And that 's vital for them : if they 're not independently mobile by the time they 're seven or eight , they 're left in the sand to die .
Some of them have taken their first steps over the last few years .
That 's vital for them : if Some 're not independently mobile by the time Some 're seven or eight , Some 're left in the sand to die .
Some of them have taken their first steps over the last few years .