A welcome swallow. Photo / Supplied
OPINION
One minute you're gliding along with grace, gravel crunching softly under your tyres, the cool morning air clearing away the cobwebs.
And then the next minute you get a face full of bugs. And then another. And another.
You can't seem to escape the bloody things. They're hovering in dark clouds, every 20 metres or so along the path, suspended in mid-air, at eye level.
You ride straight into them, there is nowhere else to go. There's nothing graceful about it.
You duck and weave and try to look down towards the ground, squinting and closing your mouth at the same time, while still trying to breathe in and occasionally glancing upwards to make sure you don't hit one of those ungainly pūkeko that have all of a sudden decided to play chicken – loping across the path in front of you at the last possible moment, their wings half-raised in the air and flapping about, as though the small stones on the path are hurting the soles of their feet as they run.
At that moment, what you need is a welcome swallow (Hirundo neoxena).
At that moment, what I needed was about 300 welcome swallows. A hungry flock, uncharacteristically flying in V formation in front of me, gorging themselves on small invertebrates. The clouds would part.
Welcome swallow is their common name (warou in Māori). These small, agile birds are thought to have made their way over to us from across the ditch sometime in the early to mid-1900s, a self-introduced species that are said to have been called "welcome swallows" because they would appear in southern Australia as a herald of spring.
They can be seen darting back and forth at high speeds all along Te Ara ō Wairākei reserve in Pāpāmoa, swooping here and there with their deeply-forked tails and long pointed wings, dive-bombing and chasing insects with precision and poise, popping back quickly to the nest, and then doing it all over again. "Hawking" is what that's called.
I couldn't help but think, as I rode along the reserve to work, digesting the bugs I myself had just inhaled, of a documentary I watched on Netflix the night before.
David Attenborough: A Life on Our Planet was still ringing in my ears.
The 94-year-old naturalist and broadcaster called the first half of the film his "witness statement".
"A story of global decline during a single lifetime," he said, delivering a powerful line in a way only he could.
He also said this: "Our imprint is now truly global. Our impact now truly profound. Our blind assault on the planet has finally come to alter the very fundamentals of the living world."
And this: "We have overfished 30 per cent of fish stocks to critical levels. We cut down over 15 billion trees each year. By damming, polluting, and over-extracting rivers and lakes, we've reduced the size of freshwater populations by over 80 per cent."
Those numbers hit you like a bug in the eye or a punch in the gut.
And there were more to come. One shocking statistic after another.
Then Sir David Attenborough quietly said the following, and his face and his voice as he said it left you well and truly winded.
"Human beings have overrun the world."
He looked every bit of 94 as he said those words. He looked tired. For a brief moment, he looked defeated. Heartbroken.
And yet, he still found the energy and the words to perk up and provide us with some hope and direction in the second half of the film.
"So, what do we do? It's quite straightforward," he said.
"It's been staring us in the face all along. To restore stability to our planet, we must restore its biodiversity. The very thing that we've removed. It's the only way out of this crisis we have created."
Biodiversity. It feels like we hear that word a lot now, more than we used to.
But I think that's only because a lot of us are just now starting to pay attention to it, as we register what declining biodiversity means for us.
As we start to look at the ecosystems around us – in our local parks and reserves, or at the beach – and realise what damage has already been done, and what is left.
And I think that's a pretty good place to start, actually – to stop and observe the natural world around you. In your backyard and in your neighbourhood. What's there? What's missing?
I decided to do that at Te Ara ō Wairākei. I did some reading and research, picked the brain of a local ecologist, and spent time observing and photographing the welcome swallows. I learned all about the complex food web playing out in front of me.
It starts with a foundational "soup" of oxygen, organic matter, nutrients, and sediment in the water. This soup provides the stimulus for aquatic plants and algae to grow.
Aquatic insects and molluscs (like snails) then feed on those plants and algae and lay eggs in and on the water. These eggs hatch into larvae.
The eggs and the larvae are eaten by fish and eels and ducks and pūkeko (which gobble up just about everything, including the plants).
Wading birds like stilts and white-faced herons also play a part, happily scooping up the larvae and insects, and catching fish, frogs and tadpoles.
Then, if the water is the right temperature and its flow is slow enough for long enough, some aquatic insect larvae go through metamorphosis to become flighted adults, and it's the turn of the smaller birds.
Welcome swallows, with their aerodynamic, streamlined bodies, are built for speed and so they thrive in an open area like Te Ara ō Wairākei. This species has benefitted from the clearing of bush and creation of open water areas, and it appears to be the main predator of flying insects in the reserve.
The native pīwakawaka (fantail), on the other hand, which also hunt insects on the wing, ideally need some bush around them to be successful.
They hunt best when surrounded by trees and shrubs, where they can out-twist and out-turn their prey. They also prefer to nest in that type of habitat. Pīwakawaka are present along Te Ara ō Wairākei but there are fewer of them, mainly around planted areas.
A myriad of other bird and insect and plant species chip in here and there – some have their niche, others aren't too fussy and might feed at different levels of the food web at different times.
Some birds prefer to forage on the ground for juicy earthworms, or snails. Others look under leaves or behind bark for insects and spiders. There's also kai to be found in the trees and shrubs and flowers.
The more species that co-exist like this in an ecosystem – the more diversity and competition there is at each layer of the food web – the stronger that ecosystem will be. The healthier it will be.
That is biodiversity. That is what we must grow and protect. Each species plays a part, even those annoying midges.
Without the small flying insects, the likes of the welcome swallow and pīwakawaka – with all of their remarkable aerobatics – will disappear. Without the birds, populations of midges and even mosquitos will boom to nuisance levels.
And it's such a fine balance. A slight change in water temperature or quality could alter the entire food web, for good or bad. It could change the number of aquatic insects that reach the flighted adult stage, or the diversity of aquatic insect species that survive and thrive.
That change – along with the number and diversity of plants, trees, and shrubs available – could alter how many birds you see, or what species of bird choose to nest, roost and feed along the reserve. It is all connected.
As Sir David Attenborough said in the film, uplifting music playing the background, "We must rewild the world."
How great would it be to see our native pīwakawaka giving those self-invited swallows from across the ditch some real competition?
Those flying bugs wouldn't know what's hit them.
Scott Yeoman is a freelance writer based in Pāpāmoa. He is a communications advisor at Ngā Pōtiki ā Tamapahore Trust.
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