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1 .<-NARRATOR:->Listen to part of a lecture in a biology class.
1 .<-FEMALE PROFESSOR:->For today's discussion, we'll review the case study on how some animals have behaviorally adapted to their environments.
2 .Now you had to read about two animal species,:the Eastern marmot and the Olympic marmot.
3 .Marmots are rodents... they’re large ground squirrels about the size of an average house cat, and they live in a variety of habitats.
4 .And even though they spend the significant portion of the year hibernating, according to this case study, marmots are still considered excellent subjects for animal behavioral studies. Why is that?
1 .<-MALE STUDENT:->Well, when they’re not hibernating, you can find them in open areas, and they’re pretty active during the day, which makes them easy to observe, right? [rising tone]
1 .<-FEMALE PROFESSOR:->[encouraging tone] Unh huh. So, first let’s discuss the eastern marmots.
2 .They reside throughout the eastern region of North America where there’s a temperate climate, where the growing season lasts for at least five months of the year... which is when they do all their mating, playing, and eating.
1 .<-MALE STUDENT:->Oh, I see... at first, I wasn’t sure what ‘growing season’ meant just from the reading, but now I get it.
2 .It’s the amount of time it takes for them to grow, right? [rising tone]
3 .So it would be five months?
1 .<-FEMALE PROFESSOR:->Hm? Ohh, I’m sorry but no, It has nothing to do with that.
2 .It's not about the time it takes for Eastern marmots to grow,It's when the food is available.
3 .That is--when it’s not covered in snow and there’s no frost covering the grass, and um vegetative parts of uh, plants, herbs, and the flowers that marmots like to eat.
4 .So, ‘growing season’ refers to the availability of the food they eat. Ok?
5 .So now how would you describe the Eastern marmots' social habits?
1 .<-FEMALE STUDENT:->Well, they are really territorial, and loners, and just so aggressive even with other Eastern marmots.
2 .And their mating ritual is just so... impersonal.
1 .<-FEMALE PROFESSOR:->[agreement] Uh huh.
2 .Now when they emerge in the spring from hibernation, the mating process begins.
3 .For them, well, they come together to mate and then they go their separate ways.
4 .Then about six to eight weeks after birth, the offspring leave their mothers.
1 .<-FEMALE STUDENT:->Really? Just six weeks?
2 .Is it possible for the offspring to make it on their own so young? [concerned]
1 .<-FEMALE PROFESSOR:->Well, it's not as if they aren't ready for the real world because they are.
2 .Remember, they mature quickly and the weather's nice.
3 .Also they live in open fields where there is lots of edible vegetation.
4 .So roughly six weeks after birth, eastern marmots are just old enough to take their chances of surviving in a temperate environment. [pause]
5 .So how does this relate to their behavior?
1 .<-FEMALE STUDENT:->Oh, I get it.
2 .Since the climate's not too bad, the Eastern marmots don't have to rely on each other too much and they really don't need to stay together as a family to survive either.
1 .<-FEMALE PROFESSOR:->Uh huh. And in contrast... the Olympic marmots... what about them?
1 .<-FEMALE STUDENT:->Well, they live together as a family and take care of their young until they are at least two years old.
2 .They’re really friendly with each other, and what I really like is that they even have greeting ceremonies and they’re not at all aggressive and territorial like the eastern marmots.
3 .So their social behavior is so different from Eastern marmots because of the climate where they live?
4 .That seems so bizarre.
1 .<-FEMALE PROFESSOR:->Well, the Olympic marmots inhabit meadows high in the Olympic Mountains where the weather conditions are much harsher so there is a lot more wind and snow.
2 .The growing season only lasts about two to three months.
3 .So in that much shorter period of time, all the Olympic marmots, male and female, eat, play, work and nurture the young together.
4 .Because the climate is so harsh, cooperation increases the survival rate of the Olympic marmots.
5 .They keep their young at home until they are physically able to survive on their own.
6 .This could explain why the social behavior of the Olympic marmots is so unlike that of the Eastern marmots.