Issues

Summary: Contrary to expectation, parental care might not involve sustained, high-intensity activity; that is, it might not be ‘hard work’ and, consequently, costs of reproduction and physiological signatures of costs might rarely be experienced.

Summary: Recent biomechanical models of human foot function and experimental locomotion data from great apes suggest that the human foot evolved to facilitate both bipedal walking and running.

Summary: An asymmetric jamming avoidance response in a gregarious electric fish with a low-frequency electric organ discharge could function in communication as well as jamming avoidance.

Summary: We present a method for the automated measurement of upper thermal tolerance in small aquatic organisms from video data.

Summary: A new method for observing the behaviour of zooplankton using a machine vision system, used here to assess the effects of ultrasound on phototactic behaviour of salmon lice.

Editors' Choice: Synaptic processing in the hindbrain of infrared-sensitive rattlesnakes provides contrast enhancement and a potential basis for directional sensitive infrared motion recognition, reminiscent of computational mechanisms in the visual system.

Summary: In Pacific spiny dogfish, cardiorespiratory synchrony only occurs during progressive hyperoxia post-atropine, when heart rate is uninhibited and ventilation is slowed owing to the increase in available oxygen.

Highlighted Article: CT scans of fallow deer specimens show that the nasal cavities are likely to be involved in the production of their groans.

Summary: Exposure to an acute stressor downregulated testosterone production, but this effect was absent in chronically disturbed birds. The acute stressor had a strong effect on the testicular transcriptome, whereas chronic disturbance had a negligible effect.

Summary: Four cichlids of the Lake Victoria species flock raised under hypoxia exhibit a remarkable change in isohemoglobin pattern, corresponding with improved hemoglobin O₂-binding affinity.

Summary: Allometric investigation of hematological parameters and body fluid volume changes during simulated microgravity reveals that red blood cell count decrease is size independent, while extracellular fluid volume increase is proportional to body size.

Highlighted Article: A lightweight custom-made logger equipped with an inertial measurement unit (IMU) and GPS revealed head-gaze movement during homing flights in pigeons.

Summary: Caprimulgids and Australian owlet-nightjars displayed allometrically lower water losses compared with diurnal birds, whereas owls exhibited water losses comparable to those of similarly sized diurnal birds.

Summary: Wild African antelope show proportionality between capillary and mitochondrial investments of the heart, indicating economy of design at the cellular level of the oxygen cascade in an aerobic organ.

Summary: Physiological and biochemical process rates and, usually, behavioral responsiveness increase with temperature. Remarkably, rattlesnakes sensing warm moving targets with their facial pits are less responsive as body temperature increases.

Summary: Polypterus senegalus use intermittent high-intensity activity of fin and mid-body muscles during walking compared with more constant, moderate-intensity activity of all muscles during swimming.