Do blue whales eat anything besides krill?

While krill is the primary food source for blue whales, they can and do eat other things, especially when krill is scarce. These include:

* Other crustaceans: This includes copepods and small shrimp-like creatures.

* Small fish: Blue whales have been observed eating small fish like herring, anchovies, and sardines.

* Squid: These are a relatively rare part of their diet, but blue whales have been known to eat them.

It's important to remember that blue whales are filter feeders, meaning they strain food from the water using baleen plates. This limits them to relatively small organisms. While their diet is primarily krill, they are opportunistic feeders and will take advantage of other food sources when available.