Due to water warming….

Saltwater crocodiles, considered to be one of the most resilient species in Australia, have a weakness that could force them to migrate to southern waters, research from the University of Queensland has found.

UQ School of Biological Sciences Professor Craig Franklin and University of Queensland PhD student Essie Rodgers exposed juvenile saltwater crocodiles to long-term elevated water temperatures and found they spent less time submerged in water the warmer the water became.

“We thought that crocodiles, like many animals, would adjust to temperature changes as life continues,” Professor Franklin said.

“However, we were surprised to find they had little capacity to compensate for water temperature changes and seemed to be hard-wired to operate at certain temperatures.”

On average, saltwater crocodiles spend up to 11 hours a day submerged in water to avoid predators, to forage, to sleep or recover and for social interactions.

Ms Rodgers, whose PhD was originally going to look into the physiological resilience of saltwater crocodiles, said she was as surprised as anyone to find they were not able to adapt to a warming climate.

“Crocodiles are ectothermic animals, where environmental temperatures strongly influence their body temperatures,” Ms Rodgers said.

“Acute increases in water temperature resulted in significantly shorter crocodile dives.

“They weren’t able to remain submerged for as long, they had to resurface to replenish oxygen stores more often which resulted in less time under water.”

…..Professor Franklin said while they were unsure of exactly what effects the warmer water temperatures may have on saltwater crocodiles, it was likely they would migrate to cooler areas.

“We are not sure what this means, but it’s likely that if the water is too hot, crocodiles might move to cooler regions, or will seek refuge in deep, cool water pockets to defend their dive times,” Professor Franklin said.

Read more: http://www.smh.com.au/environment/climate-change/saltwater-crocodiles-may-move-south-to-flee-warmer-water-20151216-glop00.html#ixzz3uTJrhnAz

A boon for Tasmanian Biodiversity

I’d like to see them in Lake Burley Griffin. No budget surplus? In goes the minister responsible. That’ll make them try harder.

ruby said:

I’d like to see them in Lake Burley Griffin. No budget surplus? In goes the minister responsible. That’ll make them try harder.

you could build an official gangplank they could walk

If this had occurred earlier Steve Irwin may never have wanted to leave Essendon.

We visited Australian Zoo only a couple of weeks after SI died :(

They had previously tagged large saltwater crocodiles with tracking devices and it came as a huge surprise to me how far south one of them had actually reached. From memory, it was roughly the same latitude as Brisbane, but far out to sea.

Speedy said:

We visited Australian Zoo only a couple of weeks after SI died :(

They had previously tagged large saltwater crocodiles with tracking devices and it came as a huge surprise to me how far south one of them had actually reached. From memory, it was roughly the same latitude as Brisbane, but far out to sea.

A large croc was shot in the Coomera river on the Gold Coast around 1907 IIRC. I spoke to a ranger from NT who claimed to have tagger a croc in T which showed up on Christmas Island… they sure can swim distances.

pommiejohn said:

Speedy said:

We visited Australian Zoo only a couple of weeks after SI died :(

They had previously tagged large saltwater crocodiles with tracking devices and it came as a huge surprise to me how far south one of them had actually reached. From memory, it was roughly the same latitude as Brisbane, but far out to sea.

A large croc was shot in the Coomera river on the Gold Coast around 1907 IIRC. I spoke to a ranger from NT who claimed to have tagger a croc in T which showed up on Christmas Island… they sure can swim distances.

Quite a distance! For every one that makes it to an island, there must be thousands that die in the open sea.

Or east, or north west, or any other direction.

Any article with the word could in the title says nothing.

mollwollfumble said:

Or east, or north west, or any other direction.

Any article with the word could in the title says nothing.

So if we read in an article titled “Any article with the word could in the title says nothing”, that article would say nothing?

The Rev Dodgson said:

mollwollfumble said:

Or east, or north west, or any other direction.

Any article with the word could in the title says nothing.

So if we read in an article titled “Any article with the word could in the title says nothing”, that article would say nothing?

so if the temperature goes up 2 degrees the crocs will move south seeking 2 degrees lower

The Rev Dodgson said:

mollwollfumble said:

Or east, or north west, or any other direction.

Any article with the word could in the title says nothing.

So if we read in an article titled “Any article with the word could in the title says nothing”, that article would say nothing?

May and possibly fit the same criteria as well.

The Rev Dodgson said:

mollwollfumble said:

Or east, or north west, or any other direction.

Any article with the word could in the title says nothing.

So if we read in an article titled “Any article with the word could in the title says nothing”, that article would say nothing?

To be fair “could” should have been written thus.

ruby said:

I’d like to see them in Lake Burley Griffin. No budget surplus? In goes the minister responsible. That’ll make them try harder.

We have similar minds.

Michael V said:

The Rev Dodgson said:

mollwollfumble said:

Or east, or north west, or any other direction.

Any article with the word could in the title says nothing.

So if we read in an article titled “Any article with the word could in the title says nothing”, that article would say nothing?

To be fair “could” should have been written thus.

The point is that no prediction of future events is certain, so it is perfectly reasonable and correct to use the word “could” in the title of an article, and silly to dismiss the entire article because of that word.

Oh yeh this is great science!

Ms Rogers said “The water temperatures used in the research ranged from 28 degrees celsius, reflective of current summer temperatures, up to 35 degrees celsius, the potential water temperature levels expected in extreme climate change models.

For sure!

My take on this is -

below, marked in yellow boundary, is where the toothy critters live (centered around the hottest place on earth, the equator)

Now based on the extensive research of Ms Rogers, over millenium,

below, again marked in yellow, is the boundary where I expect to the toothy critters to be living in Australia
by the year 2030
.
.
.
.
.

The_observer said:

.
.
.

On further research, using extreme climate modelling, and with input from Ms Rogers, & The Sydney Morning Herald,
I have produced a global map showing crocodile distribution expected by the year 2042,

again marked in yellow
.
.

They’ll never make it – sharks would get them all.

The Rev Dodgson said:

The point is that no prediction of future events is certain, so it is perfectly reasonable and correct to use the word “could” in the title of an article, and silly to dismiss the entire article because of that word.

I tend to disagree. The word “could” is used to justify sloppy work. On its own it means nothing, because very little is impossible. As for crocs, of course they could move south, it makes sense for them to evolve to cover a wider ecological range.

Further, the discovery of saltwater crocs in the NT is what caused the first great influx of people into the area.

mollwollfumble said:

I tend to disagree. The word “could” is used to justify sloppy work.

It could be.

party_pants said:

They’ll never make it – sharks would get them all.

16ft crocodile vs 13ft shark.

IMHO, any animal that find itself out of its preferred environment when it meets it match will die. A crocodile in the open ocean would not be a match for a shark of this size. A shark beached on a river bank will become a croc’s dinner, as has been recorded numerous times.

They must just take a single bite out of each other and go their separate ways.

I think it’s safe to assume that crocodiles have undergone more than a few climate changes in their history and a few slow migrations over an extended period last of time won’t worry them.