A Blue Tit diary

Hazel McCambridge walks through the diary of an average Blue Tit during the breeding season.

Blue Tit. Edmund Fellowes

Hazel McCambridge

Scheme Administrator

Hazel is the lead organiser of Nest Box Challenge and Norfolk Bat Survey. She also provides clerical support to the Ringing and Nest Record Scheme, working on data collection, volunteer communication and licensing.


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May and June are busy times for Blue Tits. With eggs to incubate and young chicks getting bigger by the day, the demand for food is constant. Whilst these months mark the end of their breeding season, Blue Tits start trying to find a partner and a suitable nest site as early as February.

February

Blue Tits start searching for a safe, warm site to start building their nest. The location is important as they require a clear flight path to the nest's entrance hole and the site must be relatively inaccessible to predators. Finding the perfect partner is also a top priority at this time.

Blue Tit. John Flowerday
February - looking for the ideal home. John Flowerday
Blue Tit. Paul Newton
March - time to fatten up. Paul Newton 

March

Birds need to be in prime condition at the start of the breeding season. Placing bird food in the garden, particularly suet, peanuts and black sunflower seeds, provides a valuable source of nutrients and energy which can be used by females to produce eggs and keeps both parents in good condition so that they are able to supply enough food for their chicks.

The female Blue Tit builds the nest alone with little or no help from the male.  

April

The female Blue Tit builds the nest alone with little or no help from the male. She takes moss will from garden lawns and forms it into a cup. The nest is complete when it is lined with soft feathers, fur or wool. Blue Tits can build a nest in a few days, but generally it takes them between one and two weeks.

Blue Tit. Edmund Fellowes
April - collecting hair to line a nest. Edmund Fellowes
Blue Tit eggs. Moss Taylor
Early May - and egg a day. Moss Taylor 
This is an exhausting time for the female. She lays one egg a day...up to 16 eggs!  

Early May

This is an exhausting time for the female. She lays one egg a day, usually first thing in the morning. Blue Tits have one of the largest clutch sizes of all birds - up to 16 eggs! However, the majority of clutches contain 8-12 eggs.

Mid-May

The female plucks feathers from her abdomen to create a bare patch with a good supply of blood vessels (called a ‘brood patch’) which helps her to keep the eggs warm as she incubates them. She starts incubating the clutch a day before it is complete and will sit on the eggs for about two weeks until they are ready to hatch. During this time, if she made a good choice of mate, the male will bring her some food, but she will still need to leave the box regularly during the day to feed.

Late May

The chicks hatch naked and blind; as they are so vulnerable at this time the female will frequently sit on them to keep them warm. If the weather is particularly cold and wet finding enough caterpillars to help them grow can prove difficult. Trends show that on average spring is arriving earlier due to a changing climate and in turn trees' leaves open earlier, providing food for caterpillars earlier, so that they in turn peak in abundance earlier in the year than previously. Blue Tits have started to breed earlier too, but their shift has not kept pace with that of the peak abundance of caterpillars. BTO research is investigating the implications of this 'phenological mismatch' for Blue Tits and other species.

Blue Tit. Mark C Mainwaring
Late May - Blue Tit nest box with recently hatched young.
Blue Tit nest with well-grown chicks. Simon Thurgood.
End of May - well grown chicks with growing appetites. Simon Thurgood 
Each chick can eat 100 caterpillars a day.  

End of May

Feeding chicks takes its toll on the parents as they flit in and out of the nest box with juicy fat caterpillars. Each chick can eat 100 caterpillars a day, so to feed a brood of ten, adults need to find as many as 1,000 caterpillars a day. Adults also need to remove the chicks faecal sacks to keep the nest clean. By now the chicks’ feathers are well-developed and they are starting to look like they might be capable of flying.

Early June

When the chicks are ready to fledge, the parents will call from outside the box, urging them to come out. One by one each chick will poke its head out and make their first tentative flight (usually badly) to the nearest available perch. Blue Tit chicks typically fledge when they are 18-21 days old.

June and July

Fledglings stay with their parents who continue to feed them for a few weeks after they have fledged. This is a dangerous time for young birds. They need to learn how to find food and avoid predators quickly if they are going to survive. If available, they may take advantage of peanuts and sunflower seeds provided in gardens to build up their strength.

Blue Tit. Paul Newton
Early June - Blue Tit pullus looking out of nestbox. Paul Newton
Great Tit. Sarah Kelman
Great Tits breed slightly earlier than Blue Tits. Sarah Kelman 
Providing for wildlife in your garden. Mike Toms
Get the whole story by monitoring the birds in your garden. Mike Toms 

Rest of the year

Blue Tits tend to be quite sedentary birds, staying close to where they hatched as chicks, but some individuals do migrate, so the Blue Tits you see in winter might have hatched or bred elsewhere in northern Europe. Winter is a tough time for many species and Blue Tits are no exception. Blue Tits in urban settings rely heavily on food provided in people's gardens at this time, and may also use nest boxes in winter for shelter, especially during the night. Almost two thirds of young Blue Tits will not survive their first year of life, but those that do usually start to breed the spring after they hatched. Blue Tits typically live for three years, but the maximum age recorded from bird ringing is 10 years, 3 months and 10 days.

Keep an eye out for other garden nesters

Great Tits breed slightly (approximately a week) earlier than Blue Tits, but the amount of time they spend incubating eggs and rearing chicks is very similar.  Species that have multiple broods such as Robins and Blackbirds, usually lay their first clutch in March. Early spring onwards is a good time to start checking your box - you never know what you may find.

Get the whole story by monitoring the birds in your garden

This is one chapter in the dramatic and fascinating story of the wildlife in your garden. Gain a richer understanding by participating in one of our citizen science schemes, which contribute to conservation data.

Complete a 20 minute count of the birds in your garden every week with Garden BirdWatch, and find out how things change throughout the year supported by our passionate GBW team and community.

If you would like to monitor the nests in your garden and add to the national picture then try Nest Box Challenge. Simply register the nest boxes or nests in your garden or local area and record what's inside at regular intervals during the breeding season.

Take part in Garden BirdWatch

Monitor the Blue Tits in your garden all year round by volunteering for Garden BirdWatch.

Find out more


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