‘We’d come here to get away from bickering about screens but had plunged back further: to the Eocene’

M y son and I drive 10 minutes from home to the venerable Fairfield Park boathouse. We study a list of river faring craft and choose a two seater kayak. He likes sitting at the front, he tells me, so he can pretend he’s alone. I like sitting at the back so I can watch him grow before my eyes. On the river we make a show of synchronised paddling but, when we’re out of sight, we let ourselves drift downstream.

Eucalypts overhang the water and we float through reflections of twisting branches, making them ripple. Ducks come and race us. Parrots skitter through the trees that line the banks. Only the appearance of a bridge connecting the Eastern Freeway reminds us we’re mere kilometres from Melbourne’s city centre.

We float under the bridge. The pylons’ graffiti is blurred by a brown watermark left by heavy rain. Overhead the traffic roars. There’s also a noise of a different pitch. “Do you see what I see?” my son asks. Growing in a distant tree are bulbous black sacks. We have passed ribbons of shredded plastic in shrubs along the riverbank, but these are like full sized shopping bags and they hang even from the highest branches.

One of the bags jerks as if stuffed with a creature – it is a creature. Sign up for a weekly email featuring our best reads Drifting further, we realise that as far as the eye can see, roosting in every branch of every tree, are grey headed flying foxes, Australia’s megabat. The sound is extreme.

Around us, they screech and twitch and stretch. Unfurling membranous wings, the bats flash the orange fur of their collars before recloaking themselves. Two joggers come past along the bank. “Look, fellow humans!” my son exclaims. The joggers are fit: we track their exertions through the bushes, then we’re on our own again.

We’d come here to get away from bickering about screens, but had plunged back further, some 50m years The air in a bat colony is acrid. I try to direct us toward the centre of the river where the tree canopies don’t reach so as to lessen the chance of being tagged. ‘This is a horror movie. With our luck one of these will be a vampire.” “Do you want to turn back?” I ask.

“Definitely not.” The point of a horror movie is fear crashing into excitement. Other families may have spread on to the country’s finest beaches, but how often do you travel an inner city waterway and happen upon “bats, bats, bats, and more bats”? We’d come here to get away from bickering about screens but had plunged back further, some 50m years to the Eocene.

Now it was just the two of us and a summer camp of 30,000 prehistoric creatures, doing what they’ve been doing for time immemorial, working out whose territory was whose, and who would mate with whom on that territory. And, floating past, it seemed we could hear every shrill detail of the negotiations.

Melbourne has treated the Yarra River terribly – but it doesn’t have to stay that way Read more The grandparents of these bats moved to this area in 2001. Melbourne’s vulnerable flying fox population, having outworn their welcome in the Botanic Gardens, was in danger of being culled. At the last perilous minute they were saved when hundreds of volunteers stood in the gardens one autumn dawn and in unison switched on stereos, beat pots and pans, and clanged garbage cans and lids until they drove the bats from the gardens and eventually in to Yarra Bend Park, the largest area of bushland left in the city.

When we finally float to the end of the colony, we are dazed. But we need to turn around. We need to get back to the boathouse before we lose our$20 deposit, and this requires paddling upstream. At 3.30 in the afternoon the bats seem more agitated. The kayak and the water around us darkens as one then another bat flies overhead.

Perhaps we’ve woken the colony, or perhaps they were already stirring, making preparations to spend the night flying all over greater Melbourne, searching for nectar and pollen from eucalypts, or lilly pillies, or banksias, or suburban fruit trees – figs being a special favourite. Dispersing seeds on their journeys, they pay it forward, so to speak, for other generations of bats.

Then, by sound alone, mother bats find their way straight back to their children – presumably to pick up the squabble where they last left off. As we make our way upstream my son’s every stroke scoops water over me. Turning to glance behind us, I hit him on the head with my paddle. And we are arguing about who is paddling harder, and which of us is at fault when our oars smash against each other.

And yet, as more bats patrol overhead, there are moments when miraculously he and I coordinate our strokes and we’re in time together, surging up the river, with the sun hitting the water, bathing us in sparkling light. Chloe Hooper is an author and nonfiction writer whose books include The Arsonist, Bedtime Story and The Tall Man..