Blue Tit blog

The months of May and June are by far the busiest times for Blue Tits - with eggs to incubate and young getting bigger by the day, the demand for food is constant. These two months mark the end of their breeding season, but Blue Tits start to think about breeding as early as February.

February

Looking for the ideal home

Now is the time to find a safe, warm nesting site to rear your chicks. Location is important - there must be a clear flight path to the entrance hole and it must be relatively inaccessible to predators. Finding the perfect partner is also a top priority at this time.

March

Time to fatten up

Birds need to be in prime condition at the start of the breeding season - peanuts, black sunflower seeds and suet provide a valuable source of nutrients. The energy this extra food provides will be used to produce the eggs and keep parents in good condition so that they are able to provide enough food for their chicks.

April

Interior design

The female Blue Tit builds the nest all by herself with little or no help from the male. Moss will be taken from garden lawns and formed into a cup. You will know that the nest is complete and ready for laying 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.

Early May

An egg a day

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 - she may l ay up to 16 eggs, but the majority of clutches contain 8-12.

Mid May

Staying put

The female plucks away her feathers on her abdomen to create a bare patch (called a ‘brood patch’) to incubate the eggs. She will start to incubate the clutch the 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

Time to hatch

The chicks hatch naked and blind and are most vulnerable at this time. They need constant warmth, and the female will frequently sit on them. Finding enough food can prove difficult if the weather is cold and wet.

End May

Growing appetites

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 adults need to find as many as 1000 caterpillars a day for a brood of 10! By now the chicks’ feathers are more developed and they are starting to look more like they might be capable of flying.

Early June

Take off

When the chicks are ready to fledge, the parents will call them 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, and to the nearest available perch.

June and July

Hanging out with mum and dad

Fledglings will stay with (and be fed by) their parents for a few weeks after they fledge. 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. They may well take advantage of peanuts and sunflower seeds provided in gardens to build up their strength.


Great Tits breed slightly earlier than Blue Tits, on average by about a week, but the amount of time they spend incubating the eggs and rearing the chicks is very similar. Multiple brooded species such as Robin and Blackbird may be starting to lay eggs very soon, so the best time to start checking your box is now - you never know what you may find.

Monitor the success of the birds in your nest boxes by taking part in the Nest Box Challenge. Register to take part in the survey and submit the details of your nesting birds online.

Take part in Nest Box Challenge