CEDARBURG, Wis. » While visiting family in Wisconsin this week, I took my computer to a coffee shop advertising free Wi-Fi to check out the news from home.

On http://www.starbulletin.com I read about a killer whale that washed up on a Kauai beach. The animal was so weak and emaciated, officials had to euthanize it. On another page, I read that seven killer whales from Puget Sound are missing and presumed dead.

Is there a connection between these two events? I wondered. And then I got my money's worth of pumpkin spice lattes as I searched the Internet for information about these magnificent creatures.

Killer whales swim in all parts of all the world's oceans, including the Arctic and Antarctic. These widespread whales, also called orcas, are all one species. Biologists, however, separate the North Pacific orcas into distinct groups.

The killer whales of Puget Sound are called residents because they stick to one area and have a small home range. Members of resident orca pods are related to one another and stay together for life. These orcas eat fish, mostly salmon.

Other killer whales, called transients, hunt along the northern coastal waters of North America, swimming large distances up and down the West Coast, in pods of 10 or less. Unlike resident orcas, transient orcas change pod members and aren't necessarily related to one another.

Transient orcas eat whales, dolphins, seals and sea lions exclusively. These orcas aren't interested in eating terrestrial animals, including us. Orcas have ample opportunities to attack people swimming, kayaking and boating, but they do not.

A third type of killer whale is the offshore orca. These whales swim offshore and also visit coastal waters, overlapping the ranges of the other two types. Like the resident orcas, offshore orcas eat fish.

All three forms of killer whales differ slightly in shape, color patterns, behavior and genetics. They do not mix pods or interbreed.

Not much is known about the 200 or so orcas that swim in and around Hawaii waters; they might be their own distinct group. Given the scarcity of food in our warm waters, Hawaii's orcas probably eat anything they come across. Killer whales in Hawaii have been seen eating a humpback whale and squid.

The orca density is low in Hawaii, but occasionally lucky boaters spot these distinct whales. And sometimes we see them stranded on our beaches. In 2004 another orca beached itself and died on Lanai.

Because of their enormous ranges, orcas are extremely difficult to count. These whales aren't currently considered endangered, but because the world's stocks of fish, whales, seals and sea lions are so greatly diminished, researchers believe the orca population is declining.

The jury is still out on the cause of the whale deaths in Hawaii and Puget Sound, but the jury is in on the world's oceans: We've overfished them so much that the marine food chain might be permanently damaged. It's no leap, therefore, to suspect that scarcity of food could be the cause of the orcas' recent demise.

Even if starvation isn't the reason these particular orcas died, the possibility is enough to make me seriously consider giving up fish.

I won't, however, give up designer coffee. Without it, I can't keep up with the news from home.