As newborns, all we want to do is eat, drink and sleep. But could you imagine if you had to break out of a shell and struggle to survive instead? Welcome to life as a turtle! In this update article we explore the life cycle of the Blanding’s turtle, with a video of a cute baby turtle hatching to boot!
After mating in a wetland, pond or shallow lake, adult female Blanding’s turtles look for the perfect spot to lay their eggs in May. Does the potential nesting site have moist sandy soil? Is it open and sunny? If so, then the females get ready to make their nests. In some populations, a female Blanding’s turtle can travel up to 2 km to find her preferred nesting site, a trip that can take as many as 10 days. If preferred nesting sites are not available, females may nest in lawns, gardens or along gravel road edges.
Females start to dig the nest using their back legs. The nest is complete when it is about 17 cm deep with a 7-10 cm wide opening. She will then lay 4-13 eggs at a time (clutch of eggs), before heading back to the wetland.
After 60-128 days the eggs will hatch (usually around August). When eggs hatch depends on the temperature of the local environment. Busting out of a shell is no easy feat, but these little guys get cracking when they’re ready to break free. Take a look at this video:
It can take a baby turtle (hatchling) up to 3 days to completely break free from its shell. Hatchlings are armed with a special adaptation called an egg tooth (“caruncle”). The egg tooth will fall off about an hour after hatching, but is very important for helping the hatchling pierce through the tough-to-crack eggshell. As you can see from the video, our baby Blanding’s turtle, like other turtles, hatch with part of their egg yolk sac attached to the underside of their shell or plastron. This yolk sac provides nutrients to the turtle during development in the egg and for the first few days after it has hatched. Then the yolk sac is absorbed by the turtle’s body through a small crack in the plastron, which later fills in.
If the temperature of the nest is 22-28C, the turtle hatchlings will be male. If it is above 29C, the hatchlings will be female.
Getting to the Wetlands
Since the mother turtle returns to her summer wetland habitat once she has laid her eggs, the new hatchlings must find their own food and a way to the wetland by themselves. This means they might have to travel long distances while under threat from predators. Hatchlings are easy targets because their defence is limited and they have relatively soft shells until they are a little older.
If they are lucky enough to reach the wetlands, baby Blanding’s turtles stand a much better chance of surviving. As winter approaches, adults and young turtles hibernate for the winter by burying themselves in the soft, mucky bottom of wetlands, ponds or lakes (October-April).
Blanding’s turtles are slow growers. On average, it takes about 20-25 years before they are ready to lay eggs of their own. However, as adults, they have a strong shell that can protect them from predators and help them live a long, healthy life. In the wild, Blanding’s turtles live up to 80 years and some can even reach 100 years old.
Waiting so long before they have young (“delayed sexual maturity”) has its benefits. It allows them to have better quality offspring or increase the number of young per breeding event, and decrease mortality risk as an adult. However, delayed sexual maturity means some of the younger turtles may not survive long enough to reproduce. Since adults don’t breed until 20-25 years of age, and they only breed once every few years, it takes longer for the population to grow. That’s why it’s so important that we protect them!
Toronto Zoo Update
The Toronto Zoo has a great program that helps Blanding’s turtles survive their fragile first few years by providing them with a safe place to hatch and grow.
This year Earth Rangers is teaming up with the Toronto Zoo to help Blanding’s turtles. In May-June 2012 researchers collected 10 eggs from at risk nests as part of the Toronto Zoo’s head-starting program. These eggs wouldn’t have survived in the wild because of where the nests were located. The eggs were brought back to the Toronto Zoo where they were put in a special incubator until they hatched from August 6-9, 2012.
In May-June 2013 Toronto Zoo scientists collected and incubated another 24 eggs from three at risk nests. Half of all the eggs were incubated at 27.5C and half at 29.5C, meaning that the hatchlings would be 50% male and 50% female. Twenty-two of the 24 eggs collected hatched between August 8-16, 2013. Hatching success of the 24 eggs collected in 2013 has been 22/24 (92%)! The remaining two eggs were infertile.
The Toronto Zoo now has 32 young Blanding’s turtles growing safely in their head-starting program. Scientists weigh them regularly and check to make sure they are healthy. The 10 turtles from 2012 will be released into the wild during spring 2014, and the other 22 turtles will be released in spring 2015.
The Blanding’s turtle Bring Back the Wild project is already off to a strong start. When you sign up for a Bring Back the Wild campaign your donations will help these Blanding’s turtles.
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