Embryonic and post-embryonic responses to high-elevation hypoxia in a low-elevation lizard

Area of Science:

• Physiological ecology
• Climate change adaptation
• Hypoxia research

Background:

• Species migration to higher elevations is a response to climate warming.
• The impact of high-elevation hypoxia on migrating animals is understudied.

Purpose of the Study:

• To investigate the physiological and developmental responses of low-elevation lizards (Eremias argus) to high-elevation hypoxia.
• To determine if low-elevation populations can acclimate to hypoxic conditions found at higher elevations.

Main Methods:

• Collected field body and operative temperatures of lizards from low (1036 m) and high (2036 m) elevations.
• Acclimated low-elevation lizards and their eggs to simulated low- and high-elevation oxygen conditions (18.5% O2 vs. 16.5% O2).
• Assessed adult thermal physiology, locomotor performance, growth, embryonic development (hatching success/time), and hatchling phenotypes.

Main Results:

• Low-elevation lizards exhibited higher body and operative temperatures than high-elevation counterparts.
• Acclimation to hypoxia led low-elevation adults to prefer lower body temperatures without impacting performance or growth.
• Hypoxia did not affect embryonic development or hatchling size and performance.

Conclusions:

• Low-elevation lizards can behaviorally thermoregulate to mitigate hypoxia stress during high-elevation migration.
• Embryonic development and offspring phenotypes are robust to high-elevation hypoxic conditions.
• Low-elevation populations possess adaptive capacity to buffer hypoxic impacts at higher elevations, ensuring similar fitness.