Here are some of the things we wondered about the report:

Who was the observer, and how well can she or he identify gray whales?
It's important to ask questions about observers and their data. For instance, the observer might really have seen another type of whale. How could we try to answer our question?

Why aren't the gray whale nursery lagoons as warm as usual?
The observer in Mexico thinks that a multi-month climate event called El Niño caused the lagoon waters to get colder. (Another phase of this climate event, called La Niña, causes cooling.)

We wondered, "Was this really happening?" Last month scientists said: The current La Niña event, which is marked by a cooling of the sea surface in the central and eastern Equatorial Pacific, has strengthened in recent months. It is expected to continue through March of 2008.

How will this affect the pregnant mothers and calves?
No one knows for sure. Could it affect the new mothers' milk supply or the babies' growth rates? Would all that extra swimming weaken the whales for the return trip? Will the extra travel time spread the migration out and lengthen the return trip to Alaska? What were your thoughts?

What else could explain why some gray whales would swim all the way to the Sea of Cortez?