Bitterns lift off, more than just a few
Lake Cullen near Kerang has cemented its place as one of Australia’s premier wetlands for native birds, with an astounding discovery in May.
North Central Catchment Management Authority (CMA) contracted ecologist Damien Cook to make some observations of bird numbers at Lake Cullen in mid May, after a recent wetland flow.
“We were blown away by what he saw,” North Central CMA Environmental Water manager Louissa Rogers said.
“At one stage there were at least 16 Australasian bitterns taking flight, and that looks like being a conservative estimate.
“To have so many in the one place, on the one wetland is amazing. Their breeding season is in spring, so seeing this at any time of the year is significant.”
The Australasian bittern is also known as the Australian bunyip bird, because of the noise it makes during breeding season.
There could be as few as 1000 adults left in the world, a statistic that has them listed as globally endangered.
Australasian bitterns are rarely seen, and flocks of more than five are considered significant.
Matt Herring is an ecologist and an Australasian bittern expert. His Bitterns in Rice project tracks breeding bitterns that descend on the rice crops of the New South Wales Riverina each year.
He said the numbers at Lake Cullen highlighted the value of the wetland, and the entire Kerang Lakes region.
“It is very rare to have that many bitterns in one place,” he said.
“In the past five years, there have been fewer than 10 Australian wetlands known to have supported 16 or more Australasian bitterns, including during breeding season.
“The other important part of this, and this the same for most waterbirds, is that if they can find a winter refuge like Lake Cullen, they don’t have to make the yearly arduous journey to the coast to find suitable habitat.”
In recent years, the nearby Hirds and Johnson swamps have been home to a handful of breeding bittern.
“The Kerang Wetlands are significant on a world scale, and is internationally recognised and protected under the Ramsar Convention,” Ms Rogers said.
“Over autumn, we have filled Lake Cullen, with the aim of creating an environmental honeypot for the whole region.
“The 2016 floods allowed us to fill Lake Cullen, an opportunity that doesn’t come along that often.
“Because of its size, salinity and temporary nature, it has a diverse range of plants, bugs, birds and fish and when there is water in it, it is a big and important feeding ground for the entire region.”
Managing water to look after our valuable wetlands is part of the State Government’s broader $222 million Water for Victoria initiative to improve the health of waterways and catchments across regional Victoria.
The flow is in line with the Seasonal Watering Plan’s wet scenario actions. The Victorian Environmental Water Holder’s Seasonal Watering Plan 2016-17 is available to download from www.vewh.vic.gov.au, and regular updates are posted on the North Central CMA website.