Young Ring-billed Gull

Photo by Kevin McGowan/CLO

Taking Terns

Eating Habits of Gulls

By Alexandra, Ben, and Peter, Grade 8
Rye Junior High School, Rye, NH
Ms. Ellwood

Introduction

For our experiment, we are laying out three types of food on the beach: lettuce, hot dogs, and bread. We will tally the number of gulls that select each of the different types of food. The null hypothesis is that the gulls will not be attracted to one food type more than another. The alternative hypothesis is that the gulls will be more attracted to one type of food. Our prediction is that the gulls will be attracted to the hot dogs because they are more tasty and the gulls will find them more tantalizing.

Experimental Design

Prepare the materials at home. Put all of the food into separate plastic bags. Next, go to the testing location—Wallis Sands Beach in Rye, New Hampshire. Lay the food directly on the sand approximately 15 inches apart. Go set up "camp" about 30 feet away. Set the watch for 10 minutes and tally the number of gulls you see at each feeding site and record it on the data sheet. After 10 minutes, collect the food from the beach. This experiment should be repeated at least eight times at 4:00 p.m.

Materials Needed

• Two slices of white Wonder® bread
• One Oscar Meyer® hot dog
• An apple-sized amount of iceberg lettuce
• Tally sheet and pencil
• Watch
• Measuring tape

Figure 1. Food type versus number of gulls

Results

We attempted to determine the statistical significance of our data. A larger data set would be more reliable.

The math supports our alternative hypothesis. The type of food does affect the number of gulls that eat it.

We think that to improve the data, we should redo the experiment. Even though we did the experiment eight times, we only saw gulls on four of the days.

Discussion

When we entered our data into the statistics check, it came out that our alternative hypothesis was supported, although we believe some information is missing. If we were to repeat our experiment, we would test it several more times to get a wider variety of results.

We really enjoyed testing our experiment. We loved when we would get more than 50 gulls gathered around the food and how they would start calling for more when they had finished off the first batch.

Belted Kingfisher

By Bearon, Grade 4
Squamish Elementary School
Squamish, WA
Ms. Jackson

The Belted Kingfisher

By Max, Grade 4
Manor School, Fairfax, CA
Ms. Honda

The master fisher
Of the river
Doesn't use a rod.
With its beak,
It dives in the creek,
And pulls out a fish,
To take back to its young.
It should,
I think
Be a bird of prey.
Its list of food
Is far too long to say.

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For permission to reprint all or part of this article, please contact Laura Erickson, editor, Cornell Lab of Ornithology, 159 Sapsucker Woods Rd., Ithaca, NY, 14850. Phone: (607) 254-1114. email: lle24@cornell.edu