Animal Physiological Ecology

Animal physiological ecology explores how organisms adjust internal functions—in metabolism, respiration, redox balance, hydration and circulation—to meet the challenges of their environments. Central themes include the energetic demands of endurance activities such as migration and diving, the regulation of oxidative stress during sustained aerobic performance, the modulation of haematological and mitochondrial traits under changing seasonal or altitudinal conditions, and the balance of energy acquisition against maintenance costs. By linking mechanistic insights at cellular and organ levels to ecological patterns of distribution and behaviour, this field reveals how global‐scale pressures—climate variability, habitat alteration and resource fluctuations—shape the physiological strategies that underpin survival, growth and reproduction across taxa.

Research from Nature Portfolio

Seasonal flexibility in mitochondrial function has been demonstrated in long‐distance‐migratory White‐crowned Sparrows, where preparatory up‐regulation of citrate synthase activity and oxidative phosphorylation capacity in spring and autumn allows a reversible boost in ATP production under peak flight demands. In long‐lived shorebirds such as Hudsonian godwits, the pre‐migratory period is marked by a coordinated increase in total antioxidant capacity alongside reduced lipid peroxidation, despite elevated basal metabolic rates, indicating proactive redox defences that limit cellular damage during non‐stop ocean crossings. A broad phylogenetic survey of avian species shows that fully migratory birds possess higher haemoglobin concentration and haematocrit than partial migrants or residents, with altitude also predicting elevated red‐cell traits, highlighting haematological modulation as a key adaptation to variable oxygen and energetic requirements.

Research from all publishers

Experimental work on migratory passerines has revealed an energy–oxidative cost trade‐off when using polyunsaturated fats as fuel: an omega‐6‐rich diet reduces energy expenditure in prolonged flight but accelerates long‐term oxidative damage, underscoring fuel composition as a determinant of performance versus longevity. Field studies tracking nocturnal migrants crossing alpine passes show that fat catabolism dominates early in flight, with a programmed slow descent before landing that reduces energy expenditure by up to 30 %, conserving fuel and easing post‐flight recovery. A synthesis of captive‐bird and field observations confirms that migratory birds synchronise buildup of fat reserves with up-regulation of antioxidant systems prior to departure and employ dietary and habitat‐mediated antioxidant replenishment during stopovers.

Animal Physiological Ecology publication trend

The graph below shows the total number of articles in animal physiological ecology across all publications each year (not limited to Nature Index journals).

Technical terms

Mitochondrial respiratory performance: The capacity of mitochondria to consume oxygen and generate ATP through oxidative phosphorylation, often measured by enzyme activities such as citrate synthase or state-3 respiration.

Reactive oxygen species (ROS): Highly reactive by-products of aerobic metabolism that can oxidise lipids, proteins and DNA unless neutralised by antioxidant systems.

Fatty acid catabolism: The β-oxidation of stored lipids into acetyl-CoA units that fuel the tricarboxylic acid cycle during sustained energy demand.

Total antioxidant capacity: The integrated ability of enzymatic and non-enzymatic defences to scavenge ROS and prevent oxidative damage.

Haematocrit: The volume fraction of red blood cells in blood, reflecting oxygen-carrying capacity and influencing aerobic performance under hypoxic or high-altitude conditions.

References

1. How Birds During Migration Maintain (Oxidative) Balance. Frontiers in Ecology and Evolution (2021).
2. The energy savings-oxidative cost trade-off for migratory birds during endurance flight. eLife (2020).
3. Energy supply during nocturnal endurance flight of migrant birds: effect of energy stores and flight behaviour. Movement Ecology (2024).
4. Flexibility underlies differences in mitochondrial respiratory performance between migratory and non-migratory White-crowned Sparrows (Zonotrichia leucophrys). Scientific Reports (2024).
5. Oxidative status and metabolic profile in a long-lived bird preparing for extreme endurance migration. Scientific Reports (2019).
6. Haematological traits co-vary with migratory status, altitude and energy expenditure: a phylogenetic, comparative analysis. Scientific Reports (2019).