A Journey Across Generations

• ○A. Monarchs remain near their birthplaces until changing weather forces them to leave.
• ○B. Monarchs complete their journeys by following older butterflies that already know the route.
• ○C. Monarch migration connects generations that play different roles in the annual cycle.
• ○D. Monarch migration depends mainly on the ability to remain active throughout winter.

The return south follows a different schedule.Several generations share the northward expansion, but a butterfly in the fall migratory generation can travel from its northern birthplace to the Mexican wintering grounds.Fall migrants can live much longer than summer adults.During migration, they stop to drink nectar from flowers, building and replacing energy reserves.

• ○A. Monarchs can meet their changing needs by remaining inside protected winter forests.
• ○B. Protecting monarch migration depends more on counting butterflies than on preserving plants.
• ○C. Monarchs use the same food sources throughout their development and seasonal travels.
• ○D. Supporting monarch migration requires different resources and habitats across the route.

A monarch’s needs also change during its life.Milkweed feeds the caterpillar, while flowering plants provide nectar for the adult.Because these resources serve different life stages, protecting winter forests alone cannot support the entire migration cycle.A field used for breeding and a patch of late-blooming flowers may serve different purposes, even though both lie far from the winter clusters.

• ○A. It contrasts the generations moving north with the generation making the fall journey.
• ○B. It replaces the description of reproduction with an explanation of winter shelter.
• ○C. It explains why northern milkweed is more useful than plants growing farther south.
• ○D. It shows that the butterflies moving north return south along a learned route.

• ○A. Caterpillars eat milkweed leaves; adult migrants stop to drink nectar from flowers.
• ○B. Scientists study monarch navigation; volunteers record sightings in different seasons.
• ○C. New adults continue north and reproduce; a fall migrant can reach Mexico from its northern birthplace.
• ○D. Monarchs cluster on winter trees; cool conditions help the butterflies conserve energy.

• ○A. It shows that winter forest damage is the main cause of milkweed loss farther north.
• ○B. It identifies losses in several habitats that the different conservation efforts address.
• ○C. It suggests that property boundaries keep monarchs from reaching suitable habitats.
• ○D. It compares the accuracy of volunteer counts with researchers’ navigation studies.

• ○A. Monarchs use the sun and an internal clock; researchers study how they locate wintering areas.
• ○B. Land-use changes can remove milkweed and nectar plants; people restore milkweed and grow nectar plants.
• ○C. Monarchs cluster on trees during winter; females lay their eggs on milkweed during spring.
• ○D. Fall migrants can live longer than summer adults; volunteers count monarchs in different places.

• ○A. Monarch migration involves several generations moving north and a fall generation traveling south. The cycle depends on varied habitats along the route, which conservation efforts work to protect.
• ○B. Monarchs make an impressive trip that deserves more attention. People should plant flowers and protect forests so future generations can enjoy watching these remarkable travelers.
• ○C. Monarch caterpillars eat milkweed, and adults drink nectar. People grow both kinds of plants, while researchers study how butterflies find their way to forests in Mexico.
• ○D. Monarchs spend winter clustered in Mexican forests, where cool weather conserves energy. Scientists study their navigation because the butterflies arrive without having visited the forests before.

• ○A. Monarchs have a difficult journey, and every property owner should create a protected feeding area.
• ○B. Monarchs travel mainly to find milkweed, and planted milkweed provides their food during winter.
• ○C. Monarchs are unusually clever travelers, and planting milkweed is the most valuable way to protect them.
• ○D. Monarchs migrate across generations, and restoring milkweed is one way people support their life cycle.