Broad-shelled turtle eggs hatch
broad-shelled river turtle, side-necked turtle, broad-shelled snake-neck turtle
Chelodina expansa (more recently, Macrochelodina expansa)
The turtle eggs hatch
For several months I had been watching the area where 38 weeks ago I had seen Betsy the snake-necked river turtle lay her eggs.
Eggs of these broad-shelled river turtles (Macrochelodina expansa) can take between 192 and 360 days to hatch (roughly 18 weeks up to a year). So I had no idea when the hatchlings would decide it was time to come out and get down to Calamvale Creek, where their mother had come from.
But I did expect they would hatch after heavy rain. That was the time their mother had laid her eggs, and I realized rain would be needed to soften the clay so the little guys could dig their way out.
Every time there had been rain over the past few months I checked on the turtle nest.
Then on a very rainy February 12 — 270 days after Betsy had carefully laid her eggs in the nest — I found there was a small hole, about 5 centimetres (2 inches) wide, right above the nest (see photo above).
A closer examination showed it was a tunnel leading up from the eggs. The babies had hatched!
Seven turtle eggs
I left the area undisturbed for many days, then finally decided to dig very carefully around the nest to see how many eggs were there. I came into the centre of the nest slowly in case there were any unhatched eggs still inside.
I found seven chalky white, slightly marbled, egg shells, but one of the hatchlings had not survived. The shells were full of mud, no doubt because of all the rain since the hatchlings had emerged.
The big surprise for me was that the shells were soft and pliable, not at all like hard birds' eggs. They felt more like damp fine-quality paper.
One of the eggs was intact on one side, so I cleaned it and put it on the dirt to photograph it (below). This belonged to the turtle that hadn't survived.
It was broken on the side you can't see, and looked like it could have been broken since the time Betsy laid it. After all, she had to dig backwards without seeing what she was doing, so it's possible a rock fell back into the nest or Betsy had accidentally put her foot on it while laying.
Eggshells open like ribbon
The eggshells were very different in the way they had opened. Some had the small caps at the end separated; some had variously shaped holes in them, and others were just lots of small pieces.
One that especially interested me was the one below, which had unwound in a strip like a perfectedly formed ribbon.
How big are turtle eggs?
To give you a comparison of the size of the broad-shelled turtle's egg, I have placed one next to a small crested pigeon's egg and a large chicken egg (see below).
The crested pigeon's egg on the left is 30 millimetres long, the turtle's egg is 42 mm, and the large brown chicken's egg on the right is 57 mm.
Turtle hatchlings don't have a great survival rate. Kookaburras, butcherbirds, snakes and other predators abound. But because the day was so overcast and rainy, I suspect the six of these little broad-shelled turtle hatchlings at least made it down to the water.
— Robert Doolan
PS. See our photos of baby loggerhead turtle hatchlings. We photographed them on Mon Repos beach only a month after our creek turtles hatched. Boy, they're cute!