#3 humans and dogs in the arctic · in dog sledding, a person—called a musher—drives a team of...
TRANSCRIPT
Tools of the Mind
#3 Humans and Dogs in the Arctic
Interdependence Series
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Interactive Read Alouds … Humans and Dogs in the Arctic by Tools of the Mind © 2019 Third Sector New England, Inc. on behalf of Tools of the Mind. All rights reserved. Published by Tools of the Mind Press Books may be purchased by contacting the publisher at: [email protected] Authors: Jillian Sullivan & Barb Wilder-Smith (Sarae Pacetta & Ruth Hensen co-developers original series) Editors: Erica Dusombre, Angela Robinson, Erin Tieuli, and Barb Wilder-Smith Thanks to Mandy McGuire and the Happy Hollow Park & Zoo for their knowledge and assistance Design: David Brooke & Jillian Sullivan First Edition
Dogs and humans have lived together for thousands of years. In return for feeding and caring for them, dogs serve as our loyal pets and friends. It’s not just about playing fetch together, though —the partnership between dogs and humans helped both species to survive, especially in the Arctic.
Do you have a dog or know someone with one? What are they like?
At the beginning of the last Ice Age, dogs didn’t exist. Back then, survival was tough. It could be difficult to hunt or gather enough food. Humans weren’t the top predators in their ecosystem—they lived in fear of other fierce carnivores like saber-toothed cats and wolves.
A branch of one of these early predators’ families became today’s dogs. Can you guess which one—the wolf family or the saber-toothed cat family?
All of today’s dogs were once part of the wolf family. Like most mammals, Ice Age wolves struggled to find enough food and stay warm in their cold ecosystem.
Most wolves were too scared to come near groups of humans, but at some point, a few wolves discovered they could sneak up and quietly scavenge bones and meat from Ice Age human’s leftovers.
Just like people, some wolves are fearful while others are more brave. Only the bravest wolves dared to come near humans and scavenge meat. Since the brave wolves got to eat more food than the frightened wolves, they were also more likely to survive.
Brave wolves in the Ice Age enjoyed an interdependent relationship with humans called commensalism. Commensalism means that only one of the two species benefits. The brave wolves got to scavenge from the early human’s trash. But while the wolves didn’t harm the humans, they didn’t help them, either.
Commensalism
A similar example of commensalism in today’s Arctic tundra is the relationship between the Arctic fox and the polar bear. The fox follows the polar bear around, scavenging from its leftovers. Since the polar bear wasn’t planning on eating those anyway, the fox’s actions don’t bother it, but the bear doesn’t gain anything in return, either.
Commensalism
The friendly, brave wolves were cared for by their human friends better than the unfriendly wolves. This meant they were more likely to survive and have babies who were also friendly and brave. These friendly, brave children were well-adapted to living with humans —the first tame dogs.
Some brave Ice Age wolf scavengers were friendlier than others and began to form a friendship with the humans they followed around.
As time went on, humans and their tame dog friends began to form a more mutualistic relationship. Mutualism means that both species help each other survive.
Mutualism
One way tame dogs began to help humans was in hunting. By combining human tools with the dogs�speed and tracking abilities, hunts were more successful and both species were able to eat better.
Early dogs also protected their human companions. They used their extra-sensitive ears to listen for danger, and then defended humans from wild animal attacks. Humans could worry less about predators when they had strong dogs guarding them!
Over time, dogs developed adaptive features that helped them survive alongside their human companions. Dogs who migrated with their humans to warm climates developed shorter fur and bigger ears to help keep them cool. Dogs in cold climates grew thicker fur and smaller ears to stay warm.
Which one of these dogs do you think is better suited to the cold? Why?
One of the most important roles dogs have played in human survival is in the Arctic. Scientists say that humans couldn’t have survived in these harsh climates without the help of their dog companions.
As early as 4000 years ago, one way dogs helped people living in Arctic regions was by pulling sleds.
Teams of sled dogs can easily pull heavy loads across the slippery snow, something that would take humans much more time and energy if they did it alone. Humans living in the Arctic could hunt better because they could travel farther to find animals and carry back large amounts of meat on their sled.
In dog sledding, a person—called a musher—drives a team of dogs who pull a lightweight sled. The musher calls “mush!” to tell the dogs to start running. Dog teams have to work together to pull the sled. A dog running too fast or too slow will throw off the whole team’s coordination.
musher
Sleds are long so they can carry loads
—or passengers!
rope harnesses
The strongest dogs go closest to the sled
to help steer.
These dogs provide most of the running
power. Lead dogs follow the musher’s
instructions and set the speed
for the whole team.
cargo
basket sled
wheel dogs
team dogs lead dogs
There are many breeds of sled dogs, but here is a common one—the Siberian Husky.
Over time, sled dogs have adapted to pulling sleds. They have long, thick coats to keep them warm, strong muscles for running long distances, and a sleek, lightweight body that helps them pick up speed.
Today, sled dogs are still an important part of Arctic life. They go on search and rescue missions to save people trapped in the snow or mountains. The first successful expedition to the South Pole used a sled dog team!
Imagine you’re the one driving this sled, travelling on an all-day trek to another town. What do you think would it be like? What kind of clothing might you need?
There�s a Junior Iditarod competition, too, where kids lead their own dog sled teams!
A famous sporting event in Alaska is the Iditarod. This is a long race between sled dog teams and their mushers, travelling almost 1000 miles across the snowy wilderness.
Dogs provide one other major benefit to their human companions—can you guess what it is?
Dogs provide friendship! Brave, friendly, and loyal dogs have been our best friends for a long time. Across history, dogs have been an important part of peoples’ lives, and we’ve been an important part of their lives, too. It’s one of the most impressive mutualistic partnerships in the animal kingdom.
Name one way dogs helped humans survive. How about one way humans helped dogs survive?
Glossary
Ice Age
wolf
dog
sled Arctic fox friendship
sled dogs
iditarod
Siberian husky