Beeping Collars and Vineyard Sheep

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Beeping Collars and Vineyard Sheep

Use farm records to explain how sense signals lead to behavior and memories.

The collar records

Read the passage and Table 1, then answer the questions.

A Fence You Cannot See

1Ridgeline Farm grows wine grapes and hay and raises beef cattle and sheep. The farm, the people and the numbers here are made up, but they are based on real farm studies. This summer, sixth grader Wren Castellano worked with farmer Aurelio Mendes and kept records for two projects about how farm animals sense the world and learn.

2The first project tested a virtual fence on a hillside pasture. Each of the 10 cows in the herd wore a collar with a small speaker and a satellite location finder. Mr. Mendes drew a boundary line on a map on his tablet. When a cow walks up to the line, its collar plays a beep. If the cow turns back, nothing else happens. If it keeps walking toward the line, the collar gives a mild electric pulse, weaker than the shock from an ordinary electric fence. Each collar counts its beeps and pulses.

3The second project was in the vineyard. Sheep can graze the grass and weeds between the rows of vines, but many sheep also like to eat grape leaves. Before the sheep went in, the farm's vet trained half of the flock. Each of those sheep was offered fresh grape leaves, and after it ate some, the vet gave it a safe dose of a substance that upsets the stomach for a few hours. The other half of the flock was not trained.

4To check the training, the vet put each sheep alone in a pen for 30 minutes with a pile of fresh grape leaves and a pile of grass, then weighed what was left. Each group had 10 sheep. The trained sheep were tested a week after training and again three months later.

Table 1. Virtual Fence Records for the Herd (10 cows)
Day	Beeps	Pulses	Beeps with a pulse (%)
1	40	20	50
2	30	9	30
3	25	5	?
5	20	2	10
7	20	1	5

1.

On Day 3, what percent of the beeps were followed by a pulse? %

2.

From Day 1 to Day 7, the share of beeps followed by a pulse fell from 50% to 5%. What does this change show about the cows' behavior?

A. The cows stopped feeling the pulses, so they walked through the line without turning.B. More of the cows turned back at the beep, before any pulse was given.C. The cows walked up to the line more often each day, but the collars ran low on power.D. The cows heard fewer of the beeps each day, so fewer of them turned back in time.

3.

Which explanation for the change in Table 1 fits the passage best?

A. The pulses made the cows' leg muscles weaker, so they walked less each day.B. The cows' eyes learned to see the boundary line on the grass after a few days.C. The beep hurt the cows' ears, so from the first day they turned away from the sound.D. The cows' brains stored a memory linking the beep to the pulse, so the beep alone made them turn.

4.

On Day 7, a cow hears a beep and turns back. Circle each step that happens inside the cow's body.

5.

On Day 8, a young cow from another farm joins the herd wearing a new collar. It has never heard the beep before. Which prediction fits the data best?

A. It would likely avoid the line before its first beep, since it can see the other collars.B. It would likely get pulses less often than the Day 7 herd, since it is new to the pasture.C. It would likely get pulses more often than the herd at first, like the herd on Day 1.D. It would likely get pulses as often as the Day 7 herd, since cows are born knowing the beep.

6.

On Day 9, the speaker in one cow's collar breaks, but the pulse still works. Which prediction fits best?

A. That cow would likely get as many pulses as before, since the beep and pulse reach the same receptors.B. That cow would likely stop going near the line, since a broken speaker makes the collar heavier.C. That cow would likely get more pulses than before, since no beep comes to warn it first.D. That cow would likely get fewer pulses than before, since the pulse alone is a stronger warning.

The sheep in the vineyard

Use paragraphs 3 and 4 and Table 2 to answer the questions.

Table 2. 30-Minute Pen Tests (average per sheep)
Group	Grape leaves eaten (g)	Grass eaten (g)
Trained, 1 week later	4	310
Not trained	160	280
Trained, 3 months later	10	300

7.

The sheep that were not trained ate how many times as much grape leaf as the trained sheep did 1 week after training? times

8.

The trained sheep ate about as much grass as the sheep that were not trained. What does this result suggest?

A. The training changed how the sheep treated grape leaves, not how they ate in general.B. The grass in the pen had a grape smell, so both groups ate the grass first.C. The trained sheep were hungrier, so they ate more grass to make up for the leaves.D. The training made the sheep too sick to eat, so they took in less food overall.

9.

A trained sheep sniffs a grape leaf, nibbles it and walks away. Which sense receptors most likely sent the signals its brain used?

A. Smell and taste receptors, whose signals the brain matched to a memoryB. Touch receptors in its hooves, which feel the vine roots under the soilC. Sound receptors in its ears, which pick up the rustle of the grape leavesD. Receptors in its stomach, which sense the leaves before the sheep bites

10.

Three months after training, the trained sheep ate g more grape leaf on average than they did 1 week after training.

11.

Which conclusion about the trained sheep's memory do the 3-month results support best?

A. The memory was passed on to the untrained sheep, since those sheep ate 160 g of leaves.B. The memory lasted at least 3 months, since they ate 10 g of leaves compared with 160 g.C. The memory got stronger, since they ate fewer grape leaves at 3 months than at 1 week.D. The memory faded away, since they ate more grape leaves at 3 months than at 1 week.

12.

Wren's cousin says, "The cows and sheep just react to whatever is in front of them. Their brains do not store anything." Argue against this. Write a claim, give evidence from both tables, and describe the path from a stimulus to a behavior for one of the animals.