Arctic Tern Vs Black Headed Gull: Key Differences Explained

Arctic Tern Vs Black Headed Gull: Key Differences Explained

At first glance, it can be incredibly difficult to tell the difference between a black headed gull and an Arctic tern. They both have grey bodies, a black head and red feet and legs.

However, there are enough differences to allow the correct identification of each bird. In this article, we’ll be looking at those differences so that you can correctly differentiate between these two fascinating and entertaining birds.

Keep reading to find out more.

Key Takeaways

  • Arctic terns are more streamlined and have a sleaker build than black headed gulls
  • Black headed gulls are heavier and chunkier looking than Arctic terns
  • Black headed gulls have a thicker bill which is more hooked at the end
  • Black headed gulls are confident around humans unlike the more reclusive Arctic terns
  • Black headed gulls have black tipped wings with white flashes along the edges
  • Arctic terns have silver/grey wing tips

What Is The Difference Between An Arctic Tern And A Black Headed Gull?

There are several differences between Arctic terns and black headed gulls which include;

Visual Differences

Arctic terns are sleeker and more streamlined than black headed gulls. They also have more pointed bills and an overall more delicate shape.

Black headed gulls look heavier with a chunkier body as well as a thicker bill which is hooked at the end. Black headed gulls also have longer legs than Arctic terns and you’re more likely to see black headed gulls around humans.

Wing Markings

Female Arctic Tern

Another way to differentiate between these two birds is by looking closely at their wings. Black headed gulls have black tipped wings and white flashes along the edge of the wings. While Arctic terns have silver/grey wingtips.

Arctic terns tend to stay away from humans and build their nests in areas where humans don’t often frequent. Gulls are much more likely to build their nests and hang around heavily populated areas most likely in order to procure some human food.

Another surefire way to differentiate between these two bird species is in the way they hunt for food. The Arctic tern will often be seen flying over water typically with its head pointing towards the water looking for its prey.

It will then dive straight down from anywhere between  6 to 15 metres to take a fish from the water. Black headed gulls on the other hand are much more likely to simply swoop down to get a fish or grab the fish as it is paddling on top of the water.

If the bird in question is swimming much like a duck, then it’s definitely a black headed gull. This is because Arctic terns (or any terns for that matter) don’t have webbed feet like gulls do.

You might also find black headed gulls scavenging on land for anything edible as they are omnivores. Whereas Arctic terns tend to only eat small fish and insects which they pluck from the air or from the surface of the water.

Differences In Habitat

Black headed gulls tend to nest in colonies ranging in size from a few to tens of thousands. They can be found in any wet habitat including duck ponds, farmer’s fields, wetlands and coastal areas. But they will also nest in dry areas as long as there is water nearby.

Arctic terns prefer open, treeless areas or small islands and barrier beaches. They always choose nesting sites close to a source of water. Either a stream, pond, lake, estuary or the open sea. This makes it easy to find food for themselves and their chicks.

Nests & Eggs

Both of these birds make scrape nests which are just slight depressions in the ground and both parents contribute to the nest building process. 

Black headed gulls will either make their nest directly on the ground or on a pile of dead plant material. The mother will lay anywhere between 1 to 4 eggs which are green in colour with brown spots or freckles.

The chicks hatch after an incubation period of around 22 to 26 days. Black headed gull chicks are precocial which means they hatch with their eyes open and covered in down. They can typically leave the nest after around 48 hours but spend a further 30 to 35 days with their parents before fledging.

Both parents feed the chicks and teach them how to find food for themselves.

Arctic terns make their nests directly on the ground in a shallow depression which is created by both parents scraping the ground away. This is often lined with plant material from the local area.

The mother will lay anywhere between 1 to 3 eggs which are an olive or buff colour with dark brown spots or freckles. The eggs are incubated for around 21 to 24 days and the chicks are hatched with their eyes open and are covered in down.

They can walk as soon as they are hatched but don’t leave the nest for around 21 to 28 days. Both parents feed the chicks who are also taught how to find food before they fledge at around day 28 or so.

Bird Calls

The call of the Arctic tern is a sharp piercing sound which can often be heard around their nesting sites. They also make a series of high pitched cries when communicating with their mates and to deter intruders.

The call of the black headed gull is often compared to the sound of laughter. The sound is a loud “kree-ar” and is used when the gulls are in their nesting colonies and as a form of social structuring.

Size & Weight

Male Black-Headed Gull

Although both of these birds are a similar length, they have different wingspans and significantly different weights.

Black headed gulls are around 33 to 37 cm in length with a wingspan of between 100 to 110 cm.

Arctic terns are around 32 to 35 cm in length with a wingspan of around 75 to 86 cm.

The main difference is in their weights with Arctic terns weighing around 95 to 125 g while black headed gulls weigh around 200 to 400 g. 

As you can see black headed gulls weigh around twice or even 4 times as much as Arctic terns and yet there’s not that much of a difference in the length of these two birds.

When Can You See These Birds In The UK?

Arctic terns can only be seen in the UK between the months of April to September. The rest of the year they are to be found either in the Arctic or Antarctic regions.

Black headed gulls can be seen in the UK throughout the year as they are permanent residents. In some areas their numbers swell during the winter months as more black headed gulls arrive from mainland Europe. 

SEE ALSO: Arctic Tern Life Cycle: Nest Building To Fledging (and everything in between)

Frequently Asked Questions

How do you tell the difference between an Arctic tern and a black headed gull?

Arctic terns are smaller and have a more slender streamlined body than black headed gulls. Arctic terns are also more elegant fliers and are often seen hovering over the water before diving in to catch their prey.

What bird looks like a seagull but has a black head?

If you see a seagull that has a black head, it is most likely to be a black headed gull. These birds are to be found all around the UK where they are permanent residents.

What bird is similar to a black-headed gull?

The brown headed gull is similar to a black headed gull. However, the brown headed gull has a slightly heavier bill, a light iris around the eye and brighter red legs and bill.

Leave a Reply

Your email address will not be published. Required fields are marked *