Issues

Summary: Oxidative damage with variable O₂ is lower in ectotherms than endotherms because of intrinsic and plastic differences in metabolism, which may be regulated by redox signalling.

Summary: Curvilinear walking slips induce more falls than those during straight walking, and attributes of the slip and stepping reaction depend on the slipped foot, path curvature and onset phase within stance.

Highlighted Article: The incomplete post-hepatic septum reduces the mechanical cost of breathing in the tegu lizard, even when abdominal volume has been increased.

Highlighted Article: A crow's attentional focus can be assessed by 3D tracking of their heads using a newly established motion capture system and behavioral experiments.

Summary: Human leg muscle architecture scales unexpectedly with body mass – muscle physiological cross-sectional area scales positively allometrically, whereas fiber length does not scale at all with body mass – which has implications for muscle function.

Highlighted Article: Male orchid bees concoct environment-derived perfumes for sexual signaling. In Euglossa imperialis, perfume load peaked early in male lives, suggesting that it communicates non-cumulative qualities, not age.

Summary: Under environmental conditions compromising vision interaction rules governing collective responses of fish schools to looming predators are modified to ensure efficient threat reactions.

Summary: Extreme climatic events, such as heatwaves, have the potential to reduce the growth and persistence of insect populations by negatively impacting reproductive rates, without necessarily affecting their survival.

Editors' choice: In addition to the Haller’s organ, black-legged ticks possess CO₂-sensitive structures important for tick host seeking, and their behavioral response depends on the animal's walking or stationary state.

Summary: Patterns of density-dependent metabolism extend beyond diploid phases into haploid phases – sperm exhibit metabolic plasticity in response to changes in density, which is likely an adaptive response to the presence of eggs.

Summary: Venous hemoglobin saturation profiles reveal a spectrum of cardiovascular dive responses in emperor penguins.

Summary: Doppler shift compensation during insect pursuit in a hipposiderid bat.

Summary: Birds oxidize more endogenous amino acids under acute water stress, supporting the hypothesis that dehydrated birds catabolize protein to offset water losses by synthesizing endogenous water.