(Rafferty Baker/CBC)

For five years, a pair of eagles has used a platform built by Vancouver city workers as their nest.

Every year, at least one eaglet has fallen to its death from the nest near Locarno Beach. When it was originally built, it was expected that the eagles would add to the platform, creating a better nest.

"It was never properly quite dressed with branches on the outside that the eagles could hold onto, and the young chicks were blowing off in the breeze and in their exercising had nothing to root themselves on," explained eagle expert David Hancock.

Arborists with the Vancouver Park Board climbed the 30-metre Douglas fir on Tuesday to improve the situation. A team including Alex Rothbauer, Justin Temple, Tatton Zanardo, park board biologist Nick Page and Hancock came up with the plan to stabilize the nest.

(Rafferty Baker/CBC)

Eagles are messy eaters.

A mess of bones, wings, feathers and debris could be found beneath the sturdy Douglas fir.

"What we were seeing is a lot of wings and feathers from — particularly from some gulls, seagulls that they've probably been predating, not just picking off as carrion," said Page.

"We saw lots of fish bones, everything from what looked like some sharks and some cod and things like that, some lingcod and then some stuff that you'd only find in urban environments."

(Rafferty Baker/CBC)

Each year, the nest has seen casualties.

Hancock and the Park Board have been monitoring the nest since it was built by a team of city arborists, which included Jody Taylor who tragically died on the job earlier this year.

"Generally, most nests don't lose [a chick], but this nest, every year lost one or two chicks for falling off or blowing off," said Hancock.

"These are not big house-building parents, partly because it's a platform. There's nothing to hold their sticks on and the wind blows them all off."

The park board snapped these photos of one of the eagles feeding its young on the aluminum-framed platform in May, 2013.

(Vancouver Park Board)

(Rafferty Baker/CBC)

City arborists don't usually spend their days building birds' nests.

"It's pretty easy. I'm going to fasten larger pieces and then start weaving smaller pieces in and then just take it as it comes," said park board arborist Alex Rothbauer, as though he'd done it before (he hadn't).

Fellow tree-climber Justin Temple has done a few bird-related jobs in his time as an arborist, but he'd never built an eagle's nest before Tuesday.

"I've done a couple wildlife structures, bird boxes, osprey platforms, stuff like that," he said. "Eagle's nest is a little bit more of the typical shape of what you'd envision a nest is. Like, an osprey platform is just flat, a bird box is a box, so this is going to be my first cliché nest."

"Usually, we're pruning for the structure of the tree and health and safety of the public, so this is a little different in that regard," said Temple.

But first, Temple and Rothbauer had to climb the tree using climbing spurs — big spikes strapped to the inside of each ankle to dig into the bark.

(Rafferty Baker/CBC)

(Rafferty Baker/CBC)

The park board's efforts are all part of getting Vancouverites closer to nature.

"As much as we're living in the city and we love our urban coffee places, breweries and everything, people really have a connection to the wildlife in the city," said Page.

"People are really proud of it. It's sort of part of Vancouver's identity as well, that we're the city really on the edge of wilderness, and I think this interest in eagles really speaks to that."

(Rafferty Baker/CBC)

(Rafferty Baker/CBC)

Workers hoisted prepared cedar boughs up to the nesting platform.

Once Rothbauer and Temple were at the top of their climb, they fixed a rope to hoist the nesting materials, beginning with large branches, to carefully attach the edges of the platform.

Fellow arborist Tatton Zanardo stayed on the ground, set up the loads and did a lot of the heavy lifting.

(Rafferty Baker/CBC)

(Justin Temple)

(Rafferty Baker/CBC)

After the solid outer branches, the smaller pieces were hauled up the tree and carefully put into place.

Once that was complete, the workers were satisfied that they'd left the bald eagles with a comfortable and much safer nest to return to.

(Rafferty Baker/CBC)

(Alex Rothbauer)

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