Learn about the History of Biodiversity in Aotearoa
The value of conservation is better understood by an appreciation of lost biodiversity. New Zealand's greatest biological loss is 42 percent of its' terrestrial birds since human settlement 700 years ago. The 57 extinct birds evolved in an isolated land, and without mammal predators, developed various levels of flightlessness, ground feeding and nesting habits, and fearlessness over millions of years.
Source: https://www.terranature.org/extinctbirds.htm
An example of the different stages of horoeka (lancewood). It changes as it grows to over moa height and develops much more lush green leaves.
Aotearoa’s Unique Plants
Science Learning Hub has a fantastic article all about our unique plants and why they are so special. Here’s an excerpt:
New Zealand plants are unique! New Zealand has some of the oldest primeval forests in the world, the largest type of moss and some of the largest tree ferns found anywhere. Many of the species are very similar to those growing on Earth in the time of the dinosaurs – and even earlier.
Aotearoa separated from Gondwanaland approximately 85 million years ago. The separation from Australia left New Zealand at least 2,000 km away 55 million years ago. This isolation from other land masses meant that, until humans arrived, plants were not replaced or competed with by other species from elsewhere. They continued to evolve alone – in this unique environment…. Fossil records also show that many of New Zealand’s plants are similar to those that were living on Gondwanaland. However, our indigenous flora and fauna have also had time to evolve into unique species: 82% of New Zealand plants are endemic – they are not found anywhere else in the world.
Want to know more? You can read this awesome article about all about our unique plants here. It explains the ways that they are so unique and special.
Aotearoa New Zealand- a unique land of birds
John Megahan, CC BY 2.5 <https://creativecommons.org/licenses/by/2.5>, via Wikimedia Commons
Eyles' harrier | Kērangi. Forbes’ harrier (Circus teauteensis). Image 2006-0010-1/35 from the series 'Extinct birds of New Zealand'. Masterton. Image © Purchased 2006. © Te Papa by Paul Martinson
When people first arrived in Aotearoa, it was a land of snowy mountains, thick native forest, and beautiful wetlands. Huge flocks of birds such as kererū flew overhead, towering moa strolled past, and kiwi kept people awake at night. Plants were full of lizards and insects. At night, tiny bats (the only native land mammal) flocked to flowering trees to drink nectar and while doing so, pollinate the flowers. Our country had many special animals found nowhere else in the world.
However, now Aotearoa is facing a biodiversity crisis with many of our unique species at risk of extinction. Species here evolved for millions of years without humans, or any other land mammals, apart from tiny bats. This meant that Aotearoa became a land dominated by birds. Some of our birds evolved very quickly to become giants. Moa became the tallest birds to ever walk the earth. Birds such as pouakai/Haast Eagle and kērangi/Eyles’ harrier (3-4 times the size of the harrier hawks that we see today) became apex predators, taking the place held by big cats in most other countries. The pouakai had claws the size of tigers’ paws and could sit on prey for days like lions do, meaning it could be much heavier than predatory birds in other countries that had to carry their prey.
As our animals evolved to hide from avian (bird) predators that hunted by sight, many of them evolved in unique ways. Lots of our birds and insects became large and flightless, they became nocturnal and relied on camouflage to avoid predation. Many birds nested on the ground, and even our bats spent much of their time crawling on the forest floor to find food. This worked well for a long time… until humans arrived.
Early Māori settlers cleared land and hunted birds for food. Moa only laid one or two eggs a year and could not reproduce quickly enough to survive being hunted. Sadly, when they disappeared, so did the hokioi which had suffered habitat loss, and then the loss of its main source of food. Māori also introduced kiore (rats) and kuri (dogs). These mammalian predators hunted on the ground, often at night and using smell. Our animals, that had evolved to be nocturnal, nest/forage on the ground, and rely on camouflage to avoid predation, were easy prey. A third of the native bush was cleared and 32 species of birds became extinct, including our endemic pelican, goose, and swan.
Then European settlers arrived, quickly clearing land for farms and cutting down trees for timber. A further 27% of our native forest was cleared in the decade 1890-1900 and huge areas of wetlands were destroyed, causing more habitat loss (we now have only 10% of our original wetlands left). Learn more about the importance of repo/wetlands here.
European settlers introduced many more mammalian predators including ship rats, cats, stoats, possums, and hedgehogs. Most of these had no natural predators here to keep them in check. Sadly, we have now lost nearly half of our native land bird species. You can read more about the loss of our birds here.
To learn more about the introduction of mammalian predators, why not play Ecological Bullrush? This is a great way for a class to learn this history in a fun way.
The Latest Statistics about our special biodiversity
Aotearoa is special. It has the highest percentage of endemic species (species that evolved here and are found nowhere else) in the world. However, in 2023, Stats NZ released an alarming report. It showed that New Zealand now also has the highest proportion of threatened species in the world. Our very unique biodiversity is at risk if we do not take action.
Many of our assessed indigenous species are categorised as threatened with extinction or are at risk of becoming threatened:
reptiles: 94 percent of species (116 of 124)
birds: 82 percent of species (178 of 217)
bats: 80 percent of species (4 of 5)
freshwater fish: 76 percent of species (39 of 51)
frogs: 75 percent of species (3 of 4)
vascular plants: 46 percent of species (1,253 of 2,744)
marine mammals: 22 percent of species (10 of 45)
Source: https://stats.govt.nz/indicators/extinction-threat-to-indigenous-species/
The two videos below were made by RNZ and support the Aotearoa NZ Histories Curriculum. We think they are great! They explain the early history of Aotearoa, including how our unique species evolved and the impact of human settlement on our environment.
What can we do? How can we help?
The combination of our animals evolving in such a unique way, the huge loss of habitat, and the introduction of mammalian predators has led to the current biodiversity crisis. You can help though! Educate those around you about how special our native species are and take action for the environment. You can help by planting native trees, restoring wetlands, clearing invasive weeds, and supporting community predator control efforts. Why not start in your own backyard, or by adopting a local gully or greenspace? If each of us did that, together we could make a big difference!
Our species are connected
Lennox, a student at one of the schools we work with, told us that he saw Aotearoa’s biodiversity and interconnected ecosystems as a game of jenga. All of our species are connected and rely on each other. If we remove a species others will become unstable or even fall out too. A great example of this is losing our pouakai/Haast eagle when their main food source, moa, became extinct. If we lose our pekapeka (bats), we will also lose the batfly and possibly dactylanthus, a unique plant that relies on bats for pollination.
As pieces are removed (become extinct) the tower becomes wobbly. Adding pieces on to the top of the tower (introduced species) makes it even more unstable. If we don’t act, it could collapse.
Activity: Maybe you could make a game of biodiversity jenga to help explain this concept to others?
Could collapse happen? If so, what would it look like?
Sadly, an example of ecosystem collapse can be seen happening in Guam, where the introduced brown tree snake has led to the extinction of every species of forest bird. This has led to an abundance of spiders, which now have no main predator, and forests dying due to no birds to spread seeds. (Read more about Guam’s ecosystem collapse here). We do not want this happening in Aotearoa!
Watch a great video about the situation in Guam here. Could this happen in Aotearoa?
Can we learn from the sad story of the huia?
The story of the beautiful friendly huia bird is a sad story full of lessons. Have we learnt from them? The full story can be read in this fantastic article by NZ Geographic. When the Duke of York, who later became King George, visited Whakarewarewa marae in 1901 a kuia placed a huia feather into the band of his hat. This gesture of generosity and respect, acknowledging his status at the time, began a chain events that would contribute to the extinction of this unique bird. Huia feathers for hats became fashionable in England and in New Zealand. Huia were already struggling due to habitat loss and being hunted (taxidermied pairs were prized by museums all over the world due to having the unique feature of different beak shapes for male/female). The fashion craze meant that the price offered for feathers rose considerably and the last remaining huia were hunted to extinction by 1907. Despite laws being in place to ban their hunting, and predator free islands being set up for them, they were worth too much dead to be saved. No huia ever made it to the island sanctuaries. Watch this video to hear how one man, Walter Buller, who loved the birds of Aotearoa and had researched them very thoroughly, also succumbed to greed. After helping set up island sanctuaries, he actually bought the birds destined for these safe places and sold them to wealthy collectors in England. Our last pair of laughing owls and one of the last live pairs of huia captured both ended up sent to a wealthy private collector in England, Lord Rothschild
Fashion contributed to the extinction of a species. With the issues currently being caused by ‘fast fashion’, we wonder if people are still putting fashion before the environment? What will the impact be and what story will future generations tell about this period of time?
Dr Mirko Junge, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons