Gray Whale Migration: Ultimate Guide

gray whale migration

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Gray whales are some of the most beautiful and fascinating animals on earth. They have many unique features that make them stand out from other whale species.

They in particular are known for their extremely long migration. In fact, they make one of the largest migrations of any animal on planet earth.

In this post, we’re going to take an in-depth look at gray whale migration and learn how far they migrate, why they migrate, and much more.

Let’s get into it…

Why Do Gray Whales Migrate?

Life for the Eastern North Pacific gray whale begins in the warm lagoons of Baja Mexico.

Their mothers travel there in order to mate and give birth to their calves.

The whales are born into a lifetime of continuous migration and are regularly on the move for a couple of reasons.

First, gray whales migrate North every spring to feast and grow in the rich feeding waters of the Arctic. This allows them to put on the size and fat they need to survive life in the ocean.

This is a survival strategy that has evolved over thirty years and has proven to be effective for gray whales.

Once they have fattened themselves up and fall arrives, they will then migrate back down South to the lagoons of Baja Peninsula, where they were born in order to mate and give birth themselves.

Gray Whale Travel Practices

Once the gray whales are ready to embark on their journey, they segregate into groups according to age and sex, with nursing females leading last.

They only begin this large journey when they are sure that their calves are strong enough to make it, and won’t set off without them.

The migration North is led by the newly pregnant females, a mix of adults and juveniles following closely behind.

Gray whale calves and cows migrate separately, right up against the coast almost in the surf line in order to stay out of the way of a predator, the killer whales.

How Far Do Gray Whales Migrate?

The gray whale migration is one of the longest in the animal kingdom.

Their travel is typically around 10,000 miles round-trip and sometimes up to 14,000 miles.

This is the longest migration of any mammal, with the whales traveling roughly 5 miles per hour and typically covering around 75 miles per day.

Are They Any Dangers During Migration?

Traveling such vast distances does not come easy, and is certainly not without risk.

There are a number of dangers that pose threat to gray whales during their migration.

Killer Whales

One of the dangers during the migration is killer whales, also known as Orca. These incredibly intelligent predators will sometimes make an attack on migrating gray whales, although it is rare.

The killer whales will wait until the second wave of gray whales before attacking, mothers, and their calves.

Although the gray whales typically hug the shoreline, which keeps them protected, there is a stretch of open water that they must cross on their route.

This is where killer whales usually strike. They listen out for the gray whales as they can hear every sound they make.

The killer whales hunt together as a pod and try to separate a gray whale calf from its mother.

Vessel Strikes

Another risk to gray whales during their long migration is vessel strikes.

The area that the whales must pass through can also be filled with vessel traffic that can sometimes result in the whales being bumped into.

Thankfully, NOAA fisheries have collaborated with sanctuaries and the U.S. coastguard to effect changes in shipping lanes during the months of the whale’s migration.

This should help in reducing the number of vessel strikes whilst they migrate, but it’s still a risk that can hinder the whale’s migration.


Gray whales are at severe risk of entanglement because of their large size.

This can mean they get caught up in fishing nets and are unable to swim or break free. Sometimes they even continue to swim with the net cutting into them, which can lead to severe injury and sometimes death.

Sadly the whales are faced with many challenges during their migration, but this is all part of being a gray whale and the risk they take in order to secure abundant feeding grounds.

What Months Do Gray Whales Migrate?

Gray whales typically leave the warm lagoons of Baja at the beginning of February and continue through to April.

This is the best time to see gray whales during their migration off the coast of California, with a large number of whales traveling North up to the Arctic.

Many whale-watching groups set out to spot the gray whales during their migration between these months.

As they often stick to the coast to avoid predators, it’s a great opportunity to spot gray whales in the wild.

Once the gray whales have had their fill and fattened up, they begin leaving the Arctic waters in September, back along the coastline to reach the toasty waters of Baja once again.

They will reach Baja usually in late December, which is the time of year when they begin to give birth to their calves.

Adult gray whales and non-pregnant females also migrate back to the lagoons in order to find a mate.

How Long Do Gray Whale Migrations Take?

During the migration, the whales travel night and day at around 5mph, and in total it takes them around two to three months to arrive at their destination.

Typically covering 75 miles per day, this migration is certainly a long one, in fact, it’s the longest of any mammal in the animal kingdom.

Due to the risks associated with the migration, as well as the reduced feeding opportunities in the tropics, the whales typically fast during the migration.

They are traveling as fast as they can, whilst ensuring they stay with their calves and reduce risk in order to reach the feeding grounds of the Arctic.

Gray Whale Migration Facts

Gray whale mothers are known to be notoriously protective. In the 1900s when they used to be hunted, mothers would attack vessels in order to defend their young.

Mother gray whales and their young are the last to depart the lagoons of Baja, they won’t leave until they are confident their calves are strong enough to make the journey, which is typically from late March-May.

There are approximately 25,000 gray whales that make this migration every year, with some making pit-stops at various locations along the way to feed.

One of these locations is Depoe Bay, where the whales that stop there to feed are known as “Resident Gray Whales”.

gray whale migration

The gray whale migration is one of planet Earth’s greatest wildlife spectacles, and if you have always wanted to witness these whales, the California coast is the perfect place to do so.

Thanks to the ban on whaling as well as the outstanding work from NOAA, the gray whale population is thriving and has a Red List status of Least Concern.

How To Identify A Gray Whale During Their Migration

There are a couple of easy ways to identify a gray whale during its migration if you happen to be on the California coast.


The first is the gray whale’s distinct coloration.

They are covered in barnacles which make them easy to identify and set apart from blue and humpback whales.


The tail fluke of gray whales has a distinct heart shape which is also a good way to identify them during their migration.

Be sure to have a pair of binoculars with you to make the experience better, and be on the lookout for a heart-shaped tail.

Distinct Dorsum

The gray whale does not have a dorsal fin, instead, they have a distinct low hump and have a bumpy appearance.


Although gray whales aren’t quite the gymnasts that humpback whales are, they do tend to breach on their migration which helps whale watchers to identify them.

Be on the lookout for a giant splash in the water and then try to identify the coloration and shape of the whale to be sure you’re following the gray whale migration.

Final Thoughts

The gray whale migration truly is one of the greatest events that nature has to offer. This incredibly long journey is a testament to gray whales and their uniqueness.

These animals really are one of a kind, and if you do happen to live in California or are traveling there in the migration months I would highly encourage you to try and spot a gray whale on its incredible journey.

Thanks for taking the time to read this post and I hope you’ve learned a thing or two about gray whale migration today.

If you have, feel free to share this post with a friend and stick around to learn more about these amazing whales.