Coastal dips and river wading on a multi-day hike through New Zealand’s Abel Tasman National Park

This article was produced by National Geographic Traveler (United Kingdom).

With its immense buttressing roots and leathery green leaves, the northern rātā tree should not be underestimated. Carried by the wind, its seeds land in the crowns of neighboring trees and begin to germinate. Then, for hundreds of years, the spider roots of each individual seedling wrap around their host, burying it and consuming the rotting trunk.

“It operates on a totally different time scale than humans,” says guide and outdoor educator Rod Morrison, as we stand at the base of a gigantic rātā that he estimates is 1,000 years old. “Other guides may be interested in mushrooms or birds, but I love symbiosis: how different species relate to each other.

”We are just a few hours into our hike through Abel Tasman National Park, a protected paradise located on the northern tip of New Zealand's South Island and one of the country's smallest national parks. Over the next three days, I will walk the 37-mile Abel Tasman Coastal Trail and watch from this Great Seaside Walk for dusky dolphins, fur seals, little blue penguins and wekas, a land bird famous for raiding tents looking for of sandwiches.

We have already sailed through tannin-hued marshes, deep rainforest tunnels and beaches dotted with tide-beaten rocks. Rod is a guide for Wilsons Abel Tasman, a family-owned water taxi and tour operator with roots in the park as deep as his trees. He has given me a quick introduction to the flora of the reserve, teaching me how to eat the tender shoots of the hardy supplejack vines, which plants can read my future, and which can cure an upset stomach when boiled into tea.

The rhythm is calm. Together, we venture into high forests where the trees sport tutus of branching kiekie palms, and then climb a series of modestly steep switchbacks. While the coastal path is well signposted and would be easy to follow if walking alone, I would find the tidal estuary crossings quite daunting. Timing is key: walk too fast or too slow and you risk being blocked by the rising tide, forcing you to detour for hours through the mountains. Fortunately, Rod has been hiking these trails since he was a child and is intimately familiar with the park's aquatic rhythms.

It helps that you also have some contingencies up your sleeve. We reach our first tidal crossing and discover that a swollen inlet has made our passage impossible, but Rod has called ahead and a barge is waiting for us. We take off our socks and shoes to walk to the boat in knee-deep cold waters and are transported to the historic Meadowbank Homestead, one of two lodges hosted along the trail.

Built almost 60 years before the national park was officially formed in 1942, Meadowbank was home to generations of the Wilson family, but now welcomes a succession of trail-weary visitors looking to rest and fill their bellies with a homemade food. While I wait for dinner, I peruse the family artifacts on display, including antique telephones, sewing tables, and charmingly awkward photographs of lanky Wilson teenagers peeling potatoes on the beach at Christmas.

The next morning we crossed a marsh at low tide and followed Rod's secret detours along overgrown goat trails to skip the less interesting sections of the trail. As the day progresses and we meander between beaches and forests, I realize that the sea has been our constant invisible companion, animating us with its melodic clashes even as it remains hidden behind dense trees.

Layered against this background track, I can make out the flutter of tiny wings as bronze-breasted fantails flutter through the bushes, and kākā calls ring like bells overhead. With its dusty olive-colored feathers, this endangered endemic parrot species is easy to hear but difficult to spot. My first encounter with one is with its shadow, its wide wingspan gives me a dizzying thrill when it passes over me.

“It wasn't long ago that you heard birds singing in the park,” Rod says, remembering a childhood when the trees were silent. "These birds evolved without predators and were completely helpless when rats, weasels and other vermin arrived with the first Europeans."

A joint effort between the New Zealand Department of Conservation and supporting NGOs has helped eliminate these pests and increase native bird populations. Now the forests sing again. From a cliff overlooking Adele and Fisherman Islands, Rod explains how bird calls were played over speakers to attract birds to migrate to the park.

The sunset is being drowned out by woolly clouds as we emerge from the Torrent Bay bushes. We cross the beach to the Wilson family's second lodge, where we will spend the night. At dinner, Rod mentions that the bay glows a lovely blue with bioluminescent plankton in good weather, so after cleaning my plate, I crawl to the water's edge to try my luck. I test the waves with a handful of sand and... nothing.

Standing timidly in the dark with my tired feet sinking into the wet sand, I look out over the blackened bay, tasting the salt in the air and listening to the birdsongs bidding me goodnight in the estuary behind me. This is all the magic I need.