Wildlife Migrations - Energetic Causes and Consequences

Abstract

Many species embark upon regular, long-distance journeys that are referred to as migrations. This lesson will cover the biological and ecological drivers of wildlife migrations and the role migratory species play in transferring energy and nutrients between disparate ecosystems. The lesson begins with the students collecting data on humpback whale movements. They will identify individual whales based on pictures of whales’ tails (flukes) and record where/when the whales were (re)sighted. They will be asked to identify patterns among their observations and draw conclusions about whether or not humpback whales are a migratory species. This will set the stage for a general discussion about migration. Then, working in groups, the students will learn about five different migratory species and they will measure out the distance of these species’ migrations using paperclips. This will provide a foundation for discussing how and where migratory animals transfer energy. Finally, the students will work in groups to research a migratory animal in their state and they will draw a map of the species’ migratory route. Through this lesson, students will learn about seasonal variation in natural resources, behavioral cycles of organisms, predator/prey interactions, and conservation of energy. While doing so, they will develop their observation and reasoning skills, and will engage in mathematics and geography. Wildlife Migrations - Energetic Causes and Consequences (120 minutes)

Learning Objectives  Differentiate between migration and other types of movement.  Understand the drivers of wildlife migration, including seasonal variation in environmental conditions and resources as well as biological cycles of organisms.  Understand the concept of conservation of energy and the role of energy in wildlife migrations, including energetic causes and consequences of migrations.  Understand the role of migratory species in transferring energy between disparate systems and the importance of predator/prey interactions.  Develop observation and reasoning skills.  Practice making simple mathematical calculations.  Gain experience drawing maps.

Grade 6 standards: Strand 1: Inquiry Process > Concept 2: Scientific Testing (Investigating and Modeling)  PO 5. Keep a record of observations, notes, sketches, questions, and ideas using tools such as written and/or computer logs. Strand 1: Inquiry Process > Concept 3: Analysis and Conclusions  PO 1. Analyze data obtained in a scientific investigation to identify trends.  PO 2. Form a logical argument about a correlation between variables or sequence of events (e.g., construct a cause-and-effect chain that explains a sequence of events). Strand 2: History and Nature of Science > Concept 2: Nature of Scientific Knowledge  PO 3. Apply the following scientific processes to other problem solving or decision making situations: observing, organizing data, inferring, comparing, measuring Strand 4: Life Science > Concept 3: Populations of Organisms in an Ecosystem  PO 1. Explain that sunlight is the major source of energy for most ecosystems.  PO 2. Describe how the following environmental conditions affect the quality of life: climate.

Grade 7 standards: Strand 1: Inquiry Process > Concept 2: Scientific Testing (Investigating and Modeling)  PO 5. Keep a record of observations, notes, sketches, questions, and ideas using tools such as written and/or computer logs. Strand 1: Inquiry Process > Concept 3: Analysis and Conclusions  PO 1. Analyze data obtained in a scientific investigation to identify trends.  PO 2. Form a logical argument about a correlation between variables or sequence of events (e.g., construct a cause-and-effect chain that explains a sequence of events).  PO 5. Formulate a conclusion based on data analysis. Strand 2: History and Nature of Science > Concept 2: Nature of Scientific Knowledge  PO 3. Apply the following scientific processes to other problem solving or decision making situations: observing, organizing data, inferring, comparing, measuring Strand 4: Life Science > Concept 3: Populations of Organisms in an Ecosystem  PO 2. Explain how organisms obtain and use resources to develop and thrive in: niches, predator/prey relationships  PO 3. Analyze interactions of living organisms with their ecosystems (limiting factors).  PO 4. Predict how environmental factors affect survival rates in living organisms. Grade 8 standards: Strand 1: Inquiry Process > Concept 2: Scientific Testing (Investigating and Modeling)  PO 5. Keep a record of observations, notes, sketches, questions, and ideas using tools such as written and/or computer logs. Strand 1: Inquiry Process > Concept 3: Analysis and Conclusions  PO 1. Analyze data obtained in a scientific investigation to identify trends.  PO 2. Form a logical argument about a correlation between variables or sequence of events (e.g., construct a cause-and-effect chain that explains a sequence of events). Strand 2: History and Nature of Science > Concept 2: Nature of Scientific Knowledge  PO 1. Apply the following scientific processes to other problem solving or decision making situations: observing, organizing data, inferring, comparing, measuring Strand 4: Life Science > Concept 4: Diversity, Adaptation, and Behavior  PO 1. Explain how an organism’s behavior allows it to survive in an environment.  PO 5. Analyze the following behavioral cycles of organisms: migration.

Materials (for 24 students) 24 Humpback whale photo ID lists** 9 Poster boards with humpback whale photos** 24 Animal information sheets (provided below) 24 Novel Migration Worksheets (provided below): salmon (3), monarch butterfly (3), humpback whale (4), leatherback sea turtle (6), Arctic tern (8) 24 Research notebooks 5 Computers with Internet access 690 Large paperclips Markers, crayons and/or colored pencils Large paper **Print from one of the websites suggested below. During 1. Pass out the humpback whale photo ID lists and have the students look at snack them as they eat. (Suggestion: For the ID lists, only print pictures of the whales that are used on the poster boards in the Engage activity.) 2. Ask what they see? 3. Help them recognize: a. They are looking at pictures of whales’ tails (called a fluke). b. Each fluke is different: some have more black/white, some have unique markings, etc. 4. Explain that these are pictures of real whales collected by people all over the world. Humpback whale flukes contain a unique pattern of black and white that is as individually unique as our fingerprints. Scientists take pictures of each fluke they see and use this data to track individual animals. Has the whale has been spotted before? If so, when was it last seen? Where? How many times has it been seen/how old might it be? If it’s a female, has it been spotted with a calf (baby)/did it reproduce? a. Photo identification is a great research tool because you do not have to disturb the animal by capturing it and tagging it with a unique identification number, and you can identify animals from a distance. Engage 20 minutes: 30 minutes 1. Scenario: The students are researchers trying to figure out the movement patterns of humpback whales. They need to know which areas of the ocean are most important for this endangered species, so they can help policy makers establish marine protected areas (i.e., Where are the whales found most often and does this vary over the course of the year?). They will need to make observations about whale sightings and try to draw conclusions about the movement patterns of humpbacks across the Pacific Ocean. 2. There will be 3 stations around the room (or outside on the playground). Each station represents a different region of the world - 2 tropical (Costa Rica and Hawaii) and 1 temperate (Alaska). 3. At each station, there will be a poster board with pictures of whales’ flukes displayed. You can find pictures of whale flukes at: http://www.splashcatalog.org/ OR http://www.afsc.noaa.gov/ABL/Humpback/pdf/HW_Printable_Catalog_v 1.pdf a. Round 1 (5 minutes) will simulate the first summer. The students will have to go around to the poster boards at each station and record which whales are there in their lab notebook using the whale photo ID list. If they don’t feel like they were able to identify all of the whales at each station in the time provided, tell them not to worry. They will get a chance to share their data with their classmates at the end of the activity. Researchers often collaborate and share data with one another. i. Begin with 1 whale in Alaska, 4 whales in Hawaii and 4 whales in Costa Rica. For example (the letters represent different individuals):  Hawaii: A, B, C, D  Costa Rica: E, F, G, H  Alaska: I b. Round 2 (5 minutes) will simulate winter. The teacher will put up the next three poster boards with fluke photos at each station. The students will go around to all of the stations again and make observations about which whales are there. They record their observations in their lab notebook. i. For this round, 3 of the whales from Hawaii and 3 of the whales from Costa Rica in round 1will join the 1 whale from Alaska in round 1 in Alaska for round 2, 1 whale from Hawaii in round 1 remains in Hawaii, and replace 1 whale from Costa Rica in round 1 with a new whale in Alaska (total of 8 whales in Alaska and 1 in Hawaii). For example (the letters represent different individuals):  Hawaii: A  Costa Rica: -  Alaska: I, B, C, D, E, F, G, J c. Round 3 (5 minutes) will simulate the second summer. The teacher will put the final three poster boards up at each station. The students will go around to all of the stations again and make observations about which whales are there. They record their observations in their lab notebook. i. For this round, 0 whales will be in Alaska, the 1 whale that was in Hawaii for rounds 1 and 2 will remain in Hawaii, 3 of the whales from Hawaii in round 1 and Alaska in round 2 will be back in Hawaii, 1 whale from Costa Rica in round 1 and Alaska in round 2 will be replaced by a new whale in Costa Rica, and the remaining 4 whales from Alaska in round 2 will return to Costa Rica (total of 4 whales in Hawaii and 5 whales in Costa Rica). For example (the letters represent different individuals):  Hawaii: A, B, C, D,  Costa Rica: H, I, F, G, J  Alaska: - d. Give the students 5 minutes to share and “analyze” their data, and discuss their results with their peers. 10 minutes: 1. Ask the students what they observed. a. Most humpback whales were observed in the warm/tropical areas (i.e., Costa Rica and Hawaii) in the winter and the cold/temperate area (i.e., Alaska) in the summer. b. Most individuals were seen at the same station both summers. c. Some whales were only seen once. This raises the question: Where did they go? What happened to them? Scientists face these same uncertainties. 2. Ask the students why they might have observed these patterns. Why are the humpbacks moving from place to place? Why are they in cold temperate waters in the summer and warm tropical waters in the winter? 3. Ask if they know what we call these kinds of regular, long distance movements? Migration 4. Provide background information on wildlife migrations using the following prompts: a. What is migration? b. Why do animals migrate? What biological or ecological factors cause an animal to migrate? c. What triggers these migrations? What is the biological or ecological cue? d. What is a season? What makes seasons differ from one another? e. What do you do in the fall, winter, spring, summer? Do you do different activities? Do you eat different things in different seasons? Why? f. What are the potential costs of migrations? Benefits? Explore 10 minutes: 30 minutes 1. Have students get into groups: a. Salmon (3 students) b. Monarch butterfly (3 students) c. Humpback whale (4 students) d. Leatherback turtle (6 students) e. Arctic tern (8 students)

2. Each group will be assigned a migratory animal and each student will be given an information sheet for that species that describes fun facts about the animal and its migration.

3. The groups will use paperclips to measure out the distance traveled by their animal. Each paperclip will be equivalent to 100 miles. a. Salmon – 1,000 miles round-trip (1,609 km) (10 paperclips) b. Monarch butterflies (4th generation) – 3,000 miles (4,828 km) (30 paperclips). c. Humpback whale – 9,000 miles round-trip (14,484 km) (90 paperclips) d. Leatherback turtle – 12,000 miles round-trip (19,312 km) (120 paperclips) e. Arctic tern – 44,000 mile round-trip (70,811 km) (440 paperclips)

 Give your students a frame of reference that will make sense to them (e.g., 100 miles is approximately the distance between Phoenix and Tucson, twice the length of Rhode Island, etc.)

 Encourage the groups to share the paperclip track building responsibility. This is especially important for the Arctic term group - each student will need to assemble ~55 paperclips to measure out the full 44,000 miles traveled by a single tern.

20 minutes: 1. Have each group present the information on their animal information sheet and the length of their paperclip track to the class.

Explain 10 minutes: 10 minutes 1. Introduce/review the following concepts: a. Nearly all of the chemical energy on Earth came from the sun, originally as solar energy. b. Seasonal variation in resources (e.g., day length, water, temperature, primary production, etc.) drives migrations. c. Migration is energetically expensive and risky, but the benefits outweigh the costs. d. Some animals have to store large amounts of energy to complete their migration (e.g., birds, humpback whales). e. Animals are adapted to reduce energetic loss during migrations (e.g., hydrodynamic body of humpback whale, Arctic terns gliding on prevailing winds). f. Energy is neither created nor destroyed – only transferred. g. Energy is critical to build tissues, hunt for prey, reproduce, etc. (metabolism). h. Energy is stored in the chemical bonds of biological tissues. It is transferred from prey to predators, from plants to herbivores, and it is broken down and released with decomposition. i. Energy is transferred between ecosystems via animal migration. 2. Engage the students in a conversation regarding how, when and where their migratory species from the “Explore” section transfers energy between ecosystems. a. Salmon: Salmon spend most of their life eating and growing in the ocean. When they are ready to reproduce, they migrate back to their natal stream. During their migration upstream, salmon are consumed by many predators, including eagles and bears, so the energy acquired by the salmon in the ocean becomes part of the terrestrial food web. After laying and fertilizing their eggs, many salmon species die. Their decomposing bodies nourish the upland streams where they were born. b. Monarch butterflies - Monarch butterflies eat milkweed in temperate latitudes. As the monarchs die, and subsequently decompose, in transit to winter hibernating grounds, they transfer the energy from northern milkweed plants to ecosystems distributed between Canada and Mexico. c. Humpback whales - Humpback whales filter feed tiny crustaceans, plankton, and small fish from cold northern surface waters of the ocean during the summer. Then, they travel back to warm tropical breeding grounds in the winter. When they give birth and shed the placenta, the energy stored in it, which was acquired while feeding in high latitudes, is transferred to the tropical ecosystem where it is a source of food for other marine species. Also, when whales die, they bodies provide food and habitat for benthic (ocean floor) communities thereby transferring the energy they gained from feeding along the ocean surface to communities in the deep sea. d. Leatherback turtles - The energy they obtain from jellyfish in northern waters is used to produce eggs. They migrate to tropical and subtropical beaches (that are nutrient-depleted) to lay their eggs. The eggs hatch and the remaining egg shells and yolk (built from the energy derived from jellyfish) stay behind and nourish the beaches. e. Arctic terns: Arctic terns forage on land and in the sea. Energy acquired in these ecosystems is transferred to other ecosystems as they themselves become prey to predators on land and in the sea.

Expand 25 minutes: 40 minutes 1. Have students get into groups and identify animals that migrate in or through their state. The Internet may be needed to research species. Remind the students that migrations aren’t always long geographic distances (e.g., they may be elevational). 2. Have the students identify the species as well as why, when, and where it migrates, and where energy is acquired and transferred along the way. 3. They should record their findings in their research notebooks. 15 minutes: 1. Have the groups draw a map of their animal’s migration that includes where energy is acquired and where it is released along the migration route.

Evaluate 10 minutes: 10 minutes 1. With the remaining time, have students make up their own migratory species and fill in the attached Novel Migration Worksheet that will help them describe their species’ journey, including when, why, and where their animal migrates, and where energy is acquired and transferred along the way. Novel Migration Worksheet

Name: ______Date: ______

Now, it’s your turn to create a species! Imagine that you just discovered a new migratory creature and explain its migration. Use the questions/directions below to guide you.

1. What is the name of your migratory species?

2. Draw a picture of your species in the box below.

3. Why does your species migrate? 4. When does its migration begin? When does its migration end?

5. Describe your species’ migration, including where it goes.

6. Where does your species acquire its energy? Where does your species transfer its energy to? How? Wildlife Migrations - Energetic Causes and Consequences

General Background Knowledge

Wildlife migration is large-scale regular (e.g., daily, seasonal, annual) movement of individuals from one place to another (Encyclopedia Britannica, National Geographic Education). Animals migrate primarily to find food/water or to reproduce. The trigger for the migration may be local climate, local availability of food or water, day length, or biological cycles (e.g., reproduction) (National Geographic Education). Migration is energetically expensive an can be dangerous, but the benefits outweigh the costs. Migration can describe four distinct, but related concepts (Dingle and Drake 2007): 1. persistent, straight, movement behavior; 2. relocation of an individual on a greater scale (both spatially and temporally) than its normal daily activities; 3. seasonal ‘to-and-fro’ movement of a population between two areas; and 4. movement leading to the redistribution of individuals within a population.

Migration can be either obligate, meaning individuals must always migrate, or facultative, meaning individuals can choose to migrate or not (Dingle and Drake 2007). Within a migratory species or a single population (i.e., group of individual animals of the same species located in the same geographic region), all individuals may not migrate (Dingle and Drake 2007). Complete migration is when all individuals migrate, partial migration is when some individuals migrate while others do not, and differential migration is when the difference between migratory and non-migratory individuals is based on age or sex, for example (Dingle and Drake 2007).

Many of the best known wildlife migrations occur on an annual cycle, but some organisms migrate daily. For example, many aquatic animals migrate vertically in the water column (diel vertical migration), sometimes travelling several hundred meters round trip (McLaren 1974). Some jellyfish migrate horizontally each day, traversing a few hundred meters (Hamner 1981).

Migratory Animals Background Knowledge

Leatherback turtle: Leatherback turtles are one of the world’s largest reptiles, growing up to 7 feet long and weighing up to two tons (National Geographic – Animals (a)). They are a pelagic (open ocean) species whose diet consists primarily of jellyfish and other gelatinous invertebrates (Fossette et al. 2010). Leatherback sea turtles travel across entire ocean basins to feast on jellyfish blooms. Northern latitude waters are more nutrient-rich than lower latitude waters, so there is more primary productivity. Increased phytoplankton biomass (i.e., very small plants that grow in the open ocean) leads to jellyfish blooms because phytoplankton are a key food source for jellyfish (Mills 2001). Leatherbacks migrate nearly 6,000 miles one-way to feast on these blooms (National Park Service (a)). Then, after feeding all winter, leatherbacks migrate back to tropical and subtropical beaches to lay their eggs. They need the warm beaches to incubate their eggs and the temperature of the nest actually determines the sex of sea turtle hatchlings (National Geographic – Animals (a)). By consuming jellyfish in nutrient-rich northern oceans and then migrating back to tropical and subtropical beaches to lay their eggs that were are produced with the energy derived from the jellyfish, the leatherbacks are transferring energy and nutrients between these two systems (Bjorndal and Jackson 2003). After the turtles hatch, the eggs biodegrade and provide essential nutrients to nutrient-poor low latitude beaches. This transfer of energy and nutrients helps sustain nutrient-poor beach ecosystems that are vital to many other plant and animal species (Hannan et al. 2007). Conservation note: During their long-distance migrations the turtles are threatened by a number of factors. In particular, leatherbacks cannot adequately differentiate between floating plastic bags and jellyfish, so they sometimes eat plastic bags and end up choking on them (Mrosovsky et al. 2009). Humpback whales: Humpback whales travel as much as 10,000 miles (16,093 km) round trip from cold temperate summer feeding grounds to warm tropical winter mating and birthing grounds (Folkens et al. 2002). During the winter, when the whales are in warm (sub-) tropical waters, adults do not eat, but live off their layer of blubber (fat); the young calves feed on their mother's rich milk (Folkens et al. 2002). Humpbacks migrate at 3-7 mph with almost no rest along the way (National Marine Sanctuary). During migrations, they cover over 1,000 miles per month. When they die, whales become entire ecosystems for benthic (ocean floor) communities. In this way they transfer energy from ocean surface waters to the deep sea. Monarch butterflies: Monarch butterflies depend on milkweed to lay their eggs and feed their larvae (US Forest Service, National Geographic-Animals (b)). These larval food plants grow in temperate parts of North America. Monarchs cannot withstand the freezing winter weather in the northern and central continental climates, so they migrate south to hibernate in Mexico and some parts of southern California for the winter (US Forest Service). In the spring, they migrate back north (US Forest Service). It takes four generations to complete the round-trip migration: the 1st three generations only live 2-5 weeks a piece, the fourth generation make the migration south and hibernates over winter (living up to 9 months) (US Forest Service). In the spring, after hibernating, they mate. The males die and the females begin the migration back north. Before the females die on the return journey, they lay their eggs. As the monarchs die in transit, they transfer the energy from northern milkweed plants to ecosystems distributed between Canada and Mexico. Salmon: Salmon are born in freshwater streams (Groot and Margolis 1991). They migrate to the open ocean where they spend most of their life eating and growing in nutrient-rich cold waters (Groot and Margolis 1991). When it is time to reproduce, they migrate back to their natal streams (Groot and Margolis 1991). How they find their way back to their natal stream is still unclear, but their sense of smell is believed to play a major role. Along the way, many salmon are captured and eaten by other predators. Some of the most notable predators that rely on salmon for their survival are bears and bald eagles. This food source helps bears “fatten up” for the winter, so they can hibernate in their dens without having to eat. After laying and fertilizing their eggs, the salmon die (Groot and Margolis 1991) and the energy contained in their tissues (derived from their time foraging in the ocean) is transferred to the upstream ecosystem. This transfer of energy “fertilizes” the base of the river food web. Arctic tern: The Arctic tern makes the longest annual migration in the animal kingdom (44,000 miles; 70,900 km) (Egevang et al. 2010). These seabirds spend their breeding season in the Arctic where the summer days are long between May and August. During the winter, November to February, they travel to the southern hemisphere (Antarctic) where the days are long between November and February (Egevang et al. 2010). Due to these incredibly long migrations, Arctic terns experience two summers (National Park Service (b)) and see more daylight than any living creature (including humans) on the entire planet! Along the way, they forage on foods they have obtained from multiple ecosystems, thus transferring energy between ecosystems up to 22,000 miles away! They conserve energy along the way by gliding on prevailing winds (Egevang et al. 2010). References

American Cetacean Society. "Humpback Whale Factsheet." Retrieved April 11, 2012 from http://acsonline.org/fact-sheets/humpback-whale/.

Bjorndal K.A., and J.B.C. Jackson. 2003. IU Roles of Sea Turtles in Marine Ecosystems: Reconstructing the Past. The Biology of Sea Turtles 2: 261.

Brower, L. P. 1995. Understanding and misunderstanding the migration of the monarch butterfly (Nymphalidae) in North America. Journal of the Lepidoptera Society 49.

Dingle, H., and V. A. Drake. 2007. What is migration? Bioscience 57:113-121.

Egevang, C., I. J. Stenhouse, R. A. Phillips, A. Petersen, J. W. Fox, and J. R. D. Silk. 2010 Tracking of Arctic terns Sterna paradisaea reveals longest animal migration. Proceedings of the National Academy of Sciences 107:2078-2081.

Folkens P.A., R.R. Reeves, and N.A. Society. 2002. Guide to marine mammals of the world. Alfred A. Knopf, New York.

Fossette, S., A. C. Gleiss, A. E. Myers, S. Garner, N. Liebsch, N. M. Whitney, G. C. Hays, R. P. Wilson, and M. E. Lutcavage. 2010. Behaviour and buoyancy regulation in the deepest-diving reptile: the leatherback turtle. Journal of Experimental Biology 213: 4074-4083.

Groot, C. and L. Margolis. 1991. Pacific salmon life histories, UBC press.

Hamner, W. M., and I. R. Hauri. 1981. Long-Distance Horizontal Migrations of Zooplankton (Scyphomedusae: Mastigias). Limnology and Oceanography 26:414- 423.

Hannan L.B., J.D. Roth, L.M. Ehrhart, and J.F. Weishampel. 2007. Dune vegetation fertilization by nesting sea turtles. Ecology 88: 1053-1058.

Hatch, Jeremy J. 2002. Arctic Tern (Sterna paradisaea), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/707

McLaren, I. A. 1974. Demographic Strategy of Vertical Migration by a Marine Copepod. The American Naturalist 108:91-102.

Mills, C. E. 2001. Jellyfish blooms: are populations increasing globally in response to changing ocean conditions? Hydrobiologia 451:55-68.

Mrosovsky N., G.D. Ryan, and M.C. James. 2009. Leatherback turtles: The menace of plastic. Marine Pollution Bulletin 58: 287-289. Murray, M. G. 1995. Specific nutrient requirements and migration of wildebeest. Serengeti II:231-256.

National Geographic-Animals (a). "Leatherback Sea Turtle (Dermochelys coriacea)." Retrieved April 11, 2012, from http://animals.nationalgeographic.com/animals/reptiles/leatherback-sea-turtle/.

National Geographic-Animals (b). "Monarch Butterfly (Danaus plexippus)." Retrieved April 11, 2012, from http://animals.nationalgeographic.com/animals/bugs/monarchbutterfly.html.

National Marine Sanctuary (Hawaiian Islands Humpback Whale National Marine Sanctuary). “Humpback Whale Facts.” Retrieved April 12, 2012, from http://hawaiihumpbackwhale.noaa.gov/documents/pdfs_info_facts/whale_fact_card.p df

National Park Service (a). 2010. "Leatherback Turtle (Dermochelys coriacea)." Retrieved April 12, 2012, from http://www.nature.nps.gov/biology/migratoryspecies/leatherbackturtle.cfm.

National Park Service (b). "Migration Basics." Retrieved April 12, 2012, from http://www.nps.gov/akso/parkwise/Students/ReferenceLibrary/general/MigrationBasi cs.htm

US Forest Service. "Monarch Butterfly Biology." Retrieved April 12, 2012, from http://www.fs.fed.us/wildflowers/pollinators/monarchbutterfly/biology/index.shtml.