There are lots of eggs about at the moment. Lots of chocolate eggs, painted eggs and those random bits of eggshells you find in your garden or on the street.
What are they doing there?
Why would a bird leave an eggshell lying around? Empty shells at the nest could attract the attention of predators, so birds will often remove them and dump them somewhere else.
On the other hand, the breeding season is hard work for birds, both males and females. There's a lot of nest-building to be done, and then all that flying to and fro, keeping a hungry brood of chicks fed. The female also has to lay eggs - a big investment of energy and nutrients.
To recoup some of that investment, the female bird sometimes eats the eggshells once the chicks have hatched. She might go on to lay another clutch, so it's a sensible way to replenish her reserves of calcium.
Who lives in an egg like this?
Some of the most common eggshells to be found are from birds like blackbirds, starlings and collared doves.
Blackbirds and starlings produce eggs that measure roughly 3 x 2 cm. Both are pale blue, but blackbird eggs are speckled with brown. Perhaps surprisingly, collared dove eggs are not much bigger (3 x 2.5 cm), but they are white. Watch out for these on a lawn near you!
The long wait
Incubating the eggs before they hatch appears to be rather a dull job, from the outside (have a look at our bird of prey webcams to see if you can spot 'EJ' the osprey or the female peregrine at Chichester having a snooze during the long wait).
To help keep the eggs (and later the chicks) warm, many female birds develop what is known as a 'brood patch'. Some of the feathers on her belly drop out, leaving a patch of naked skin. The skin itself changes, getting thicker and wrinklier with enlarged veins! It sounds a bit strange, but it's a more efficient way of getting body heat onto the eggs.
Birds don't have teeth... do they?
Birds have a tough start to their lives. They have to break their way out of the eggshell that's protected them while they develop. Such a tiny creature has to use a special tool to achieve this feat, so it comes equipped with an 'egg tooth' - effectively a tiny chisel on the upper part of the beak.
In the picture on the left you can see a black-headed gull chick chipping its way out of the egg - the beak is visible, with its egg tooth. You can also see the pattern of tiny cracks in the shell that the chick has made on its way out.
All these amazing things are going on near you as you read this... down your street, in your garden, in a nestbox or tree, or even in your roof. Let's hope that the weather's kind and our birds have a successful breeding season this year.
Hi. Thanks for all your comments! I hope Easter brought you eggs, one way or another... To answer your questions...
mini gran: yes, a goose egg sounds like a likely suspect. I'd guess a predator (fox or crow) will have deposited it there.
Nilubi: It's female robins that perform the incubation duties. But males and females are identical, to our eyes at least, so I suspect that's what you're seeing. Fingers crossed!
Can't believe how so many different species visit my garden so far i have seen - Tits blue,great,long tailed,
geenfinch,goldfinch,nightingale,robin,dunnock, mistle and song thrush, blackbirds - magpies,doves and wood pidgeons try to spoil it all the time lets hope the little ones do well
There is a Robin nesting in my window box between two little lavender bush!! and i was so excited to find it has three eggs!! I am now spying through my blinds.... I really hope they will all hatch safely. It seems only the dad sitting on it though, is that a Robin's way?
I recently found a large white egg abandoned in the middle of a garden centre car park ! It's 10 cm X7 cm and I think belongs to some kind of goose, as there's a flock nearby.
Have fun out there!
Sue Atkin
The Blue-tits in our nest-box have 8 eggs up to today. We have a camera in there; it is fascinating watching mum and dad at this wonderful time of year. Yes, birds are such a joy.