On the rise, one breeding pair at a time

Monday, 20 November 2023

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On the rise, one breeding pair at a time

Penguin colonies show first signs of recovery

After a tough few years, two beleaguered Little Penguin colonies in south-eastern Australia have shown signs of their recovery this year.

A former colony at Eden, on the South Coast of New South Wales, was reinvigorated three decades after breeding was last recorded there, when a paid waddled ashore and raised a single chick. The colony hadn’t been active since the 1990s, when predation from foxes, dogs and White-bellied Sea-Eagles, as well as sustained erosion of the colony all took their toll.

But these new penguins didn’t arrive by chance. Instead, they were encouraged to come ashore as the result of a concerted conservation effort to re-establish the colony.

First, foxes and dogs were excluded from the site, and then an area of artificial habitat was constructed, including artificial burrows made from concrete, replicating the ideal nest design.

However, despite the now favourable conditions, penguins would not be drawn to the former colony unless they could hear the calls of other penguins to lure them in. On land, penguins are quite vocal, giving a variety of calls ranging from yaps and grunts to trilling and braying. The resulting cacophony is the sign of a healthy colony.

To imitate this, researchers recorded the sounds of a flourishing penguin colony and broadcast them each night during the breeding season.

“We’re slowly coercing these birds into thinking this is a really good penguin colony site,” said Nicholas Carlile, of the Australasian Seabird Group, a special interest group of BirdLife Australia. “The penguins think ‘oh there’s a party, let’s go join it’.”

And as if lured in by the Song of the Sirens, a pair of penguins was drawn in to the colony and laid some eggs. Unfortunately, only one of the eggs hatched, but that chick survived to leave the nest, confirming the site as a functioning penguin colony for the first time in decades.

“The idea is to establish as many pairs as we can and eventually those pairs will produce enough young that those young will come back and keep the colony going,” he said. “Generally, about 10 per cent of chicks that fledge come back… it’s a very slow burn establishing a seabird colony.”

Meanwhile, at Victor Harbor, in South Australia, the penguin colony on Granite Island has increased slightly. During a penguin census of the island last month, volunteers counted 28 birds, up a little from last year’s tally of 26, though a number of new burrows were also found. Although the increase in numbers was slight, it reflects the increasing trend detected in the last few years; in the early 2000s, there were fewer than 20 Little Penguins living on the island, and it was feared that the colony was doomed.

The numbers pale into insignificance, though, when compared with the former population on Granite Island; it once supported more than 1600 birds.