How living in groups helps animals survive

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Ducks at day 10 (model data)

   group	ducks at start	ducks lost by day 10
   in flocks	30	3
   alone	60	24

2. 1.

   Milo reads the model data. Which statement compares how likely a duck was to be lost by day 10?

   • Ducks in flocks were 4 times as likely to be lost: 10% against 40%
   • Ducks alone were 8 times as likely to be lost: 24 ducks were lost alone against just 3 in flocks
   • Ducks alone were 4 times as likely to be lost: 40% (24 of 60) against 10% (3 of 30)
   • Ducks alone were 30 times as likely to be lost: 40% − 10%

3. Two dances for one patch (the sun moves 15° clockwise each hour) (model data)

   dance	time	sun's compass bearing (°)	angle clockwise from vertical (°)
   dance A	12:00	180	40
   dance B	15:00	225	?

4. 2.

   Pia uses the model rule: bearing to the patch = sun's bearing + angle. Dance B is for the same patch. What angle should dance B show?

   • 5° counterclockwise from vertical, since 220 − 225 = −5
   • 40°, the same as dance A, since the patch has not moved
   • 45°, the amount the sun moved
   • 5° clockwise from vertical, since 225 − 220 = 5

5. Two waggle dances (model data)

   dance	waggle run (s)	angle clockwise from vertical (°)
   dance 1	2.0	40
   dance 2	2.0	130

6. 3.

   Ren reads two dances from one hive at the same time, using 1 s of run = 400 m. Which statement does the card support?

   • The bees found different resources, since the angles differ
   • Both patches are 800 m away, but in directions 90° apart
   • The two patches are the same place, since the runs match
   • Patch 2 is farther, since its angle is larger

7. Five dances for one patch (model data)

   dance	waggle run (s)
   1	2.3
   2	2.4
   3	2.5
   4	2.6
   5	2.7

8. 4.

   Zee reads five dances for one patch, using 1 s of run = 400 m. Which statement about the patch is best supported?

   • Between 2.3 m and 2.7 m away
   • About 920 m away, because dance 1 settles it
   • Likely about 1,000 m away, within about 80 m either side
   • Exactly 1,000 m away, since the middle run is 2.5 s

9. Use the table

   A male's record (shares from Gilbert et al. 2006; the days are model data) (model data and Gilbert et al. 2006)

   measure	value
   days recorded	80
   share of time huddling	38%
   share of huddling time above 20 °C	13%

10. 5.

    Tala applies the published shares to a model record. About how many hours was the temperature above 20 °C?

    • About 30 hours, from 38% of 80
    • About 95 hours: 80 × 24 × 0.38 ≈ 730 huddling hours, then 13% of that
    • About 730 hours, the time spent huddling
    • About 10 hours, from 13% of 80

11. Two birds (model data)

    bird	air around it (°C)	gap from 38 °C (°C)
    alone	−17	?
    in a huddle pocket	20	?

12. 6.

    Ari uses the model rule: heat lost is proportional to the gap from a bird's 38 °C. How does a bird in a 20 °C pocket compare with one alone in −17 °C air?

    • No heat lost, since 20 °C is above 0 °C
    • About 3 times as much heat lost: 55 °C against 18 °C
    • About one third as much heat lost: a gap of 18 °C against 55 °C
    • About half as much heat lost: 20 °C against 38 °C

13. Use the table

    The huddling study (data: Gilbert et al. 2006)

    detail	entry
    birds fitted with data loggers	8
    what the loggers recorded	temperature around each bird
    colonies in the study	one

14. 7.

    Bo reads the study details. What can the study of 8 birds support?

    • It shows what happened to these 8 birds; it cannot fix a value for every colony
    • It shows huddling raised the birds' body temperature to 37.5 °C
    • It shows every emperor penguin colony huddles for 1.6 h at a time, since the 8 birds are enough to speak for them
    • It shows nothing, since any study of 8 birds is useless

15. Study card: minnows (model data)

    part of the study	entry
    fish in groups of 10	40 fish in a shaded tank
    fish alone	40 fish in a bright tank
    measured	fish surviving at day 10

16. 8.

    Esme reads the study card. Which flaw most weakens the claim that groups raise survival?

    • Light differed between the tanks too, so group living is not the only change
    • Survival at day 10 cannot be used, so the study fails
    • Forty fish is always too few, so the study means nothing
    • Fish alone act as the control group, which makes the whole result invalid for a comparison

17. Four study plans (model data)

    plan	how birds are placed	trials per flock size
    plan 1	the healthiest birds go in the biggest flocks	1
    plan 2	birds are assigned to flock sizes at random	6
    plan 3	birds choose their own flock size	6
    plan 4	birds are assigned at random	1

18. 9.

    Jun reads four plans. Which plan best tests whether flock size changes survival when birds differ?

    • Plan 3: birds choose, so the result matches real life closely
    • Plan 2: random assignment evens out bird differences, and six trials show the spread
    • Plan 4: random assignment alone is enough, with a single trial each
    • Plan 1: the healthiest birds make the biggest flocks, so differences between sizes are clearest

19. Pond survey (model data)

    pool	group size	share surviving (%)	shelter plants (%)
    pool A	4	55	5
    pool B	12	75	40
    pool C	30	88	80

20. 10.

    Kira reads a pond survey. Does the table show that bigger groups cause better survival?

    • No: a survey cannot be used as evidence
    • Yes: survival rises at each step in group size, so bigger groups cause better survival
    • No: shelter rises with group size, so shelter may explain the survival
    • Yes: 88% in pool C is the highest, so groups of 30 work well