The floods may be wreaking havoc for land dwellers, but many water birds are only benefiting from the rain. Even in the midst of tragedy and disaster, not all the news is bad. Find out why the birds that were in decline have having a baby boom now. — Global Animal

Wing and a prayer ... budgerigars on a mating mission. Photo Credit: Martin Willis

Sydney Morning Herald, Matt Buchanan

Has there been a better time to be a budgie? Has the pink-eared duck ever had it quite so good? And – is it just us? – are the pelican, ibis, egret and heron doing a bit more preening than usual?

From Lake Torrens in South Australia to the Mitchell Grass Plains in north-west Queensland, feathers are being fluffed and beaks are being buffed as millions of Australia’s inland bird species enjoy their biggest breeding boom in 20 years.

What makes it such good news, especially for the budgies, is that only last year they were dropping as fast as an Arkansas blackbird on New Year’s Eve. 

”It was very hot, and when there is extreme heat the water sources dry up, and there was no grain, and budgerigars are not big migratory birds so they were very hard hit,” said Chris Tzaros, the swift parrot recovery co-ordinator at Birds Australia.

”We heard stories of them flying straight down into large uncapped water drums, or tanks, and they were just drowning.”

Mass bird deaths are not particularly uncommon, although the hysteria generated recently by a few incidents in the northern hemisphere might have given a different impression.

In Arkansas, on New Year’s Eve, up to 5000 blackbirds were startled from their roost by fireworks and, unused to flying at night, crashed to their death.

On January 3, 500 red-winged-blackbirds fell on to a Louisiana highway. The next day 100 jackdaws were found dead on a road in Falkoping, Sweden, and days later 200 birds were found dead on a highway bridge in Texas.

Everywhere, pollution and poisons do their bit. Hereabouts extreme heat takes its toll.

In July 116 Carnaby’s black cockatoos dropped dead from heat stress when the thermometer touched 47 degrees in south-west Western Australia. Another 57 died two months later, killed by large hailstones.

But then La Nina turned up.

”The breaking of the dry is very important,” Mr Tzaros said. ”For example, budgies have a mass breeding event maybe once in 10 years, or longer. Right now you can see them in huge flocks.”

Mr Tzaros said the flooding would give many species the chance to recover their pre-drought populations.

But the ebb and flow of animal populations is a condition of existence in inland Australia.

Leo Joseph, the director of the Australian National Wildlife Collection and co-editor of Boom and Bust, said what was happening was normal in this environment.

”Australia’s desert avifauna has a number of species that can breed up in high numbers, and make use of that flush of productivity that comes from all that rainfall. You see pictures of budgies where there must be close to a million in a flock. But then they settle back down to lower numbers,” he said.

Dr Joseph said the budgie’s all-or-nothing cycle provided a good illustration of how fauna and flora had evolved to be in step with huge fluctuations in the climate and environment. It was also a demonstration of evolution.

”With evolution and natural selection we normally talk about survival of the fittest. With the budgies we see that nothing succeeds likes excess,” he said.

”When bird populations irrupt in these huge numbers they set up a selection event, where we see that the ones who make it though produce the offspring best suited to see it through to the next event.”

http://www.smh.com.au/environment/animals/flock-around-clock-as-bird-breeding-booms-20110114-19r9u.html

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