Living Environment/Ecology

[venomous1399]

What is the problem and the variables in the experiment "Are We There Yet? Testing How Migratory Birds Navigate"?

[deleted-132180]

Hi there,

This experiment is a bit complex and has several different questions weaved into it. Seems like the big broad question the project is asking is whether these birds have an internal compass and/or map. If these birds have an internal compass only, they will know the general direction they're going in, but not where their final destination exactly is. So, theoretically, if these birds were moved off course, they'll keep flying south since they known that's the direction they're supposed to fly to reach their wintering grounds, but they'll never reach their wintering grounds because they were moved off course. However, if these birds also have an internal map in addition to an internal compass, they'll be able to reach their wintering grounds even if they were moved off course. Does that make sense? The background portion of the project explains this phenomenon pretty well.

Now, the experiment these scientists did is displace some birds (15 adults, 15 juveniles) from their normal migratory route in Sunnyside, Washington all the way across the country to New Jersey. Now, the question is, if these birds were displaced from their normal route, where will they fly?

Before I get into the questions of this project, I wanted to mention that for identifying variables in an experiment, please check out this really great page on Science Buddies: https://www.sciencebuddies.org/science- ... evariables. It explains really well how to identify independent, dependent, and controlled variables within an experiment. An independent variable is something that is changed by the scientist. The dependent variable are the observations you see upon changing the independent variable. Controlled variables are things that a scientist wants to remain constant to make sure that you can conclude that the observations you make are due to the changes you make in the independent variable, and not due to other parameters. Does that make sense?

First, let's look at the birds together as a whole and not divide them up as adults and juveniles. The main question would be: Where will these birds fly when they are displaced from their original location? The procedure mentions drawing three hypothetical travel lines: 1) They will travel back to Sunnyside. 2) They will travel south, but will not reach their wintering grounds. 3) They will reach their wintering grounds. Now, when you think of the independent variable, what is changing? You've thrown the birds off course, so what has changed is their initial "start" point: Birds that are "starting" in Sunnyside, and birds that are "starting" in New Jersey. Your dependent variable would be where these birds will go. Where will the birds which normally start from Sunnyside go? If they behave as they typically do, you would expect them to fly south to reach their wintering grounds, correct? Now, where will the birds starting from New Jersey go? Does changing the variable of where these birds "start" change the fact of whether or not they'll reach their wintering grounds? Think about these questions as you analyze the data. Does all of this make sense?

Now... the scientists added in a second layer of complication. They wanted to know if adults and juveniles behave differently when they are displaced from Sunnyside to New Jersey. That is, will the adults and juveniles end up flying to different locations, or does age/experience not matter and they will both end up at the same location? What are the independent and dependent variables for this question?

Think about these things as you analyze your data, and please feel free to post back if you have anymore questions. If I have explained something wrong or in a way that is way too confusing, other experts please feel free to chime in and correct me.

Best,
Connie