Are Cormorants Invasive?

Cormorants are not invasive birds. These birds have been incorrectly blamed for being invasive, causing a reduction in the population of fish, and being brought to the West Coast from Asia when in reality, there are 6 species native to the US that do not overhunt fish.

These giant birds might seem intimidating and harmful to the environment. However, we can only judge something if we are fully aware of all the correct facts. This is why, in this article, you will learn more about these birds, where they come from, and whether they are actually found to be invasive or not.

How Common are Cormorants?

You might only have heard of cormorants if you live near the West Coast or inland waters which is why you must be curious. Cormorants are a widespread species of birds.

These huge birds are found near rivers and lakes alone but are seen in groups when seen in inland areas. It mainly feeds on the sea, which is why it is found there.

There are about 36 different species of these birds all around the world. The size of these birds varies depending on the species of cormorants.

The estimated number of cormorants around the world is about 372,300 pairs. This means these birds are very common and found on the seashores.

Are Cormorants Invasive Species?

When birds are referred to as an ‘invasive species,’ people think they have been intentionally introduced to a region.

This eventually leads to people believing that these birds should not be here and breed there because they spread pests and diseases that mess up the environment.

There is a common misconception that cormorants are also one of the invasive species on earth that have been introduced to the west coast from Asia.

However, this is different. There were already 6 species that were native to the West Coast, meaning that these birds have not been forcefully introduced to the West Coast.

It has also been found that these birds are not messing with the environment of North America because they only eat about a pound of fish and are not depleting the amount of fish in the sea.

Cormorants are, therefore, some of the least problematic birds on this planet and are definitely not invasive.

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Are Cormorants Endangered?

Cormorants have been through a very interesting cycle over the past century. The number of cormorants was at its peak during the early 20th century.


These birds stayed at the great lakes until the 1950s when their number started to decline.

Now, cormorants are almost on the brink of extinction, but their number has increased drastically due to freshwaters.

This means that these birds were once endangered however the number of cormorants was increased back successfully. Hence, they are not an endangered species of birds anymore.

Are Double-Crested Cormorants Endangered?

Just like cormorants in general, the double-crested cormorant, a black bird with a tiny yellow patch on its face, was also once endangered.

In the 1960s, this cormorant bird was nearly placed on the list of endangered animals. However, just like we mentioned before, these double-crested cormorants, also known as water turkeys, were able to make a great recovery.

So, double-crested cormorants are no longer endangered.

Can You Shoot Cormorant Birds?

Why would you need to shoot one if people choose not to eat cormorants? Well, if you’re a hunter and are wondering whether it is alright to shoot a cormorant, let’s check the rules and regulations people have in areas where cormorants mostly live.

Even though cormorants aren’t such rare birds, shooting a cormorant has laws under the 31st section of the Fish and Wildlife Conservation Act.

Since the droppings of cormorants are rich in ammonia, they cause certain damage to the environment. These bird droppings kill trees and harm vegetation in certain areas.

These reasons are still not an excuse to shoot these innocent birds. Only property owners are permitted to do so.

Do People Eat Cormorants?

Cormorant meat has been considered unhealthy due to the fishy diet they have. Due to water pollution, fish have been consuming harmful chemicals, which have increased mercury levels in fish.

People avoid eating cormorant meat nowadays due to the tough meat and how difficult it is to pluck their feathers and prepare its meat. People in the northwest have stopped eating cormorant meat. Hence, people don’t eat cormorant meat.

What Animals Prey on Cormorants?

Cormorants are huge birds that mainly eat only fish. When it comes to animals that eat cormorants, we can only imagine bigger animals eating cormorants.

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So, let’s get to the real answer. Gulls, jays, crows, and crackles are all animals that eat cormorant eggs and their chicks. Some other animals that eat cormorant chicks are raccoons, foxes, and coyotes.

Cormorant on island

Meanwhile, animals that mostly eat the cormorant bird themselves include brown pelicans, some species of sharks, bald eagles, horned owls, and caimans. These animals can be found near the habitats of cormorants and feed mostly on cormorants. 

Are Cormorants Protected?

Even though cormorants aren’t rare birds, there is still a need to protect cormorants. These birds are protected under the eyes of some organizations.

Why do Cormorants need to be Protected?

Every single organism on earth has a purpose. Some animals may not seem important, but they all have a huge impact on the ecosystem. Just like that, these birds need to be protected too.

Cormorants impact the species of fish because of their diet. They also impact other birds through the competition of vegetation and nesting.

How are Cormorants Protected?

Cormorants are protected under many laws. Double-crested cormorants are protected under the Migratory Bird Treaty Act, also known as MBTA.

This act protects these birds by prohibiting killing, selling, trading, and capturing them. Meanwhile, other species of cormorants are protected under many such laws that have four international conservation treaties.  

Are Cormorants Bad and Why?

Many animals are considered bad due to the diseases they spread and the average number of people and other animals they kill. The top worst animals include mosquitos, snakes, scorpions, etc.

However, this list does not include cormorants. These birds can be considered bad because they cause a lot of damage to their surrounding environment due to the following reasons:

  • Hunting habits
  • Acidic droppings and
  • Guanos

These facts eventually damage people’s properties and even vegetation, including huge trees.

How Long do Cormorants Live?

Surprisingly, cormorants live very long lives. They have a lifespan of about 28 to even 30 years! Unfortunately, this is not the case for every cormorant born due to a very high mortality rate. Almost 40% of these birds only survive as soon as they leave their nest within the first year.

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What is the Purpose of a Cormorant?

According to what we have learned so far, cormorants are quite problematic and damage the environment.

But, if we ignore all that, these birds are quite important to the ecosystem and even play an important role in some beliefs.

These birds are considered a symbol of indulgence and nobility. These birds dive into the water to catch fish, sea snakes, and eels which helps maintain the ecosystem.

In modern times, cormorants have also been considered a good luck charm for many fishermen as they help bring the fisherman a bonus catch.


Can you Cull Cormorants?

In the U.S., cormorants can only legally be killed with authorization from the USFWS under the Migratory Bird Treaty Act.

This organization has been conducting this movement for a long time for individuals, agencies, and organizations.

Do Double-Crested Cormorants Migrate?

Yes, double-crested cormorants migrate. They usually migrate from the northern Atlantic coast to the south and the southeastern U.S. Others that belong to the western populations migrate to the Pacific coast.

Do Cormorants Eat a lot of Fish?

On a daily basis, cormorants eat about 500 grams of fish which is normal for their diet. However, sometimes, they are unsuccessful at catching fish and leave the fish injured.

Do Cormorants Destroy Trees?

Yes, cormorants do destroy trees. They do irreversible damage to the birds as their guano is extremely acidic and can change the chemistry of the soil. They damage vegetation and damage trees irreversibly.


Every animal, plant, or any living organism that is damaging the environment is also beneficial to the environment. Every living creature plays an important role in balancing the ecosystem.

Just like that, cormorants damage vegetation and property. But they also benefit the ecosystem and are not invasive at all. They do irreversible damage to trees and the soil but are as important to this planet as other animals.

Now that we know so much about cormorants, I hope none of your questions about cormorants being invasive or about understanding their importance have been left unanswered. Make sure to help protect your environment and not kill these birds because there will be consequences because of certain laws.

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