Over the course of many years, a tidy collection of bird eggs has made its way across the world. The collection’s final resting place just so happens to be here at Te Papa, where Natural History intern Isabella Milner has steadily worked through cataloguing it and packing the eggs away into their forever homes. Here she describes how eggs are identified despite having very little information to go on.

All we know about this collection is from a note written by Charles McCann, vertebrate zoologist of the Dominion Museum, Te Papa’s predecessor. This note states that the collection was given to a former director of the museum, John Yaldwyn, in 1955, although not much is known about where it came from nor about the collector themselves.

But the eggs inside this neat and sturdy box tell of a journey around England, Australia, and here in New Zealand, judging by the species the eggs belong to, and by extra information provided by the anonymous collector.

Typically, bird eggs are portrayed as plain white or brown and round with one pointier end. This is partly true, considering these are the eggs you’re more likely to see in aisle six of your local supermarket. Even within the variety of species in this collection, many of them do appear similar at first glance, making identification rather difficult.

But look a bit more closely and you’ll notice the incredible variability in patterns, colours and shapes across all taxa. Not all of them are plain and round. Some are tinged with blue and green and brown. Others have speckles of red and splotches of grey, like tiny works of avian art.

Take the yellowhammer, for example, a common introduced species in New Zealand.

It’s fairly obvious why it was named so, but the bright conspicuous colour of its plumage isn’t reflected in its eggs. Instead, they are painted with scribbles of a deep purple, the complete opposite of yellow on the colour wheel.

The nightjar is much more subtle in its art form, with whitish eggs covered in faint blue and brown blotches of many hues. Patterns like these allow them to blend with their surroundings, hidden in plain sight from hungry predators.

In this case, the parent nightjars are much more camouflaged than their eggs, with plumage that is virtually impossible to spot where they tend to nest.

A good egg

Because of the many similarities and differences between eggs, some are easier to identify than others. Information written onto an accompanying note or delicately scribed onto the egg itself is the most helpful. The larger the egg is, the more surface area to write on.

One of the largest in the collection belongs to the little penguin – a common inhabitant along New Zealand shores – and it has a bounty of valuable information across its surface. Because of this, we know the species and that it was collected in the Bay of Plenty.

Scrambling for information

Others are more secretive with their details, divulging only a common name and maybe a location if I’m lucky. Sometimes that is enough to add it to the database, but in a lot of these cases, further investigation is needed.

A bit of digging around – comparing with other eggs, searching pictures in bird books and matching habitat ranges – has allowed me to identify several unlabelled eggs.

The majority remain in remarkable condition despite their long journey across the world. Surprisingly, a bit of padding in a wooden box was enough to preserve even the most delicate of shells. I like to think of it as a representation of how fragile, yet resilient nature can be.

Despite the constant – but careful – prodding of human fingers (including my own), they continue to keep their shape, while a well-placed peck from a beak is enough to shatter them.

They will continue to be protected in their new home, snuggled up in padded boxes and stacked neatly into filing cabinets, contributing to a record of the precious biodiversity in New Zealand and beyond.