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.
METHODS & TECHNIQUES
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.
Evidence for an audience effect in mice: male social partners alter the male vocal response to female cues
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.
Head roll stabilisation in the nocturnal bull ant Myrmecia pyriformis: implications for visual navigation
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.
Apoptosis-mediated testicular alteration in Japanese quail (Coturnix coturnix japonica) in response to temporal phase relation of serotonergic and dopaminergic oscillations
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.
Oxygen and energy availability interact to determine flight performance in the Glanville fritillary butterfly
Summary: Low oxygen and circulating trehalose availability constrain flight metabolism in the Glanville fritillary butterfly.
Effects of seasonal acclimatization on temperature dependence of cardiac excitability in the roach, Rutilus rutilus
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’.
Center of mass velocity-based predictions in balance recovery following pelvis perturbations during human walking
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.
Determination of the wingsnap sonation mechanism of the golden-collared manakin (Manacus vitellinus)
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.
Heat dissipation does not suppress an immune response in laboratory mice divergently selected for basal metabolic rate (BMR)
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.
Evidence for a role of heme oxygenase-1 in the control of cardiac function in zebrafish (Danio rerio) larvae exposed to hypoxia
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.