Worksheet B2d 4

Predator–prey game

Lemmings are small hamster-like animals that live in the Arctic. Their population size can increase and decrease dramatically. Snowy owls feed on lemmings. The game follows the change in population of owls and lemmings. Play the game with a partner and then answer the questions below.

Rules of the game  Work in pairs with one person acting as the lemmings, and the other as the owls.  Start with 30 lemmings and three owls.  The lemming person writes 30 ‘X’s, in pencil, on the Arctic map in different squares.  The owl person calls out a number from 1 to 50, and:  if there is a lemming ‘X’ in the square the lemming is eaten (rubbed out)  if there is no ‘X’ it was an unsuccessful hunt.  Each owl has one guess (hunt) per round – so three owls equals three guesses.  At the end of the round, count up the number of lemmings and add on four more for reproduction. Remember to add the extra four to squares on the map.  For every lemming eaten, an owl is added to the score. For every two unsuccessful hunts an owl is lost.  Record the results at the end of each round in the table.  Continue for eight rounds. Remember, if the owl number changes so does the number of guesses in the next round.  At the end of the eighth round, a cold winter results in less food for the lemmings. Some of the lemmings starve to death. Rub out half of the lemming population!  Continue for another eight rounds.

Hunting round Number of lemmings Number of owls At start 30 3 1

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8 Worksheet B2d 4 Continued

Hunting round Number of lemmings Number of owls Rub out half the lemmings as they have starved to death! 1

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Arctic map This is a map of where the lemmings and snowy owls live. Mark on your first 30 lemming ‘X’s. At the end of each round remember to rub out the ones that got eaten and add four new ones. Worksheet B2d 4 Continued

1 Plot a graph of your results.

2 Write on a separate piece of paper about the changes in the number of lemmings. Include in your answer:  how the number changes  why the number changes. Worksheet B2d 5

Compete or die word search

There are nine words connected with the lesson Compete or die hidden in the word grid below. The words may be horizontal, vertical, forwards or backwards. See if you can find all the words.

c o m p e t e e r y l o u z h k j k h u e p t t c o p r e y a h u a i t g m r r n g a l n g l p x n e d l e d t l o s n r r i w r v n p d o s e s j p x u u t i p e m r j r a l s t e w s m d o e a s i c e d n r t e t a t i a p a r a s i t e e a y m c d f o h p s f t k r e r n g m a v u h s r e b v o t t d d s p c t r c B2d 2

Technician’s notes

Worksheet B2d 4 – Predator–prey game

Equipment (per pair):

 graph paper

Class activity – Parasites and cleaner species

Provide pictures of parasites and cleaner species:  tapeworm  flea  oxpecker  sharksucker B2d 2

Answers

Worksheet B2d 5 – Compete or die word search

c o m p e t e l u h e t c p r e y a u i n a n p e l o n r i p o s s u i p m r l t e o a i c t t t i p a r a s i t e e d o p s e n m r o p c