Our nesting Great Tits

Typically for this time of year we have been fortunate enough to have a pair of Great Tits take up residence in one of our nesting boxes; attached to the side of the St Nicholas Barn. Great Tits; like Blue Tits, Robins, Wrens and Dunnocks all take readily to artificial nesting boxes and are relatively easy to study. Having our ‘Nature-Watch’ Cameras inside the box has meant that we can stream live images of the birds as they nest, incubate, hatch and fledge their young.

Investigating the nest site

Investigating the nest site

The pair began investigating the box in the middle of March and it wasn’t long before the female bird started to use the box as a favoured roosting site. From that moment on, I have been keeping a close eye on developments!

The male bird was noticed roosting in the box at the far end of the barn, and during the day would be seen with the female and helping out with the nest-building which had started at the beginning of April. Great Tits construct their nests from dry hay and grasses that they flatten into a sponge-like mass on the floor of the box; in a natural setting this would be the floor of a cavity in a tree or in the fork of a large shrub. This layer will form a base which absorbs fluids from the hatching eggs and later any liquid excretions from the chicks themselves; much like a nappy on a newborn!

Building the base by flattening down the dried grasses

Building the base by flattening down the dried grasses

As the month has progressed, I have watched as the nest has been completed, with the female continuing to roost in the box and the male nearby; preventing any other Tits from occupying the neighbouring box! Occasionally he would be seen entering the nest box with materials to help in the final stages of construction, or with a morsel of food for the weary female; a good sign of the bond between the pair. Although it is not uncommon for a male Great Tit to have more than one female to ‘visit’ during the mating season, it does seem that our male is doing right by his lady!

Final stages... Great Tits use finer materials like feathers and fur to line the top of the nest which helps to insulate the eggs and chicks.

Final stages… Great Tits use finer materials like feathers and fur to line the top of the nest which helps to insulate the eggs and chicks.

The nest-building is not fully completed until after laying begins, but a sure sign that this is close is when the female begins to draw up insulation such as mosses, feathers and fur into a cup shape around her, which she flattens and moulds into shape with intricate movements of her body and beak. Sure enough, I believe that she began laying around the 11th of April. She covers the first clutch of eggs with more moss and feathers as she will lay a complete clutch of 7-9 eggs over the course of a few days and will be in and out of the nest looking for a good supply of food for when the chicks hatch.

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The male bringing food back to the nest for the female. This precedes the feeding of the chicks which will be shared by both parents. Initially however the male will bring food that the female will break up or regurgitate to the chicks.

Our female spent much of this time in the box since the male was regularly bringing in food for her. Great Tits, like all small woodland/farmland birds will only attempt breeding when they know that they have a good supply of the insects and particularly caterpillar grubs that will form the basis of their own and their chick’s diet during the coming weeks. At Gressenhall we are not short of wild and woody areas where these insects thrive so our female could afford to spend much of her time with the eggs. In all, she has laid 9 eggs; a great clutch!

9 eggs in all. Notice the 'cup' construction of fine mosses, feathers and fur.

9 eggs in all. Notice the ‘cup’ construction of fine mosses, feathers and fur.

Both birds took turns in incubating the eggs and this period lasts for around two weeks. It is generally believed that the female incubates alone, but I have observed both parents incubating; the male distinguishable by his prominent dark black chest stripe. They will rely on one another for food whilst incubating; swapping duties many times during the day.

Hatching chicks

Hatching chicks.

The first of our chicks hatched late on 25th April and into the early hours of 26th April. The female dutifully eats the egg shells and sits on the newborns to keep them warm as they are born without any feathers or down. In the morning, the male returns and quickly takes over the babysitting; with the female free to stretch her wings and go out foraging.  The final hatchings took place on this Sunday last, and I am busy trying to make out if we have the full 9 birds; I haven’t seen any dead ones outside on the ground below the box, nor have I observed the adults disposing of any. All good signs that for now at least, we have a full complement.

Removing a faecal sac.

Removing a fecal sac.

Now that all the babies are hatched, it is the female who is more or less permanently in the nest box. The male brings food for both mother and babies, with the mother regurgitating smaller pieces of food for the chicks. She will occasionally be seen leaving the nest to forage for her own food and bring in more for the chicks, but from what I have observed, the male is very busy at the moment; backwards and forwards many times during daylight hours. And he is still roosting in the neighbouring box!

Feeding the chicks

Feeding the chicks

These common and abundant birds offer us a glimpse into their fascinating lives when they nest in boxes. We are lucky at Gressenhall to be able to peek in with the cameras and get an even closer look. I will be posting more pictures of the chicks as they develop and eventually fledge in about a month’s time. Gressenhall’s resident Barn Owl pair have also been busy this Spring and I will have some news on them to follow shortly!

 

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