Tag Archives: Gray Whales

The Journey of Migration

Every year, many species travel thousands of miles on a journey called migration. Migration is the process by which a species travels from one habitat to another. Animals may migrate thousands of miles due seasonal changes and or to mate, feed and raise their young.

Let’s look at a few migratory species and learn a bit more about them!


Individuals from this species start off their lives as hatchlings on tropical beaches. If they can make the treacherous journey to the ocean, they will spend the next few years avoiding predators and growing larger. Only just above 5% of hatchlings will make it to their first birthday. Scientists have collected very little information on sea turtles’ lifestyle over their first juvenile years (deemed the lost years) however, they likely hide in algal floats and feed on small prey.

Eventually, these turtles can grow up to six feet long and weight over a thousand pounds. Once females are mature, they will return to the tropics to lay their eggs. They don’t lay their eggs just anywhere though- they actually return to the beach that they themselves hatched on! Males spend their entire lives in the ocean, but females will migrate back and forth from feeding to nesting grounds. This journey can exceed 10,000 miles stretching from tropical beaches in places such as Indonesia up to coastal regions including the pacific coast of North America.

We still don’t know exactly how these animals navigate, but they may use the sun or the Earth’s magnetic field. This species has had quite a bit of time to evolve such amazing navigational prowess. Close relatives of the leatherback have existed for over 100 million years!

migration whale

The gray whale migrates farther than any other mammal known to date. In total, this whale travels up to 12,000 miles every year. These whales give birth in tropical waters largely off of Baja California, Mexico. The warm waters provide shelter for their calves keeping them safe from orcas and allowing them to put on blubber. The babies grow quickly eating an average of fifty gallons of milk every day. Over this time, the mother eats little to nothing and looses much of her body mass.

After 2-3 months, the whales begin migrating northward in groups called pods. Their destination is the artic waters of the Bering and Chukchi seas. Once they reach these waters, the whales feast. Gray whales are baleen feeders, which means that they have big toothbrush-like baleen plates instead of teeth. They use these plates to scoop up sediment from the bottom of the ocean and filter out plankton, namely krill. These whales can grow up to 50 feet long and weight 50 tons so they need to eat a lot of food!

migration butterfly

Here on Catalina, we are within the route of the monarch butterfly’s migration. These amazing butterflies migrate up to 3,000 miles every year. Although the migration contains an entirely new generation of butterflies each year, they still nest on exactly the same trees as their predecessors. At Cherry Cove, we found a few monarch chrysalises precariously placed on hoses. We carefully moved these to a homemade habitat and watched as they turned into butterflies. What amazing creatures!

Many animals migrate each through their own remarkable processes. However, climate change is challenging these ancient journeys. Global warming has already begun disrupting migration patterns and will only continue to do so unless species can adapt to the changing climate.

For more:

Migration corridors: http://www.nature.com/news/2011/110622/full/news.2011.379.html

Species changing migration routes and migrating to new areas due climate change: https://www.neefusa.org/weather-and-climate/marine-species-move

For teachers: lesson on migration:

  1. https://www.nationalgeographic.org/activity/why-animals-migrate/
  2. https://www.nationalgeographic.org/activity/marine-migration/










Written by: Talia Niederman

Massive Migration of Gray Whales

Gray Whales have the longest known migration of any mammal traveling a total of about 10,000 to 14,000 miles! This migration typically starts in the Bering, Chukchi, and Beuafort Seas and ends around the coast of Baja California. This massive migration is quite the feat and it typically takes two to three month just to travel one way! This means that gray whales spend almost half a year solely dedicated to their migration. So why do these massive marine mammals migrate so far? Proper food and breeding grounds are extremely important for the survival of Gray Whales. Therefore these two factors are driving forces behind such a large migration.

GrayWhaleMigration1Gray Whales typically spend their summers in the cold, nutrient rich waters of the north, in particular the Bering, Chuckchi, and Beuafort Seas, where they can find ample amounts of food. They have around 130 to 180 plates of baleen on each side of their upper jaw and utilize this baleen in order to catch their food. Gray Whales have developed the nickname “mudsuckers” over the years due to the fact that they love to eat invertebrates found on the muddy and sandy ocean floor. They will typically feed on just one side of their mouth making the either right sided or left sided feeders; kind of like how us humans are either righties or lefties. While feeding they utilize their baleen to filter out water and sediment while keeping the delicious benthic invertebrates trapped in their mouth.

Gray Whales start migrating south during the beginning of September and October and will start arriving in Baja by mid February and March.

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GrayWhaleMigration6Once in Baja they will begin to mate and calve a new generation of whales. The warm waters of Baja provide a safe environment for the mothers to nurse their calves. In the first few months of their life gray whale calves will be nursed milk that is about 53% fat; this milk is so fatty that is has a consistency similar to cottage cheese! During the two to three months spent in the warm water of Baja young gray whales grow stronger and build up an ample amount of blubber for the colder waters of the north.

The migration back to northern waters typically begins in late March and mid April. During this northern migration mothers will travel close to shore to keep their young safe from potential predators and dangerous water.

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Written By: Alex Feltes


Gray Whale. National Audubon Society: Guide to Marine Mammals of the World. 2002.


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