A great egret looks for breakfast at Calamvale Creek

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Scientific stuff

Broad-shelled turtle
Also called
broad-shelled river turtle,
side-necked turtle,
broad-shelled snake-necked turtle

Species:
Chelodina expansa
(more recently, Macrochelodina expansa)
Family: Chelidae
Suborder: Pleurodira
Order: Testudines
Class: Sauropsida

Identification:
Large, long-necked freshwater turtle with very flattened pointy head and long, thick neck. Head, neck and limbs are grey.

Carapace (shell) is oval, wide, and flattened — broader at the tail end — and its colour may vary from grey to blackish brown. The plastron (the underneath part of the turtle's shell) is cream, and is narrower than the carapace.

Broad-shelled turtles are most often found in medium to large rivers, lakes and ponds, but also inhabit the larger parts of swamps, creeks, dams, and inland drainage systems.

They prefer cloudy water with considerable sediment, and like seclusion — lying concealed at the bottom of the water in sediment or debris. They are rarely seen except in autumn when females come out on land to nest, where they excavate a hole and lay between 5 and 30 eggs.

If you come across one on land laying eggs, stay well away, because if it is disturbed it will probably be scared off and not lay again for some time.

Size:
Adult carapace may grow to 50 centimetres (20 inches), and its head and neck are about 80 per cent as long as the carapace, making total length with neck extended up to about 80 centimetres (32 inches).

Personality:
Secretive, likes to be left alone. Doesn't like noise, excitement, or being disturbed. Definitely not a party animal.

Using our photos

Photos on this website are copyright. If you want to use any, email us at: creeklife@gmail.com

Betsy's photos

Betsy came out of Calamvale Creek to lay eggs at 11 a.m. on May 8. There had been 10 millimetres of rain at the creek earlier that morning, and the day was overcast.

The photographer said:
“I accidentally came across Betsy digging a hole in the grass about 50 metres from the creek bank.

“I had never seen such a large turtle in the creek, and had never seen one on land around here before. So my immediate reaction was to take photos of her because she was so close to me and the sight was so unusual.

“I wasn't sure what she was doing, and it was only when I got closer that I realized she could have been about to lay eggs.

“I found out later that my presence probably put her off laying, because broad-shelled turtles are very publicity-shy.

“After taking a few photos I left the area, but when returning a short time later I saw she was now high-tailing it back to the creek.

“She had left the hole about 7 centimetres deep and 9 centimetres wide without any eggs in it.

“I should now warn others that if you come across a broad-shelled turtle digging on land, then get away as fast as you can and try not to let it see you.”

Critters of Calamvale Creek

Betsy the broad-shelled turtle

Also called:
broad-shelled river turtle, side-necked turtle, broad-shelled snake-neck turtle

Chelodina expansa (more recently, Macrochelodina expansa)

Hello. I'm Betsy the broad-shelled turtle from Calamvale Creek in Brisbane, Australia. And I'm on my way to lay eggs.

broad-shelled_turtle_1 (41K)

I've been waiting for the right conditions for quite a while. Early this morning we had a good shower of rain, which softened the ground, and now the day is cool and cloudy. So this is the right time to come out from the murky bottom of the creek and find a nice spot in the sandy grass around the creek to lay my eggs.

Finding a spot to deposit eggs

broad-shelled_turtle_2 (35K) OK. This looks like a nice quiet spot. I'm a bit uncertain about all this egg-laying routine. I'm now 11 years old, with a carapace (shell) that is almost 28 centimetres (11 inches) long, and I've just reached maturity. This is the first time I've laid eggs.

I want to get the eggs buried in the ground this month, in May. The usual time for broad-shelled turtles to lay eggs is March-May — in autumn — before winter arrives. I like to hibernate over winter by burrowing into the mud on the creek bottom. Broad-shelled turtle eggs can take seven months to hatch if the ground temperature is warm enough, but if it is cool they may not hatch for more than a year.

My instinct tells me I should get away from the creek bank, because there are too many ducks, ibises, swamp hens and crazy dusky moorhens running all over the place there. I like privacy. So I've found this soft grassy spot about 50 metres from the creek that seems to be in a quiet neighbourhood. And the sandy soil has been softened by this morning's rain. Perfect!

Digging the hole for a nest

broad-shelled_turtle_3 (46K)

I use my back legs to excavate the hole. In the photo above my back left leg is in the hole scooping out the soil. My back right leg is scraping the soil backwards out of the way. (Clearer photo below.)

broad-shelled_turtle_4 (19K)The hole is now 9 centimetres (4 inches) wide and seven centimetres (3 inches) deep. I plan to make the hole 15 centimetres deep, so I am about half-way there.

I will lay 10 or more hard-shelled eggs that are about 3.5 centimetres long, and then partly fill the nest with soil.

I will then mix a special body fluid into the rest of the soil and use it as a plug over the hole to help in the long incubation.

The importance of leaving me alone

broad-shelled_turtle_5 (27K)Hey, what's this! A photographer has arrived and is watching me. Oh no! I hate people looking over my shoulder while I'm doing personal stuff. I wish he would go away. Maybe if I pull my head in he will think I'm a rock, and will leave me alone.

Now some other people have arrived. Oh dear! I wonder if I should abandon this whole egg-laying thing. I could just slip back to the creek and hide at the bottom and eat my favourite decapod crustaceans, aquatic bugs, and fish.

Back to the creek

Now the photographer has gone. But is he lurking nearby waiting to spy on me as soon I start depositing eggs? I think I'll have to get back to the creek where I feel safe.

chelodina_expansa_6 (16K)

Oh, I've got to cross this concrete path, and my neck is so long that it drags on the concrete. Ooch, ahhch, ouch — that burns.

broad-shelled_turtle_7 (26K)

At least I can now see the creek water, but that photographer is coming back from his walk. And those other people are taking photos too.

Lucky I can get my whole neck bent sideways under my carapace. They won't notice me now.

This is not a good environment for turtles to raise kids when people are gawking at you. I'm getting back to that creek as fast as I can.

chelodina_expansa_8 (47K)

People have to know they must leave us alone if they see us laying eggs. This has been such a bad experience I don't know when I'll want to lay eggs again. This just hasn't been a good day for me.

— Betsy the broad-shelled turtle

Happy note …

The turtle returns … and lays her eggs
See Betsy Part 2