Cost of living squeeze

Climate warming can induce a ‘cost-of-living squeeze’ in ectotherms by increasing energetic expenditures while reducing foraging gains. We used biophysical models (validated by 2,685 field observations) to test this hypothesis for ten ecologically diverse lizards in African and Australian deserts. Historical warming (1950-2020) has been more intense in Africa than in Australia, translating to an energetic ‘squeeze’ for African diurnal species, no net impact on Australian diurnal species, but generating an energetic ‘relief’ (by increasing foraging time) for nocturnal species. Future warming impacts will be more severe in Africa than in Australia, especially in summer, requiring increased rates of food intake (+10% per hour active for diurnal species). The effects of climate warming on energy budgets of desert lizards will be species-specific but predictable.