Gray Whale Diet: What Do Gray Whales Eat?

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The impressive gray whale is renowned for its incredibly long migration and its unique appearance.

Covered in barnacles and making an incredibly long 10,000 – 14,000 mile-long migration each year to the Arctic waters, the gray whale is, without doubt, one of the most impressive mammals on earth.

But what do gray whales eat?

Gray whales mostly feed on amphipod crustaceans, which are incredibly small shrimp-like creatures that can be scooped up in abundance by the gray whales’ mouths.

Let’s take a closer look…

What Do Gray Whales Actually Eat?

Although gray whales eat very little whilst on their long migration, they may come across and eat schooling squid, krill, crab larvae, ghost shrimp, plankton, and small fish.

These gigantic whales typically eat amphipod crustaceans when they reach the abundant waters of the Arctic.

Feeding occurs almost exclusively during the summer months and allows them to survive from their fat reserves during the winter.

They are opportunistic feeders which means they will take food from a variety of sources. They eat a little like cattle in an open field, in the sense that they will eat one area down and then move on to the next.

How Do Gray Whales Catch Their Food?

Gray whales are baleen whales which means they have plates of whalebone on each side of their upper jaw that they use as a filter to extract food.

These whales are some of the only whales that consistently feed off the bottom of the ocean.

They use their baleen and roll on their side to suck up sediment which will catch plankton, larvae, small fish, tube worms, and anything else that is down there.

From there they use their baleen to filter out the water and sediment and shoot it out of the other side of their mouth, whilst the food is caught in the baleen.

It’s a pretty impressive feeding strategy that has worked extremely well for gray whales.

Check out this great drone footage of a gray whale feeding at Laguna Beach:

An interesting fact is that scientists believe that they can tell if a gray whale is left or right-handed by which side the barnacles grow on them.

When the whales roll on their sides, this is when the barnacles stick to them, and whichever side has barnacles on is the side that the whale prefers to scoop food up with.

When observing gray whales you can usually see that one side is covered in barnacles and the other is relatively clean, so whichever side has the barnacles is likely their preferred side to scoop food up with.

Do Gray Whales Eat Fish?

Although gray whales were once thought to only use the filtration method for feeding.

According to new research, Lindberg believes that gray whales are now using a variety of feeding tactics that include eating fish such as Herron, but also krill.

Some gray whales even take a short pit stop during their incredibly long migration in destinations that are rich in Herron and Krill to feed, such as Vancouver, Canada.

This varied diet is what makes the gray whale so versatile, and has allowed them to survive for millions of years and come back from near extinction.

Are Gray Whales Carnivores?

Yes, gray whales are carnivores as they eat fish, krill, squid, and other animals that live near the bottom of the ocean.

Technically these whales are Omnivorous as they can also consume some plants that are on the ocean floor when scooping up their food.

Whales are warm-blooded mammals, which means they need a high amount of calories to keep themselves warm and power their bodies.

During the gray whale migration, they typically fast and don’t eat at all, solely relying on the fat stores that they have gained.

If the gray whale was not a carnivore, it would be very difficult for them to get the nutrients and calories they need to develop those fat stores and survive for sometimes months without eating.

How Much Do Gray Whales Eat Per Day?

Gray whales typically spend four to six months in the summer feeding intensely and fattening themselves up, but when they migrate back South their eating drops whilst they mate and give birth.

During the time the gray whales are in the Arctic, where food is plentiful, they will typically eat about 4% of their total body weight each day.

This well exceeds their daily requirements and ensures they fill themselves to the brim in order to run on fat reserves whilst they migrate back to the Baja lagoons.

Gray whales eat about 150,000kg (340,000 lbs) of food during a 140-day feeding period in the Arctic, with a daily average of around 1100kg (2400 lbs).

It’s estimated that it takes around 300kg (660 lbs) of food to fill a gray whale’s stomach.

That’s a lot of food! Enough to allow them to gain about 16 – 30% of their total body weight during the feeding season.

However, when the whales are out of feeding season and are swimming South to mate, they eat much, much less, often not at all.

Final Thoughts

So, what do gray whales eat? Mostly, amphipod crustaceans but also squid, small fish, krill, and just about anything they can get their metaphorical hands on.

These whales are incredible survivors, and they do so by eating a varied diet that comes from many different sources.

Gray whales eat in summer, when they migrate north to the Arctic, rich feeding waters. They overeat to ensure they put on as much weight as possible, often between 20 – 30% of their total body weight.

This extra weight gain then sustains them for when they make the migration back down South to the warm Baja lagoons where they will mate and give birth.

Gray whales are some of the most fascinating whales because of this incredibly long migration. They are a type of baleen whale that uses a filter-feeding method to secure their food from the ocean floor.

Hopefully, you’ve learned a thing or two today about what gray whales eat and how much they eat.

Thanks for taking the time to read this post and I hope it’s been useful to you.