7. Mission Migration
Take on an adventure countless animals do each season: a migration. Follow the tracks of a leatherback sea turtle, a monarch butterfly or a humpback whale in which we will see step by step how far those of the animal kingdom venture.
Get ready for a migration vacation!
Have you ever gone on vacation? What did you bring? Humans embark on migrations of their own frequently to go to a sunny destination or to visit loved ones; animals also embark on migrations of their own for a variety of reasons such as accessing food or finding more favorable weather conditions. Migrations is a movement of a group of animals from one location to another and back depending on changing seasons. Migratory animals that take part in these journeys are certain species of birds, mammals, reptiles, fish and insects. So, get ready to join the trip as we meet some animals that migrate in the water and in the air to learn about the ‘how’ , the ‘where’ and the ‘why’ of migrations.
Leatherback Sea Turtles:
Leatherback sea turtles are the biggest of the marine turtles who are divided into two groups of eastern and western populations. These turtles are the superstars of migrations as they journey crazy far at 10,000 miles at least each year while keeping an eye out for jellyfish as the western populations traverse the Pacific Ocean. Leatherback sea turtles travel from the coasts of Asia to the West Coast of the US to forage. Adult leatherback sea turtles can be sighted along the B.C coast during July and September. Also in the Pacific, they migrate to nest along tropical waters (such as Costa Rica, Malaysia and Indonesia) to lay their eggs. Once their eggs are tucked into the sands of the beach, the females return to the waves. These are great lengths sea turtles complete for jellyfish and for nesting which brings about the ‘how’ leatherback sea turtles do this trip. There’s the hypothesis that leatherback sea turtles orient themselves using the earth's geomagnetic field and the sun’s position on the horizon to navigate their migration. In short, they may use magnetic orientation and the measure of time of day to lead their way. This is a hypothesis that is still developing but it is massive trip regardless that leatherback sea turtles fearlessly embark upon.
There are many whales who migrate so they have better access to food and to breed; one of which is the legendary humpback whale. For instance when birthing and nursing calves, warmer shallow waters are preferred as baby whales are born without protective blubber, so migrating is instrumental in the survival of their little ones. Humpback whales live in wide range of waters and are known to migrate roughly 5000 km which wins them the award for the longest migration for any mammal on the planet. For example, southern humpback whale feed in Antarctica during the summer and thereafter migrate to Australia to breed and give birth. They can also be seen migrating along the West Coast slowly swimming in their pods from the chilly waters of Alaska to the warmer waters of Hawaii. The BC waters are particularly important to humpback whales for feeding during the summer months. The ‘how’ of humpback whales orienting themselves during migrations: it’s hypothesized that they use echolocation to tell each other where they are going and where they’re heading; in a way the map is being taught to the younger whales by the elders. Another hypothesis is that the humpback whales have magnetic material embedded in their brains that acts as a built in compass. Once more, our understanding of these trips are still understudy, but it’s no secret that it’s an incredible achievement.
http://www.dfo-mpo.gc.ca/species-especes/profiles-profils/humpbackwhaleNP-rorqualabossePN-eng.html https://www.wildaboutwhales.com.au/whale-facts/about-whales/whale-migration https://www.exploratorium.edu/theworld/sonar/navigation.html
So far we’ve covered water migrations now it’s time to cover some air with monarch butterfly migrations. They flutter an astonishing 5,000 km during the fall to the forests of Mexico for the winter through to spring all the way from southern Canada. To break it down by season the calendar of millions of monarch butterflies looks similar to the following:
They’re hanging out in southern Canada and are getting a bit too chilly for comfort and so they start journeying down through the States towards Mexico to warm up and enjoy the lovely weather.
They’re aware it’s going to get warmed up back north, so they start heading back up towards Canada. The female monarchs stop laying their eggs and leave behind the laid eggs to be hatched and for them to grow up through metamorphose into a beautiful butterfly and join in on the fun by heading north too.
Several (2-3) generations of monarchs are leaving Mexico to head to southern Canada and enjoy the pleasures of native flowers while sipping nectar.
And then the calendar repeats with each life cycle. The cue to leave is also the change of the seasons which also means the change of temperatures and food available. The ‘how’ of monarchs orienting themselves is not yet well understood. It is hypothesized that it’s mainly instincts guiding monarch butterflies while also having the changing seasons be the cues of when to follow those instincts. No matter how they make the trip, a million monarch butterflies flying from one end of North America to the other is a major mystery to me.
The Mission of Migrating:
As you can see from the migrations of leatherback sea turtles, humpback whales and monarch butterflies that these animals take on more than the average family vacation. They cross thousands of kilometres, allowing themselves to be guided by either instinct, elders, weather, magnetic pull or some other mysterious mechanism to get from point A to point B. It’s a natural phenomenon that is simply put: crazy. Could you complete the migration mission?
Questions for your Jr.Biologists:
- Are migrations dangerous for animals?: Absolutely! It is dangerous for these animals to travel to different locations that could have predators ready to catch a meal. For instance, the leatherback sea turtles cover such a great distance that they become particularly vulnerable to a wider range of predators over that distance. The term ‘survival of the fittest’ rings especially true in the case of these animals on the move who may not have areas of safety readily available.
- Do all animals learn where to migrate from their parents? How animals seem to just know where to migrate is still an ongoing study. However, we can have a solid understanding that not all animals learn the coordinates of the migration from their parents as they don’t get to meet their parents to have that discussion; such is the case for monarch butterflies and leatherback sea turtles who hatch from their eggs after their parents have left.
- Does climate change affect migrations? Yes, climate change has had a notable impact on migrating animals. These impacts are continuously being studied to explore questions about how rising temperatures alter migration patterns and how an influx of human activity establish impact the safety of where these animals lay their eggs.
Do you have any questions for Club Volunteers or our Coordinator, Leo? Ask away on our Discussion Board!
General Migration vids:
Leatherback Sea Turtles:
-Complete the Animal Migration Map here: https://www.neefusa.org/resour...
-Check out National Geographic’s animal tracker here: https://www.nationalgeographic.org/media/tracking-animal-migrations/
-Check the BC Cetacean Network for local animal sightings: http://wildwhales.org/
-Understand how animals navigate when migrating
-Acknowledge the threats that impact animal migrations
-Learn how differing species migrate
-Observe the great lengths migrating animals go and the mystery behind how they accomplish this feat.
Continue to 8. Fishing To Dishing »