabbit does not stay with her babies, except to feed them, because she does not want to attract predators to her nest. If you come across a rabbit nest, chances are the mother is close by and watching. Leave the babies in the nest. If you find them pulled from the nest, you can tuck them back in to the hole and cover it with leaves. The mother may move the babies later that night, but she will not reject her babies just because you touched them. Click HERE to watch a wild rabbit feeding her young.
Proper Trail Etiquette Protects Students and Wildlife
Naturalist guides are positioned at the front of students groups. A calm walking pace and quiet voices mean increased opportunities to observe and learn about plants and animals in the area.
Michigan is home to a wide array of wildlife, including the eastern massasauga rattlesnake. This small, shy snake is Michigan’s only venomous snake. It is a protected species that is increasingly rare due to habitat loss. Massasauga means “great river mouth” in Chippewa, a nod to this snake’s preference for marshes and wetlands where its favorite foods - frogs and small rodents – can be found. The massasauga is a member of the pit viper family (Viperidae), considered to be the most highly developed of all the snakes. Pit vipers are named for the heat-sensitive “pits” located behind their nostrils. Curved fangs retract when not in use. When compared to other rattlesnakes found in the United States, the massasauga is the smallest and has the least toxic venom. Nonetheless, any bite from a massasauga should receive prompt professional medical attention.
Female massasaugas mature at three years. Massasauga rattlers are ovoviviparous (unshelled eggs develop in the body of the parent and hatch within or immediately after being expelled). Young are born in litters of 2 – 19.
Once out of hibernation in spring, massasaugas may “sun” or warm themselves during the day, but are generally nocturnal. On the trails, approaching footsteps alert the snake to arriving humans, giving the snake time to retreat to safety. Students should stay behind the naturalist guide on field trips. If a group encounters a massasauga, their guide will facilitate viewing from a distance and discussion of the snake’s special adaptations.
Learn more about massasaugas at:
State of Michigan Department of Natural Resources
Michigan Society of Herpetologists
Learn more about Michigan Snakes at: