3. Maternal energy budgets
In 1980-2000, the maternal energy budgets of viviparous species are
projected to have been higher than those of oviparous species in most
regions (Fig. 5a, c). Maternal energy budgets of viviparous species were
estimated to have been relatively high at lower latitudes and
elevations, while oviparous mothers had low energy budgets
(<50 KJ) at sites where clutch numbers are high (sites with
low latitudes and elevations; see Fig. 3a). We estimate that climate
change generally decreases the energy budgets of oviparous mothers at
mid-low latitudes (except for some sites with high elevations; decreases
by -11.3% on average) (Fig. 5b). On the contrary, energy budgets of
viviparous mothers increase (by 21.2% on average) at most regions (Fig.
5d).
Under climate change, oviparous mothers would have a larger decrement in
energy budget as they produce more clutches (Fig. 5e). On the other
hand, viviparous mothers would have larger increment of energy budget
when they have a larger decrement in cost of prolonged gestation (Fig.
5f), while the slope of this correlation is steeper at regions with no
increment in litter numbers (blue points).