10.5061/DRYAD.3R2280GFQ
Clarke, Leo
0000-0002-1600-6197
Bangor University
Elliot, Rebecca
Bangor University
Abella-Perez, Elena
Estación Biológica de Doñana
Marco, Adolfo
Estación Biológica de Doñana
Martins, Samir
0000-0003-3156-9630
BIOS.CV
Hawkes, Lucy
0000-0002-6696-1862
University of Exeter
Low-cost tools mitigate climate change during reproduction in an
endangered marine ectotherm
Dryad
dataset
2021
FOS: Earth and related environmental sciences
World Wide Fund for Nature
https://ror.org/011590k05
Newport Aquarium*
Newport Aquarium
2021-03-24T00:00:00Z
2021-03-24T00:00:00Z
en
12176 bytes
3
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
The impacts of anthropogenic climate change will be most dramatic for
species that live in narrow thermal niches, such as reptiles. Given the
imminent threat to biodiversity, and that actions to reduce carbon
emissions are not yet sufficient, it is important that a sound evidence
base of potential mitigation options is available for conservation
managers. Successful incubation and production of male sea turtle
hatchlings is threatened by increased global temperatures (sex is
determined by the temperature at which eggs incubate). Here we test two
conservation tools to reduce incubation temperatures: clutch splitting and
clutch shading, on a nesting loggerhead turtle (Caretta caretta)
population in the Eastern Atlantic Ocean. During the thermosensitive
period of incubation, split and shaded clutches were both 1.00 ˚C cooler
than control nests. Clutch splitting (mean: 45 eggs) reduced nest
temperatures by reducing metabolic heating during incubation compared to
controls (mean: 92 eggs). Modelled primary sex ratios differed between
nest treatments, with 1.50 % (± 6 % S.E.) females produced in shaded
nests, 45.00 % (± 7 % S.E.) females in split nests and 69.00 % (± 6% S.E.)
females in controls. Neither treatment affected hatchling size, success,
mass or vigour. When clutch splitting was repeated two years later, hatch
success was higher in split clutches compared to controls. Synthesis and
Applications: Clutch splitting and clutch shading successfully altered the
thermal profile of incubating turtle nests. When there is sufficient
knowledge to better understand the effects of intervention on fundamental
population demographics, they will be useful for reducing incubation
temperatures in sea turtle nests, potentially increasing nest survival and
male hatchling production. The effect of clutch splitting in reducing nest
temperature was lower relative to clutch shading, but requires
significantly less funding, materials and specialist skill, key factors
for management of turtle rookeries that are often in remote,
resource-limited areas.
Data were collected through fieldwork carried out on Boa Vista island,
Cape Verde. Temperature data were recorded from incubating turtle nests in
three treatments: "split" or halved nests, control nests, and
shaded nests. Incubation temperatures were calculated and published
equations used to calculate hatchling sex ratios. Hatch success, hatchling
fitness, size and vigour were all recorded.