Maturation and reproduction in headstarted Blanding's turtles

Abstract Post‐release monitoring is key to ensuring that conservation interventions like reintroduction, reinforcement, and headstarting are effective. However, for long‐lived species, monitoring over sufficiently long time periods to confirm successful maturation and reproduction can be challenging. We use long‐term monitoring data to document post‐release maturation and reproduction by headstarted Blanding's turtles Emydoidea blandingii , a long‐lived late‐maturing species threatened by habitat loss and degradation, road mortality, and increased predation. We found that among headstarted Blanding's turtles, adult mass was attained in as little as 7 years, 3 years earlier than among non‐headstarted turtles. We documented successful reproduction by 29 headstarted females and courtship by 2 headstarted males, the youngest of which were each 10 years old. In comparison, the youngest reproductive non‐headstarted female and courting male were 11 and 12 years old, respectively. We found no difference in clutch size or reproductive frequency between headstarted and non‐headstarted females (mean clutch size = 12.5 vs. 13.5; reproductive frequency = 0.964 vs. 0.943). Hatch success differed between headstarted and non‐headstarted females depending on whether clutches were obtained by hormonal induction in enclosures (headstarts: 0.52; non‐headstarts: 0.83), by hormonal induction in the field (headstarts: 0.73; non‐headstarts: 0.74), or in maternity pens without hormonal induction (headstarts: 0.80; non‐headstarts: 0.98). We found no effect of female age on clutch size, hatch success, or reproductive frequency. Our results add to a growing body of evidence for the success of headstarting as a conservation intervention.