Issues

Summary: An animal's locomotion costs are governed by intrinsic and extrinsic factors. Animals can modulate these costs according to their priorities, which can be conceptualised as their individual energy landscape.

Summary: An actuated laser diffraction scanner for sampling large numbers of sarcomeres in whole muscle sections produces two-dimensional sarcomere length maps and shows excellent agreement with microscopy methods.

Highlighted Article: Mice modify their vocalizations in response to audiences, but not to simple social stimuli, constituting a novel paradigm for measuring the influence of social cues.

Summary: Navigating ants keep their head horizontally aligned, but not perfectly so, which has consequences for visual navigation.

Summary: Gamete traits, including sperm motility, play a strong role in sperm competition and fertilization; sperm chemotaxis promotes fertilization, and individual male fertilization correlates with sperm chemotactic behavior.

Highlighted Article: Electroantennography responses of male orchid bees are species-specific and particularly strong for some of their major perfume ingredients.

Summary: Testicular regression in quail in response to 8-h phase relation of 5-HTP and l-DOPA is GnIH induced, p53 dependent and Bax mediated, and this pathway reverses in hypertrophied 12-h quail testes.

Summary: Low oxygen and circulating trehalose availability constrain flight metabolism in the Glanville fritillary butterfly.

Summary: Seasonal acclimatization of the electrical excitability of the eurythermal roach increases pumping capacity of the roach heart by maximizing heart rate, but without compromising the stability of cardiac excitation.

Highlighted Article: An increase in sea turtle hatchling cohort size from 10 to 60 hatchlings decreases both the time taken to escape the nest and mean individual metabolic rate over this period by ∼50%, a phenomenon termed ‘social facilitation’.

Summary: By perturbing humans during walking, linear relationships are revealed between the resulting movement velocity of the body, and aspects of the ground reaction force.

Summary: The intense Manacus ‘wingsnap’ involves modified wing bones that, upon collision, are themselves the source of this unusual acoustic signal.

Highlighted Article: Mouthbrooding cichlids regularly use posterior-to-anterior waves of head expansion and significant inflow through the opercular slits to move the brood anteriorly away from the gills.

Summary: Heat dissipation may constrain physiological processes associated with compulsory heat generation (e.g. lactation), but is unlikely to constrain immune responses in mice.

Summary: Conservation of water may be of greater physiological importance than thermal tolerance to the tropical bee Austroplebeia essingtoni, which regulates humidity of the hive towards a microclimatic optimum.

Summary: The heme oxygenase-1/carbon monoxide (HO-1/CO) system is found in the developing zebrafish heart and plays an inhibitory role in setting the resting cardiac frequency.

Summary: Measurements of aerodynamic drag on a jackdaw indicate that lift-induced drag increases with wing flexing and with tail use, while tail use also increases body drag.