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Nests, Eggs and Life Cycles

Did you know that there is more to a bird’s nest than just sticks? Let’s jump into the world of nest building and egg laying to find out more about the life cycle of a bird.


Birds build nests so they have a safe place to lay their eggs. Nests can be different shapes, sizes and made from lots of different things. Willie wagtails like to make small nests using grasses and spiderwebs. Albatrosses like to make nests on the ground using mud and bits of plants. Sea eagles build messy looking nests using big sticks, high up in a tree. 

A Dusky Moorhen nest in a pond at Centennial Park

Birds use lots of different things to build their nests. Have a look at the nests below. Can you work out what sorts of things have been used to make them? 

Bird eggs come in lots of different sizes and colours. They don’t come in many different shapes because lots of shapes have corners and no bird wants to squeeze out sharp corners! Little birds lay little eggs and big birds lay bigger eggs. 

Have a look at these bird eggs. Can you match them to the birds in the bird guide? Why do you think there is a 5c coin in the photos? 

Parts of an egg! 

What happens after a bird has laid an egg? Let’s have a look at the life cycle of a bird, starring Steve the Kookaburra. 

Watch real life baby Kookaburras growing from hatchlings to nestlings. Warning: they are not cute at all!


Not all birds have this life cycle. Watch this video about Emus by ABC Education. Can you work out which part is missing from an Emu’s life cycle?  

Check out some of the cute baby birds we see here at the Royal Botanic Garden Sydney and Centennial Park. 

There are lots of animals that will eat eggs and baby birds if they see them. Birds need safe places where they can build their nests to protect them from predators. Lots of birds, including Steve and his family, use holes in trees called hollows. Hollows are only found in old trees and take over 100 years to become big enough for animals to nest in. They are mostly found in Eucalyptus trees like the ones below. 

When people cut down all the old trees to build something new, they are taking away all the good nesting spots. Even if they plant young trees to make up for it, the birds will have to wait hundreds of years until those trees get hollows.  

If there are no hollows in an area, we can help birds and other animals by putting up nest boxes that act like fake hollows. This will help make safe places for birds to nest and continue their life cycle. 

We also need to keep big, old trees around. Do you have any old trees with hollows near your house or school? Here at the Royal Botanic Garden Sydney, we are part of the community project ‘Hollows as Homes’ and you can be too! ‘Hollows as Homes’ wants to find out where there are hollows, what animals use them and just how important they are. 

If you want to find out more, check out the information on our website.

Activities - Nests, Eggs and Life Cycles

1. Complete the nest challenge

Try to build a nest like a bird, using only your beak (some kitchen tongs) and feet.  
a) Was it hard? What were some problems you had?  
b) Write a comic about what your life would be like if you had wings instead of hands. How would you get dressed? eat? go to school? 

2. Drawing birds

Draw life sized birds and their eggs on your driveway!  To do this you will need a ruler or measuring tape and chalk. 

Draw Australia’s tallest bird: 

Emu = 1.80m long (remember there are 100cm in 1m) 
Its egg = 13cm long, 9cm wide 

Draw Australia’s smallest bird: 
Weebill = 8cm long 
Its egg = 15mm long, 11mm wide (remember there are 10mm in 1cm) 

Label your drawings so people walking past can learn too. You might like to research the world’s tallest bird and add to your drawings. 

3. Design a nest box

Steve the Kookaburra needs a nest box. Design it, making sure it has the following requirements.

  • Will fit a 42cm tall kookaburra and have room for chicks. Show your measurements. 
  • Has soft things to keep the chicks warm. 
  • Includes a door that is 20cm wide and 15cm tall. 
  • Has a way for rain to run off the roof. 
  • Is to be between 5 and 10m high in a tree.

Draw the tree and where you would put it. How will you stop goannas, cats and rats from trying to climb the tree? Will you camouflage your nest box? How? 

Make sure you label your design to help explain your choices.