Feature image description: A Little Penguin, photographed at Perth Zoo | Credit: Cody Robinson
Near the HMAS Stirling naval base, a battle is being waged on the shores of Garden Island to protect its most elusive inhabitants.
Dr Belinda Cannell is a conservation ecologist with The University of Western Australia, whose decades-long dedication to little penguins has earned her the affectionate nickname ‘the penguin lady’.
Burrowing into her jacket against the wind, Belinda prepares for another day in the field. She visits the island fortnightly to survey little penguin nesting sites.
She records the number of occupied and empty nests, noting any penguins, eggs and chicks. Given the opportunity, she will microchip them and record weight and beak measurements too.
This data is added to a much larger dataset and used to monitor the island’s little penguin population, health and breeding success to better inform policy and decision making.
A PASSION FOR PENGUINS
As we travel to the island, Belinda reminisces about where her love for penguins began – during her PhD at Monash University in Victoria.
“I had an above-ground swimming pool that I set up on campus,” says Belinda.
“I got penguins from Phillip Island. I would catch all the fish for my experiments.
“I would put the fish in the pool and video the penguins swimming around catching different sizes and species of fish.”
Belinda studied the feeding behaviours of fledgling and adult penguins and examined the hydrodynamics – the way water flows around objects – of their bodies.
“Finally, I looked at the light levels penguins require to catch fish and proved that penguins are visual predators and require light to catch fish – that was my PhD.”
KEEPING A CLOSE EYE
The main little penguin colony lives on the shoreline among limestone boulders that form a rock wall. It’s a far cry from the stereotypically icy landscape other penguins inhabit.
Surveying the little penguin nests is difficult work. Some are easy to access. To inspect harder-to-reach nests, Belinda relies on her trusty ‘burrowscope’.
It’s a Bluetooth camera attached to the end of flexible, black PVC tubing that can transmit video to a small, wireless display screen.
Collecting accurate data isn’t easy. Belinda scrambles over rocks, squeezes her body into tight spaces and manoeuvres the burrowscope into position. She endures any cold, wet weather that comes her way.
SMALL BUT MIGHTY
Little penguins are the smallest and most human-shy penguin species in the world.
They weigh around 1 kilogram and stand 30-40cm tall. They have a unique, dark-blue coat of waterproof feathers and a white underbelly.
Belinda’s research helps science better understand little penguins and contributes significantly to conservation efforts.
She’s been sounding the alarm for decades about the threats facing the species.
UNDER THREAT
As a valuable indicator species, changes in their population, health, reproduction and foraging behaviours can signal shifts in ocean health and the ecosystem.
“If it’s a poor year for foraging and there isn’t a lot of fish, the penguins may be feeding on other things like jellyfish,” says Belinda.
Using data collected from 1986 to 2019, Belinda and other colleagues discovered that an extreme marine heatwave in 2011 caused a tropical fish species, more accustomed to warmer waters, to replace the major food source of the penguins from nearby Penguin Island.
Consecutive years of warmer sea surface temperatures and a likely reduction of fish prey close to the colony led to an 80% decrease in the population due mainly to poor breeding, starvation and parasitic infections.
While starvation is a serious threat, little penguins in this region are most vulnerable to boat strikes, with other threats including climate change, pollution and urban development.
EMPTY NESTERS
Today’s inspection turned up a lot of empty nests. But they aren’t always a cause for concern.
“Little penguins lay eggs any time from April to November,” says Belinda.
“So while a nest may be empty now, it could be occupied a few months later.”
Belinda has also installed 17 purpose-built nesting boxes, designed to allow the deployment of satellite and GPS tags to find out where they feed.
Feral foxes have made their way onto the island in recent years and have impacted some nesting sites.
“It’s really heartbreaking,” says Belinda.
Despite some setbacks, the Garden Island colony seems to currently be stable, unlike the marked declining trend from the neighbouring colony on Penguin Island.
A SILVER LINING
As the day nears its end, Belinda peers inside a nesting box and is greeted loudly by an adult female penguin.
She squawks in protest as Belinda lifts her out of the box to reveal a small, white egg.
Belinda is surprised to discover this penguin isn’t microchipped. The penguins that use these nesting boxes have been tagged, meaning this penguin is likely a new resident.
This is an encouraging sign for the colony’s population.
She quickly and carefully implants a microchip, weighs the penguin, measures her beak to verify her sex, then gently returns the penguin to her nest.
The microchips are crucial for the species’ survival. They are used to identify individuals over years and can determine a penguin’s colony of origin if it is injured and washes ashore on the mainland.
While the future of Rockingham’s little penguins is uncertain, Belinda’s work offers a glimmer of hope for their survival.