Why Are Swans Aggressive?

As elegant and charming as they are, swans can also be quite aggressive sometimes. But why do they engage in such threatening behavior?

Swans become aggressive primarily during the breeding and nesting season because they try to protect their mates and young. On the other hand, they tend to be more aggressive toward their conspecifics because of competition for food and territory.

Contrary to popular belief, though, swans typically aren’t more aggressive than other waterbirds, especially when it comes to humans. In fact, serious swan attacks on humans are quite rare.

Keep reading if you want to learn more about their behavior!

Why Are Swans Aggressive
An Aggressive Wild Swan

Are Swans Aggressive?

Swans are known to become very aggressive if they feel that anything threatens their chicks, be it another animal or a human being.

Let’s not forget that birds and other animals have an instinct to defend themselves and their young regardless of the threat. Swans will not become aggressive if they do not think there is a reason for self-defense.

Considering how many predators the wilderness is home to, it’s no wonder swans adapted to scaring them away and reacting aggressively to anything that represents the smallest threats.

Are Swans More Aggressive than Other Birds?

Scientists argue that swans aren’t more aggressive than other waterbirds, and this belief is just something we’ve grown up with. All waterbirds are territorial and will protect their nests and young if they’re in danger.

Size may play a significant role in reinforcing this belief. Naturally, one won’t be scared by a small waterbird flapping its wings, whereas an aggressive swan will undoubtedly look very intimidating and scary!

On the other hand, not all waterbirds become aggressive toward each other if food is scarce, for example, and some swans are known to attack others because of competition.

Additionally, it has been proved that male waterbirds are more aggressive than females. The age may also influence the degree of aggressiveness, as adults are known to be more hostile toward intruders than juveniles.

Why Are Swans Aggressive?

Swans are usually the most aggressive during the breeding and nesting seasons, meaning between April and June. Both male and female swans tend to become highly aggressive and territorial while protecting their mates, nests, and babies.

They do not only chase away and attack humans, dogs, and other animals they perceive as predators. They are also known to aggressively drive other waterfowl out of their nesting areas. This is valid for various swan species, including mute swans and black swans.

If you think that’s frightening, wait until you hear the results of a study on aggressive behavioral interactions between swans! Scientists discovered that swans tend to be even more aggressive with other swans than smaller waterbirds.

This is linked to resource use and high potential for competition. As such, not only humans and other animals are in danger of being attacked by swans. They’ll fight each other too!

Nevertheless, a swan does not hunt people or pets down to attack them. Unless you’re too close to their nesting grounds and intrude on their territories, swans won’t see any reason to attack anyone, so it’s recommended to keep your distance. We know that swans are quite elegant, and their beauty may tempt us to get closer, but they’re just as elegant from afar!

In fact, many swan species, like the Tundra swan, are known to be quite gregarious outside the breeding season, which further proves that the pronounced aggression is driven by the instinct of ensuring the continuation of their species. 

How Do You Know If a Swan Becomes Aggressive?

If you live in an area where swans breed, you undoubtedly need to be acquainted with a few signs of swan aggression, as well as ways to prevent one and, if not possible, how to deal with it.

If a swan shows any of the following signs, you might be in danger of being attacked:

  • The swan may loudly hiss, trying to scare the “predator” away.
  • The swan may aggressively flap its wings and/or spread its wings wide.
  • The swan may stretch its neck upward.

If you notice any of the signs mentioned above, you should keep your eyes on the swan and slowly back away without turning your back to the swan.

It’s essential to remain calm and avoid doing anything that would equal aggressiveness in a swan’s eyes – do not shout, run away, or make sudden movements. You may try to open your arms slowly as wide as possible to appear more intimidating.

How Do Swans Attack Other Birds?

If they feel threatened by other birds or consider them intruders, swans won’t back down from chasing them away or killing them.

Some will chase other waterbirds away by hissing or busking accompanied by a fast swimming approach. Their necks will be curved back and the wings half raised.

Mute swans, for example, will use their bony wing spurs to strike the threat, while the bill will be used to deliver painful bites.

If the threat is a small waterbird, the swan will grab it with its bill and drag it far from the nest.

If the situation becomes extreme and the swan feels the need to get rid of the intruder, it will drown it by either climbing onto it or pecking the back of the bird’s head to force it to stay underwater.

Can a Swan Break Your Arm with Its Neck?

Although swans are quite strong, their necks aren’t strong enough to break the arm or leg of an adult human being. At least, this has never happened in real life.

A swan weighs only approximately 11 kilograms (24 pounds) and has hollow bones, so it does not stand a chance of breaking a human bone.

If anything, humans may break their bones by accident while trying to get away from an attacking swan. On the other hand, a swan attack may result in bruises from wing strikes or bites.

Has a Swan Ever Killed a Human?

There’s only one official report of a swan killing a human.

Supposedly, Anthony Hensley, a 37-year-old man, was tending to the birds in a pond just outside Chicago when a swan knocked him out of his kayak and kept attacking him until he drowned. Anthony tried to swim to shore, but the swan did not let it reach it.

Ornithologists suspect that the swan reacted aggressively because Anthony Hensley was probably too close to the swan’s nest.

However, as mentioned, this is an isolated case, and such aggressive attacks are very rare.


Why is a swan hissing at me?

Swans will typically hiss when approached, as they consider anyone approaching them a threat. As such, if you’re not trained on how to safely approach a swan, we recommend backing away if it starts hissing.

Are swans more aggressive than geese?

Both swans and geese tend to become aggressive during the breeding and nesting season. Studies show that all waterbirds are equally aggressive..

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