Proximate and Ultimate Causes of Animal Behaviour

The beewolf wasp(Philanthus triangulum)

Beewolf wasp burrows

Niko Tinbergen: one of the founders of ethology

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The Scientific Method

• Observation and causal question

• Hypothesis

• Predictions

• Test of predictions

• Conclusion

The Scientific Method• Observation and causal question: Beewolves find

the entrance to their own nests. How do they do it?

• Hypothesis: They use local landmarks as cues

• Predictions: If they use local landmarks then

manipulating those landmarks should mislead them

• Test of predictions: Experiments

• Conclusion: Yes, local landmarks are used by

beewolves as cues in finding own nest

Black-headed gull

… and its chicks

The Scientific Method• Observation and causal question - black headed gulls

remove eggshells. Why did black headed gulls evolve

behaviour of eggshell removal?

• Hypothesis - maybe this behaviour helps parent gulls to

conceal their offspring from predators

• Predictions - if so, broken eggshells should help predators

find food

• Test of predictions - experiment

• Conclusion - yes, eggshell removal

appears to help parent gulls conceal

offspring from predators

Proximate causes Ultimate causesof behavour

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Oystercatcher

Black-headed gull

Kittiwake

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OystercatcherSolitary nestingNest predatorsImmediate eggshell removal

Black-headed gullGroup nestingNest predation presentDelayed eggshell removal

KittiwakeGroup nestingNo nest predatorsNo eggshell removal

Why do

babies cry???