Once they are mature, they may reproduce for several years, but only a small fraction of turtle eggs survives to hatch and grow to adulthood.
(they; are; mature) (they; may reproduce; T:for several years; T:Once they are mature) (only a small fraction of turtle eggs; survives; to hatch and grow to adulthood)
they they only a small fraction of turtle eggs
are may reproduce survives
mature
T:for several years T:Once they are mature
to hatch and grow to adulthood