Summary: Nectar-feeding birds employ unique mechanisms to collect minute liquid rewards from floral structures. This Commentary details the three stages of nectar feeding and suggests research pathways to expand our current knowledge.
Summary: Translocation-homing experiments reveal that non-territorial, non-migratory Rhinella marina can navigate to home areas following displacements exceeding regular, natural movements, suggesting a previously unconsidered prevalence of navigational abilities amongst amphibians.
Summary: The sixbar distichodus is a freshwater, plant-eating fish with an extra joint in its lower jaw that allows it to feed in new ways compared with fishes lacking the joint.
Discontinuous gas exchange in Madagascar hissing cockroaches is not a consequence of hysteresis around a fixed PCO2 threshold
Summary: Discontinuous gas exchange cycles in cockroaches do not arise from internal PCO2 oscillations around a fixed ventilatory threshold. DGCs continue when haemolymph PCO2 exceeds values recorded during continuous gas exchange.
Severe hypoxia exposure inhibits larval brain development but does not affect the capacity to mount a cortisol stress response in zebrafish
Summary: Severe acute hypoxia exposure in larval zebrafish significantly decreases forebrain neural proliferation but does not affect the long-term capacity to mount a cortisol stress response.
Editor's Choice: Three hummingbird species are capable of a temperature spectrum from normothermy to torpor, implying that some birds, at least, can precisely control their metabolic state.
Rapid blood acid–base regulation by European sea bass (Dicentrarchus labrax) in response to sudden exposure to high environmental CO2
Summary: European sea bass exposed to 1 kPa (10,000 µatm) CO2 regulate blood and red cell pH within 2 h and 40 min, respectively, protecting O2 transport capacity, via enhanced gill acid excretion.
Elastic energy storage across speeds during steady-state hopping of desert kangaroo rats (Dipodomys deserti)
Summary: The ankle extensor tendons of desert kangaroo rats store and return elastic energy in relation to hopping speed, recovering more energy at faster speeds.
Maternal food restriction during pregnancy affects offspring development and swimming performance in a placental live-bearing fish
Highlighted Article: Maternal food restriction during pregnancy results in smaller offspring, slower postnatal body fat gain and an inhibition of postnatal improvement of swimming skills during feeding, possibly leading to lower competitive abilities after birth.
Genetic variation in haemoglobin is associated with evolved changes in breathing in high-altitude deer mice
Highlighted Article: High-altitude variants in haemoglobin genes are associated with evolved changes in breathing that likely enhance O2 uptake in hypoxia in deer mice.
Behavioural responses of threespine stickleback with lateral line asymmetries to experimental mechanosensory stimuli
Summary: Stickleback with more mechanoreceptors have a stronger bias towards hovering with their right side adjacent to a surface when illuminated but a weaker bias in the dark.