In the experiment described in the scenario, what’s the variable?

Variables,control,conclusion and finally scientific theory

Change in speed or direction : )

That depends. cause the owl finished it in one lick

The population of unionid mussels decreased after zebra mussels were introduced. zebra mussels competed with the unionid mussels for food. the zebra mussels were able to displace the unionid mussels, allowing the zebra mussel population to increase  over the years. the unionid mussel population decreased because  of lack of food.