Dr. Estes and his group hypothesized (made a claim) that the cause of the sea otter decline was due to increased predation by killer whales. This was an unusual idea, since killer whales and sea otters had been observed
together in Alaska for decades with no obvious interactions occurring between them. The first time a killer whale
was observed attacking a sea otter was in 1991. Nine more attacks were observed in the next seven years and it
was these attacks that finally led Dr. Estes and his colleagues to propose their hypothesis. To test this hypothesis,
the scientists needed to have information about the killer whale.
1. Make a list of at least three types of information (evidence) about killer whales you believe the scientists
might need in order to test their hypothesis that increased predation by the whales was the cause of the sea
otter decline