Are Cardinals Aggressive?
Humans & Other Birds, Beware!

The beautiful North-American birds are pretty eye-catching, but they are known for being wild. Read on to learn more about a cardinal’s nature.

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David A. Swanson

June 06, 2021

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What’s This Post About?

These beautiful tiny birds might look a bit petulant on the outside, but that is not the case. Cardinals are lively, chirpy, and great songsters.

The bright red color of male cardinals makes them look a bit hostile on the outside. However, rather than them being aggressive, the fact is that they are more territorial.

The blazing red color of male cardinals calls for everyone’s attention. In contrast, the dull red color of a female cardinal is also quite captivating.

Their extreme territorial behavior is what triggers everyone into thinking that they are aggressive and unpredictable.

Cardinals can be aggressive when it comes to their territory, especially in the breeding season. Male cardinals being hot-headed, will chase away every other bird to the extent that they will showcase aggressive behavior if anyone comes close to the female cardinal or their territory.

an angry cardinal bird

Cardinals Being Aggressive

Cardinals or red birds are often misunderstood as being aggressive for all the wrong reasons.

Cardinals are the most identifiable birds in North America because of their attractive red color.

They become incredibly territorial over the radius they are spread over, especially during breeding and nesting seasons, because they want to protect their established natural territory.

Male cardinals are very quick-tempered. Even if they breed around other species, they will not allow another male cardinal to intrude on their territory.

Even though cardinals are not the largest or wildest birds, they are undoubtedly one of the toughest birds.

Do Cardinals Attack Other Birds?

a cardinal dominating a bird

While defending their territory, male cardinals can attack other male birds if they see them as a threat.

They will charge without a thought. This often leads them to fly straight into glass windows which is nothing but their reflection.

Did You Know?

Unlike many other birds, both male and female cardinals can sing well. Their sweet songs primarily consist of sounds like: - Slurred Whistles - Cheer-cheer whoite - Birdy-bir-dy - Both female and male communicate via ‘pik-chip’ call

How does a Cardinal Behave? Aggressive, Defenders, and Territorial Mates

a cardinal showing aggression

Cardinals, while not being territorial and defensive, are pretty shy and loving birds. However, as mates, a male cardinal will diligently defend its space.

Females also show this fierceness during the mating and breeding season.


Whoever they see as a threat, they will doggedly fight and defend their territory against them.

Monogamous Mating

These birds mate for life.

Once a male cardinal has chosen a female cardinal, the two will start building a nest together. Grasses, small twigs, leaves, and tree barks, cardinals will gather whatever materials help to construct the nest.

a cardinal nest

Some other facts About Nesting!

Eggs 4-5
Number Of Broods 2-3
Nesting Period 14 Days
Incubation Period 10-12 Days

Some cardinal pairs stay together throughout their life span in their nesting zone. Female cardinals lay 2 to 3 eggs, which are incubated for about 12 -13 days.

The male also helps with incubation at times. If one of the mates dies, the surviving cardinal will quickly look for another mate.

What Type Of Relationship Do Cardinals Have With Humans?

Seven states have chosen Northern Cardinal to be their state bird.

a male cardinal

Cardinals do develop a bond with humans that is beyond visiting their yards. The adult cardinals teach their young ones to feel homely around humans and in their yard. They can also recognize differences between human voices.

They also possess the ability to recognize humans and distinguish between the humans that they already know and the humans that might be potential enemies or actual intruders.

This further strengthens their ability to protect their territory if and when needed to survive.

It is said that the cardinals know where to find their food from, and once they find a suitable yard, they usually stick to that.

During summers, they spend a lot of time on the nesting sites despite the presence of humans, unlike other birds, and they make themselves, and their young ones feel comfortable.

However, in winters, they move in large groups from one place to another in search of food.

a female cardinal

However, cardinals are usually seen attacking their reflection. This mostly happens during spring and summer when the female and male cardinals are extra paranoid, making them defend their area from potential enemies.

They are seen attacking their reflection in a mirror or shiny windows, thinking of it as their enemy or an intruder.

They can spend hours fighting off something that is not even real, only because they become incredibly concerned and defensive of their territory around that time, especially male cardinals.

This nature of defensiveness and act of fighting one’s reflection leads to the cardinals hurting themselves in the end.

However, these behaviors are less seen in winters when their aggression lowers down a little, and they become more calm than usual.

Are Cardinals Truly Aggressive?

Cardinals are not aggressive throughout the year except for their mating and nesting period. They are pretty social and self-effacing when the season passes.

However, as a parent bird, both male and female cardinals can be pretty aggressive since these birds are highly protective of their mates and broods.

During the breeding months, male cardinals tend to be a bit more aggressive than usual, trying to show off that they can fight any other cardinal or predator trying to invade their territory.

a cardinal on ground

They get aggressive because they want to protect their nests against predators and male cardinals during the breeding and nesting period.


It is best if you avoid going near to their nest when they are breeding as they will see you as a threat.

Interesting Fact

The record for the longest surviving cardinal is 15 years and 8 months, of a female cardinal found in Pennsylvania.

If you want more insight about cardinal’s territorial behavior, make sure to read my blog on whether cardinals are territorial or not.

Some Interesting Fun Facts About Cardinals

  1. Cardinals are red-colored as they have carotenoids present in their feathers.
  2. The females have light brown to a grayish color.
  3. Both female and male cardinals have shiny orange beaks; it changes color from black to gray to orange as they age.
  4. Cardinals are granivores; they feed on grains.
  5. They are monogamous; that is, they mate for life

What do Cardinals Eat?

Cardinals love all kinds of fruits and berries despite being granivores in nature. Blueberries, blackberries, cherries are some major favorites of these little red birds.

a cardinal feeding

Did You Know?

Cardinals also eat grains like buckwheat, oats, bread crumbs, and millets.

Another great source of food for these birds is suets, and to attract these birds into your backyard, you can hang them in a feeder.

They can be easily lured in by bright, vibrant decorations just like hummingbirds.

Here is a feeder you can explore if you want to get one for your backyard.

Perky-Pet C00322 Red Cardinal Bird Feeder

The circular perch and mesh surface provides a large feeding area

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How Long do Cardinals Live For?

The majority of the Northern Cardinals have been recorded to live for approximately 3 years.

On the contrary, some cardinals have been documented to live longer than 3 years. In rare cases, they may live for up to 8 to 10 years as well.

What Are The Threats To Cardinals?

The most common threat on the land for these birds are dogs and cats.

In addition, loggerhead shrike, grey squirrels, and Cooper’s Hawk are some well-known predators of cardinals as well.

Snakes, blue jays, raccoons are some other threatening predators of cardinals also.

Keep Reading!

Cardinals are no doubt the most exciting and defensive birds to exist. They can be very territorial. However, this behavior does not persist throughout the year.

It’s mostly when they are breeding and nesting that you get to observe their aggressive side.

They are non-migrating birds, so they stay around all year. You get to hear the sweet songs of these birds every day.

The female cardinals sing songs to aware their counter males when they need food or feel threatened.

If you wish to know more about birds that look like cardinals and how to identify them, read this post.

5 Birds That Look Like Cardinals and How to Identify Them

Wondering if those red birds in your backyard are cardinals? Here’s how you can tell the difference between cardinals and other birds.

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By David A. Swanson

Bird Watching USA

My name is David and I'm the the founder of Bird Watching USA! I started Bird Watching with My father-in-law many years ago, and I've become an addict to watching these beautiful creatures. I've learnt so much over about bird watching over the years that I want to share with the world everything I know about them!

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David A. Swanson Picture

David A. Swanson

Bird Watching USA

My name is David and I'm the the founder of Bird Watching USA! I started Bird Watching with My father-in-law many years ago, and I've become an addict to watching these beautiful creatures. I've learnt so much over about bird watching over the years that I want to share with the world everything I know about them!



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