Roseate Tern Life Cycle: Nest Building To Fledging (and everything in between)

Roseate Terns are named after their pink flushed breast and are one of the rarest seabirds to be seen in the UK. They are similar in appearance to Arctic Terns and Common Terns but can be distinguished by their shorter wings, longer bill and two long tail feathers which are evident during the breeding season.

During summer, Roseate Terns have a whitish-grey back and wings, white underparts tinged with pink and a black cap. If seen within a flock of mixed Terns, the Roseate Tern will be the one that appears to be glowing white.

In this article we’ll be taking a close look at the early life cycle of the Roseate Tern from nest building, through egg laying and on to fledging. Keep reading to find out more.

How Long Does A Roseate Tern Live?

Roseate Terns are Red listed on the UK Birds of Conservation Concern due to the decrease in population size. The average lifespan of a Roseate Tern is around 8 years. They reach sexual maturity at around the age of 2.

According to ring data, the maximum age attained by a Roseate Tern is nearly 24 years (23 years, 10 months and 8 days).

How Fast Can A Roseate Tern Fly?

Roseate Terns can reach speeds of up to 40 mph (64 km/h) which is around 18 metres per second. When hunting for food, the Roseate Tern can plunge into water and dive under the surface and can fly underwater for short distances chasing fish.

Are Roseate Terns Aggressive?

Whilst not as aggressive as other Tern species, the Roseate Tern can display aggressive tendencies towards other males if they venture too close to their nesting sites. If they perceive a threat to the nesting colony, Roseate Terns will dive bomb the intruders whilst calling loudly.

However, this action is typically only a protective measure and not an indicator of any inherent aggression. Having said that, they can be termed as aggressive in the way they relentlessly chase fish even flying underwater to catch their prey.

They can sometimes steal fish from other seabirds in a behaviour known as “kleptoparasitism”.

What Is A Roseate Tern’s Habitat?

Roseate Terns are marine birds and spend most of their lives at sea. Only coming ashore for breeding purposes. They nest on salt water coastlines and sometimes around gravel pits, lakes and reservoirs inland.

However, their typical nesting site is on low lying rocky islands where they will breed in colonies.

How Long Does It Take For A Roseate Tern To Build A Nest?

It can take a Roseate Tern anywhere between 1 to 5 days to build a nest. The actual building part takes less than 1 day but it takes far longer in many cases to select the correct nesting site.

The nest itself is a simple scrape nest which is constructed in sand, gravel or vegetation. Once scraped into shape, the nest will be lined with grass, shells and other materials found along the coastline.

Nesting sites are often found close to the nests of Common and Arctic Terns. The Roseate Terns rely on these other Tern species to defend the nesting area from intruders.

Eggs

Once the nest site has been selected and the nest is completed to the satisfaction of the female, she will lay her eggs.

When Do Roseate Terns Lay Eggs?

Roseate Terns typically lay their eggs between mid May and mid June. This is usually around 2 to 3 weeks after they start visiting the nesting colony. They only lay one clutch per season and don’t typically start to breed until they are 2 or 3 years old.

How Many Eggs Does A Roseate Tern Lay?

A typical clutch of Roseate Tern eggs consists of 1 or 2 eggs. This low number of eggs ensures that the parents can afford enough time and energy to successfully raise their young.

What Do Roseate Tern Eggs Look Like?

It is often difficult to differentiate between the eggs of Common Terns and Roseate Terns. This is because both species lay eggs that look similar. Being various shades of brown with darker streaks and spots.

However, Roseate Tern eggs tend to be more uniformly marked with less blotches and smaller spots. They are roughly 43 x 30 mm in size and weigh around 20 grams.

How Long Do Roseate Tern Eggs Take To Hatch?

Both parents take part in incubating the eggs although the female does most. The eggs are incubated for around 23 to 24 days and incubation starts as soon as the last egg is laid.

Chicks

After the eggs hatch we move on to the next stage in the reproductive process, the chicks.

How Many Chicks Does A Roseate Tern Have?

Roseate Terns typically raise one chick per year. Although some more experienced parents are able to successfully raise 2 chicks, in many cases only 1 chick will survive. This is because the 2nd chick will often die from starvation because the parents cannot provide enough food for both chicks.

They will generally need to fly long distances to find food and as the developing chicks are so demanding, they can usually only provide enough food for 1 chick.

When Do Roseate Tern Chicks Open Their Eyes?

Roseate Tern chicks can usually open their eyes a few hours after hatching and are able to move around the nest and take food. One chick will usually become more dominant and will often cause the other chick to starve for lack of food.

The dominant chick will even steal food from the mouth of its sibling.

When Do Roseate Tern Chicks Fledge?

Roseate Tern chicks typically leave the nest a few days after hatching but cannot fly until they reach an age of around 22 to 30 days. During this time the chicks develop and grow until they’re strong enough to take their first flight or fledge.

Even after fledging, Roseate Tern chicks remain with their parents for anywhere up to 8 weeks. During this time they learn where to find food and how to fend for themselves.

SEE ALSO: Grey Heron Life Cycle: Nest Building To Fledging (and everything in between)

Frequently Asked Questions