Subspecies differences in thermal acclimation of mitochondrial function and the role of uncoupling proteins in killifish [RESEARCH ARTICLE]
Heather J. Bryant, Dillon J. Chung, and Patricia M. Schulte Thermal effects on mitochondrial efficiency and ATP production can influence whole-animal thermal tolerance and performance. Thus, organisms may have the capacity to alter mitochondrial processes through acclimation or adaptation to mitigate these effects. One possible mechanism is through the action of uncoupling proteins (UCPs) which can decrease the proton motive force independent of the production of ATP. To test this hypothesis, we examined the mRNA expression patterns of UCP isoforms and characterized the effects of thermal acclimation and putative local the...
Source: Journal of Experimental Biology - October 23, 2018 Category: Biology Authors: Bryant, H. J., Chung, D. J., Schulte, P. M. Tags: RESEARCH ARTICLE Source Type: research

Flight energetics, caste dimorphism and scaling properties in the bumblebee Bombus impatiens [RESEARCH ARTICLE]
Fannie Billardon and Charles-A. Darveau Animal size affects energetics of locomotion. Using female caste dimorphism in bumblebees, we assessed how body mass impacted morphological and physiological traits linked with flight. The allometric relationships obtained for workers wing surface area, wingbeat frequency, flight and resting metabolic rates could predict the trait values of queens that are more than four-fold larger. Flight success of queens decreased over time in part due to a large increase in body mass, and decrease in traits linked with flight, namely wingbeat frequency, metabolic rate, and the activity of metabo...
Source: Journal of Experimental Biology - October 23, 2018 Category: Biology Authors: Billardon, F., Darveau, C.-A. Tags: RESEARCH ARTICLE Source Type: research

Interactions between corticosterone phenotype, environmental stressor pervasiveness and irruptive movement-related survival [RESEARCH ARTICLE]
Tim S. Jessop, Jonathan Webb, Tim Dempster, Benjamin Feit, and Mike Letnic Animals use irruptive movement to avoid exposure to stochastic and pervasive environmental stressors that impact fitness. Beneficial irruptive movements transfer individuals from high-stress areas (conferring low fitness) to alternate localities that may improve survival or reproduction. However, being stochastic, environmental stressors can limit an animal's preparatory capacity to enhance irruptive movement performance. Thus individuals must rely on standing, or rapidly induced, physiological and behavioural responses. Rapid elevation of glucocort...
Source: Journal of Experimental Biology - October 23, 2018 Category: Biology Authors: Jessop, T. S., Webb, J., Dempster, T., Feit, B., Letnic, M. Tags: RESEARCH ARTICLE Source Type: research

Mechanical behavior of shark vertebral centra at biologically relevant strains [RESEARCH ARTICLE]
D. I. Ingle, L. J. Natanson, and M. E. Porter Cartilaginous shark skeletons experience axial deformation at the intervertebral joints, but also within the mineralized cartilaginous centrum, which can compress to between 3 - 8% of its original length in a free-swimming shark. Previous studies have focused on shark centra mechanical properties when loaded to failure, and our goal was to determine properties when compressed to a biologically relevant strain. We selected vertebrae from six shark species and from the anterior and posterior regions of the vertebral column. Centra were x-radiographed to measure double cone propor...
Source: Journal of Experimental Biology - October 23, 2018 Category: Biology Authors: Ingle, D. I., Natanson, L. J., Porter, M. E. Tags: RESEARCH ARTICLE Source Type: research

Scaling of claw sharpness: mechanical constraints reduce attachment performance in larger insects [RESEARCH ARTICLE]
Jonathan G. Pattrick, David Labonte, and Walter Federle Claws are the most widespread attachment devices in animals, but comparatively little is known about the mechanics of claw attachment. A key morphological parameter in determining attachment ability is claw sharpness; however, there is a conflict between sharpness and fracture resistance. Sharper claws can interlock on more surfaces but are more likely to break. Body size interacts with this conflict such that larger animals should have much blunter claws and consequently poorer attachment ability than smaller animals. This expected size-induced reduction in attachmen...
Source: Journal of Experimental Biology - October 23, 2018 Category: Biology Authors: Pattrick, J. G., Labonte, D., Federle, W. Tags: RESEARCH ARTICLE Source Type: research

Measurement and modelling of primary sex ratios for species with temperature-dependent sex determination [RESEARCH ARTICLE]
Melanie D. Massey, Sarah M. Holt, Ronald J. Brooks, and Njal Rollinson For many oviparous animals, incubation temperature influences sex through temperature-dependent sex determination (TSD). Although climate change may skew sex ratios in species with TSD, few available methods predict sex under natural conditions, fewer still are based on mechanistic hypotheses of development, and field tests of existing methods are rare. We propose a new approach that calculates the probability of masculinization (PM) in natural nests. This approach subsumes the mechanistic hypotheses describing the outcome of TSD, by integrating embryon...
Source: Journal of Experimental Biology - October 23, 2018 Category: Biology Authors: Massey, M. D., Holt, S. M., Brooks, R. J., Rollinson, N. Tags: RESEARCH ARTICLE Source Type: research

Water pH limits extracellular but not intracellular pH compensation in the CO2 tolerant freshwater fish, Pangasianodon hypophthalmus [SHORT COMMUNICATION]
Michael A. Sackville, Ryan B. Shartau, Christian Damsgaard, Malthe Hvas, Le My Phuong, Tobias Wang, Mark Bayley, Do Thi Thanh Huong, Nguyen Thanh Phuong, and Colin J. Brauner Preferentially regulating intracellular pH (pHi) confers exceptional CO2 tolerance on fishes, but is often associated with reductions in extracellular pH (pHe) compensation. It is unknown if these reductions are due to intrinsically lower capacities for pHe compensation, hypercarbia-induced reductions in water pH or other factors. To test how water pH affects capacities and strategies for pH compensation, we exposed the CO2 tolerant fish, Pangasianodo...
Source: Journal of Experimental Biology - October 23, 2018 Category: Biology Authors: Sackville, M. A., Shartau, R. B., Damsgaard, C., Hvas, M., Phuong, L. M., Wang, T., Bayley, M., Huong, D. T. T., Phuong, N. T., Brauner, C. J. Tags: SHORT COMMUNICATION Source Type: research

Rafting on floating fruit is effective for oceanic dispersal of flightless weevils [RESEARCH ARTICLE]
This study provides the first empirical evidence that P. jitanasaius larvae can survive ‘rafting’ on ocean currents and that the eggs and larvae of these weevils have the highest probability to cross the oceanic barrier. This ability may facilitate over-the-sea dispersal of these flightless insects and further shape their distribution and speciation pattern in the Western Pacific islands. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 23, 2018 Category: Biology Authors: Yeh, H.-Y., Tseng, H.-Y., Lin, C.-P., Liao, C.-P., Hsu, J.-Y., Huang, W.-S. Tags: RESEARCH ARTICLE Source Type: research

Impact of differences in nutritional quality of wingless and winged aphids on parasitoid fitness [RESEARCH ARTICLE]
Jennifer A.-L. M. Pirotte, Ange Lorenzi, Vincent Foray, and Thierry Hance Winged aphids are described as hosts of lesser quality for parasitoids because a part of their resources is used to produce wings and associated muscles during their development. Host lipid content is particularly important for parasitoid larvae as they lack lipogenesis and therefore rely entirely on the host for this resource. The goal of this study was to determine to what extent winged and wingless aphids differ from a nutritional point of view and whether these differences impact parasitoid fitness, notably the lipid content. We analysed the ene...
Source: Journal of Experimental Biology - October 22, 2018 Category: Biology Authors: Pirotte, J. A.- L. M., Lorenzi, A., Foray, V., Hance, T. Tags: RESEARCH ARTICLE Source Type: research

Dietary antioxidants, but not courtship effort, affect oxidative balance in the testes and muscles of crickets [RESEARCH ARTICLE]
Leigh W. Simmons, Maxine Lovegrove, and Samuel J. Lymbery Recent interest has focused on the role of reactive oxygen species (ROS) as universal constraints in life-history evolution. Empirical studies have examined the oxidative costs of reproduction for females, with little work conducted on males. The male germline is thought to be particularly susceptible to oxidative damage because the testes, and the sperm themselves, can be prolific producers of ROS. We tested the hypothesis that protection of the male germline from oxidative damage represents a cost of reproduction for males. We fed male crickets, Teleogryllus ocea...
Source: Journal of Experimental Biology - October 22, 2018 Category: Biology Authors: Simmons, L. W., Lovegrove, M., Lymbery, S. J. Tags: RESEARCH ARTICLE Source Type: research

Requiem for a heavyweight - can anything more be learned from homing pigeons about the sensory and spatial-representational basis of avian navigation? [COMMENTARY]
Verner P. Bingman The homing pigeon (Columba livia) has long served as a study species to exhaustively investigate the sensory and spatial (map)-representational mechanisms that guide avian navigation. However, several factors have contributed to recent questioning of whether homing pigeons are as valuable as they once were as a general model for the study of the sensory and map-like, spatial-representational mechanisms of avian navigation. These reservations include: the success of this research program in unveiling navigational mechanisms; the burgeoning of new tracking technologies making navigational experiments on lo...
Source: Journal of Experimental Biology - October 22, 2018 Category: Biology Authors: Bingman, V. P. Tags: COMMENTARY Source Type: research

Deciphering function of the pulmonary arterial sphincters in loggerhead sea turtles (Caretta caretta) [RESEARCH ARTICLE]
Daniel Garcia-Parraga, Teresa Lorenzo, Tobias Wang, Jose Luis Ortiz, Joaquin Ortega, Jose Luis Crespo-Picazo, Julio Cortijo, and Andreas Fahlman To provide new insight to the pathophysiological mechanisms underlying gas emboli (GE) in bycaught loggerhead sea turtles (Caretta caretta), the present study investigated the vasoactive characteristics of the pulmonary and systemic arteries, and the lung parenchyma (LP). Tissues were opportunistically excised from recently dead animals for in vitro studies of vasoactive responses to four different neurotransmitters: acetylcholine (ACh, parasympathetic), serotonin (5HT), epinephri...
Source: Journal of Experimental Biology - October 22, 2018 Category: Biology Authors: Garcia-Parraga, D., Lorenzo, T., Wang, T., Ortiz, J. L., Ortega, J., Crespo-Picazo, J. L., Cortijo, J., Fahlman, A. Tags: RESEARCH ARTICLE Source Type: research

Jet-paddling jellies: swimming performance in the Rhizostomeae jellyfish Catostylus mosaicus (Quoy and Gaimard, 1824) [RESEARCH ARTICLE]
Thomas R. Neil and Graham N. Askew Jellyfish are a successful and diverse class of animals that swim via jet propulsion, with swimming performance and propulsive efficiency being related to the animal's feeding ecology and body morphology. The Rhizostomeae jellyfish lack tentacles but possess four oral lobes and eight trailing arms at the centre of their bell, giving them a body morphology quite unlike that of other free-swimming medusae. The implications of this body morphology on the mechanisms by which thrust is produced are unknown. Here we determined the wake structure and propulsive efficiency in the blue-blubber jel...
Source: Journal of Experimental Biology - October 22, 2018 Category: Biology Authors: Neil, T. R., Askew, G. N. Tags: RESEARCH ARTICLE Source Type: research

Using a shell as a wing: pairing of dissimilar appendages in Atlantiid heteropod swimming [SHORT COMMUNICATION]
Ferhat Karakas, Daniel D'Oliveira, Amy E. Maas, and David W. Murphy Atlantiid heteropods are zooplanktonic marine snails which have a calcium carbonate shell and single swimming fin. They actively swim to hunt prey and vertically migrate. Previous accounts of atlantiid heteropod swimming described these animals sculling with the swimming fin while the shell passively hung beneath the body. Here we show, via high speed stereophotogrammetric measurements of body, fin, and shell kinematics, that the atlantiid heteropod Atlanta selvagensis actively flaps both the swimming fin and shell in a highly coordinated wing-like manner ...
Source: Journal of Experimental Biology - October 22, 2018 Category: Biology Authors: Karakas, F., D'Oliveira, D., Maas, A. E., Murphy, D. W. Tags: SHORT COMMUNICATION Source Type: research

Contraction speed and type influences rapid utilisation of available muscle force: neural and contractile mechanisms [RESEARCH ARTICLE]
This study investigated the influence of contraction speed and type on the human ability to rapidly increase torque and utilise the available maximum voluntary torque (MVT) as well as the neuromuscular mechanisms underpinning any effects. Fifteen young, healthy males completed explosive-voluntary knee-extensions in five conditions: isometric (ISO), and both concentric and eccentric at two constant accelerations of 500°.s–2 (CONSLOW and ECCSLOW) and 2000°.s–2 (CONFAST and ECCFAST). Explosive torque and quadriceps EMG were recorded every 25 ms up to 150 ms from their respective onsets and normalised to th...
Source: Journal of Experimental Biology - October 22, 2018 Category: Biology Authors: Tillin, N. A., Pain, M. T. G., Folland, J. P. Tags: RESEARCH ARTICLE Source Type: research

ArHsp40 and ArHsp40-2 contribute to stress tolerance and longevity in Artemia franciscana, but only ArHsp40 influences diapause entry [RESEARCH ARTICLE]
Nathan M. Rowarth and Thomas H. MacRae Embryos of the crustacean Artemia franciscana develop either ovoviviparously or oviparously, yielding swimming larvae (nauplii) or encysted gastrulae (cysts), respectively. Nauplii moult several times and become adults whereas cysts enter diapause, a state of dormancy characterized by exceptionally low metabolism and high stress tolerance. Synthesis of molecular chaperones such as the J-domain proteins ArHsp40 and ArHsp40-2 occurs during embryo development and post-diapause growth of A. franciscana and they influence development and stress tolerance. To further investigate J-domain p...
Source: Journal of Experimental Biology - October 19, 2018 Category: Biology Authors: Rowarth, N. M., MacRae, T. H. Tags: RESEARCH ARTICLE Source Type: research

A new approach for measuring temperature inside turtle eggs [METHODS AND TECHNIQUES]
Boris M. Tezak, Itzel Sifuentes-Romero, and Jeanette Wyneken For turtles, the thermal environment experienced during development plays critical roles in many biological processes. While the temperature inside an egg is assumed to match the substrate temperature, many factors such as evaporative cooling, metabolic heating and the insulating properties of extra-embryonic components can lead to thermal differences. However, no method developed to date has allowed for measurement of the embryonic temperature in live chelonian eggs. We designed a thermocouple-based technique to measure embryonic temperature, achieving 94% surv...
Source: Journal of Experimental Biology - October 19, 2018 Category: Biology Authors: Tezak, B. M., Sifuentes-Romero, I., Wyneken, J. Tags: METHODS AND TECHNIQUES Source Type: research

Environmental temperature alters the digestive performance and gut microbiota of a terrestrial amphibian [RESEARCH ARTICLE]
Samantha S. Fontaine, Alexander J. Novarro, and Kevin D. Kohl Environmental temperature and gut microbial communities can both have profound impacts on the digestive performance of ectothermic vertebrates. Additionally, the diversity, composition and function of gut microbial communities themselves are influenced by temperature. It is typically assumed that the temperature-dependent nature of ectotherm digestive performance is due to factors such as host physiological changes and adaptation to local climatic conditions. However, it is also possible that temperature-induced alterations to gut microbiota may influence the r...
Source: Journal of Experimental Biology - October 19, 2018 Category: Biology Authors: Fontaine, S. S., Novarro, A. J., Kohl, K. D. Tags: RESEARCH ARTICLE Source Type: research

Three-dimensional shape and velocity changes affect responses of a locust visual interneuron to approaching objects [RESEARCH ARTICLE]
Tarquin P. Stott, Erik G. N. Olson, Rachel H. Parkinson, and John R. Gray Adaptive collision avoidance behaviours require accurate detection of complex spatiotemporal properties of an object approaching in an animal's natural, 3-dimensional environment. Within the locust, the lobula giant movement detector (LGMD) and its postsynaptic partner, the descending contralateral movement detector (DCMD) respond robustly to images that emulate an approaching 2-dimensional object and exhibit firing rate modulation correlated with changes in object trajectory. It is not known how this pathway responds to visual expansion of a 3-dimen...
Source: Journal of Experimental Biology - October 19, 2018 Category: Biology Authors: Stott, T. P., Olson, E. G. N., Parkinson, R. H., Gray, J. R. Tags: RESEARCH ARTICLE Source Type: research

Rebel tenrecs disregard hibernation rule book [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 18, 2018 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Extreme physiological plasticity in a hibernating basoendothermic mammal, Tenrec ecaudatus [RESEARCH ARTICLE]
Michael D. Treat, Lori Scholer, Brandon Barrett, Artur Khachatryan, Austin J. McKenna, Tabitha Reyes, Alhan Rezazadeh, Charles F. Ronkon, Dan Samora, Jeremy F. Santamaria, Claudia Silva Rubio, Evan Sutherland, Jeffrey Richardson, John R. B. Lighton, and Frank van Breukelen Physiological plasticity allows organisms to respond to diverse conditions. However, can being too plastic actually be detrimental? Malagasy common tenrecs, Tenrec ecaudatus, have many plesiomorphic traits and may represent a basal placental mammal. We established a laboratory population of T. ecaudatus and found extreme plasticity in thermoregulation a...
Source: Journal of Experimental Biology - October 18, 2018 Category: Biology Authors: Treat, M. D., Scholer, L., Barrett, B., Khachatryan, A., McKenna, A. J., Reyes, T., Rezazadeh, A., Ronkon, C. F., Samora, D., Santamaria, J. F., Silva Rubio, C., Sutherland, E., Richardson, J., Lighton, J. R. B., van Breukelen, F. Tags: RESEARCH ARTICLE Source Type: research

Differences in motor cortical control of the soleus and tibialis anterior [RESEARCH ARTICLE]
This study compared the activity of the primary motor cortex during dynamic plantarflexions and dorsiflexions and compared this with measures obtained during rest. Single- and paired-pulse transcranial magnetic stimulations known as short-interval intracortical inhibition (SICI) were applied to the cortical representation of either the SOL or the TA muscle. The results show that the range of SICI from rest to activity is significantly greater in the TA than in the SOL. Furthermore, when the TA acts as the agonist during dorsiflexions of the ankle, SICI is almost absent (2.9%). When acting as the antagonist during plantarfl...
Source: Journal of Experimental Biology - October 18, 2018 Category: Biology Authors: Lauber, B., Gollhofer, A., Taube, W. Tags: RESEARCH ARTICLE Source Type: research

Vultures respond to challenges of near-ground thermal soaring by varying bank angle [RESEARCH ARTICLE]
Hannah J. Williams, Olivier Duriez, Mark D. Holton, Giacomo Dell'Omo, Rory P. Wilson, and Emily L. C. Shepard Many large birds rely on thermal soaring flight to travel cross-country. As such, they are under selective pressure to minimise the time spent gaining altitude in thermal updrafts. Birds should be able to maximise their climb rates by maintaining a position close to the thermal core through careful selection of bank angle and airspeed, however, there have been few direct measurements of either parameter. Here we apply a novel methodology to quantify the bank angles selected by soaring birds using on-board magnetome...
Source: Journal of Experimental Biology - October 18, 2018 Category: Biology Authors: Williams, H. J., Duriez, O., Holton, M. D., Dell'Omo, G., Wilson, R. P., Shepard, E. L. C. Tags: RESEARCH ARTICLE Source Type: research

High experience levels delay recruitment but promote simultaneous time-memories in honey bee foragers [RESEARCH ARTICLE]
Byron N. Van Nest, Matthew W. Otto, and Darrell Moore Honey bee (Apis mellifera) foragers can remember both the location and time of day food is collected and, even in the absence of a reward, reconnoiter the food source at the appropriate time on subsequent days. This spatiotemporal memory (time-memory) is linked to the circadian clock and enables foragers to synchronize their behavior with floral nectar secretion rhythms, thus eliminating the need to rediscover productive food sources each day. Here, we asked if the establishment of one time-memory influences the formation of another time-memory at the same time of day. ...
Source: Journal of Experimental Biology - October 18, 2018 Category: Biology Authors: Van Nest, B. N., Otto, M. W., Moore, D. Tags: RESEARCH ARTICLE Source Type: research

How do baleen whales stow their filter? A comparative biomechanical analysis of baleen bending [RESEARCH ARTICLE]
Alexander J. Werth, Diego Rita, Michael V. Rosario, Michael J. Moore, and Todd L. Sformo Bowhead and right whale (balaenid) baleen filtering plates, longer in vertical dimension (3-4+ m) than the closed mouth, presumably bend during gape closure. This has not been observed in live whales, even with scrutiny of videorecorded feeding sequences. To determine what happens to baleen as gape closes, we conducted an integrative, multifactorial study including materials testing, functional (flow tank and kinematic) testing, and histological examination. We measured baleen bending properties along the dorsoventral length of plates ...
Source: Journal of Experimental Biology - October 18, 2018 Category: Biology Authors: Werth, A. J., Rita, D., Rosario, M. V., Moore, M. J., Sformo, T. L. Tags: RESEARCH ARTICLE Source Type: research

Glyphosate impairs learning in Aedes aegypti mosquito larvae at field-realistic doses [RESEARCH ARTICLE]
In this study, different groups of larvae were reared in water containing different concentrations of glyphosate that are commonly found in the field (50 µg l–1, 100 µg l–1, 210 µg l–1 and 2 mg l–1). Larvae reared in a glyphosate solution of 2 mg l–1 (application dose) could complete their development. However, glyphosate at a concentration of 100 µg l–1 impaired habituation. A dose-dependent deleterious effect on learning ability was observed. This protocol opens new avenues to further studies aimed at understandi...
Source: Journal of Experimental Biology - October 17, 2018 Category: Biology Authors: Baglan, H., Lazzari, C. R., Guerrieri, F. J. Tags: RESEARCH ARTICLE Source Type: research

Differences in spatial resolution and contrast sensitivity of flight control in the honeybees Apis cerana and Apis mellifera [RESEARCH ARTICLE]
Aravin Chakravarthi, Santosh Rajus, Almut Kelber, Marie Dacke, and Emily Baird Visually guided behaviour is constrained by the capacity of the visual system to resolve detail. This, in turn, is limited by the spatial resolution and contrast sensitivity of the underlying visual system. Because these properties are interdependent and vary non-uniformly, it is only possible to fully understand the limits of a specific visually guided behaviour when they are investigated in combination. To understand the visual limits of flight control in bees, which rely heavily on vision to control flight, and to explore whether they vary b...
Source: Journal of Experimental Biology - October 17, 2018 Category: Biology Authors: Chakravarthi, A., Rajus, S., Kelber, A., Dacke, M., Baird, E. Tags: RESEARCH ARTICLE Source Type: research

Stress does not cause dormouse mums to skip a litter [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Influence of flow on locomotion, feeding behaviour and spatial distribution of a suspension-feeding sea cucumber [RESEARCH ARTICLE]
Jiamin Sun, Jean-Francois Hamel, and Annie Mercier Although movement in response to environmental conditions represents a fundamental link between animal behaviour and population ecology, it is rarely investigated in suspension feeders because they are generally perceived as sessile. Here, the interplay between water flow and fine locomotor and feeding behaviours was experimentally investigated for the first time in a free-moving suspension-feeding sea cucumber (Cucumaria frondosa; Echinodermata, Holothuroidea) using time-lapse videography in a mesocosm setting. Individuals moved away from static conditions in the weakest...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Sun, J., Hamel, J.-F., Mercier, A. Tags: RESEARCH ARTICLE Source Type: research

Tails guard against voracious insects with curtain of breeze [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Context-dependent behavioural lateralization in the European pond turtle, Emys orbicularis (Testudines, Emydidae) [RESEARCH ARTICLE]
Daniele Pellitteri-Rosa and Andrea Gazzola Lateralization presents clear advantages in ecological contexts as the dominance of one brain side prevents the simultaneous activation of contrasting responses in organisms with laterally located eyes. This is crucial in selecting a safe refuge during a predatory attack and may strongly affect predator–prey interactions. We explored the possible presence of lateralization in the anti-predatory behaviour of European pond turtles, considering their escape facing a possible predatory attack. Thirty individuals (17 males, 13 females) were exposed to three different environment...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Pellitteri-Rosa, D., Gazzola, A. Tags: RESEARCH ARTICLE Source Type: research

Adult-larval vibrational communication in paper wasps: the role of abdominal wagging in Polistes dominula [RESEARCH ARTICLE]
Irene Pepiciello, Alessandro Cini, Rachele Nieri, Valerio Mazzoni, and Rita Cervo Communication through vibrational signals is widespread among social insects and regulates crucial social activities. Females of the social wasp Polistes dominula produce substrate-borne vibrations on the combs by performing a conspicuous abdominal oscillatory behavior, known as abdominal wagging. Several studies have reported correlative evidence in support of its signaling role, but direct evidence is still lacking. Because abdominal wagging is strictly associated with the presence of larvae in the nest and with cell inspection, it has bee...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Pepiciello, I., Cini, A., Nieri, R., Mazzoni, V., Cervo, R. Tags: RESEARCH ARTICLE Source Type: research

The insensitive dormouse: reproduction skipping is not caused by chronic stress in Glis glis [RESEARCH ARTICLE]
Jessica S. Cornils, Franz Hoelzl, Nikolaus Huber, Richard Zink, Hanno Gerritsmann, Claudia Bieber, Franz Schwarzenberger, and Thomas Ruf Entire populations of edible dormice (Glis glis) can skip reproduction in years without mast seeding of deciduous trees (particularly beech or oak seed), because juveniles require high-calorie seeds for growth and fattening prior to hibernation. We hypothesized that, in mast failure years, female dormice may be forced to spend larger amounts of time foraging for low-quality food, which would increase their exposure to predators, mainly owls. This may lead to chronic stress, i.e. long-ter...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Cornils, J. S., Hoelzl, F., Huber, N., Zink, R., Gerritsmann, H., Bieber, C., Schwarzenberger, F., Ruf, T. Tags: RESEARCH ARTICLE Source Type: research

Mammals repel mosquitoes with their tails [RESEARCH ARTICLE]
This study may help us determine new mosquito-repelling strategies that do not depend on chemicals. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Matherne, M. E., Cockerill, K., Zhou, Y., Bellamkonda, M., Hu, D. L. Tags: RESEARCH ARTICLE Source Type: research

How the hummingbird wingbeat is tuned for efficient hovering [RESEARCH ARTICLE]
Rivers Ingersoll and David Lentink Both hummingbirds and insects flap their wings to hover. Some insects, like fruit flies, improve efficiency by lifting their body weight equally over the upstroke and downstroke, while utilizing elastic recoil during stroke reversal. It is unclear whether hummingbirds converged on a similar elastic storage solution, because of asymmetries in their lift generation and specialized flight muscle apparatus. The muscles are activated a quarter of a stroke earlier than in larger birds, and contract superfast, which cannot be explained by previous stroke-averaged analyses. We measured the aerod...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Ingersoll, R., Lentink, D. Tags: Comparative biomechanics of movement RESEARCH ARTICLE Source Type: research

Parameters of motion vision in low light in the hawkmoth Manduca sexta [RESEARCH ARTICLE]
Kalyanasundaram Parthasarathy and M. A. Willis The hawkmoth Manduca sexta is nocturnally active, beginning its flight activity at sunset, and executing rapid controlled maneuvers to search for food and mates in dim light conditions. The visual system of this moth has been shown to trade off spatial and temporal resolution for increased sensitivity in these conditions. The study presented here uses tethered flying moths to characterize the flight performance envelope of the wide-field-motion-triggered steering response of M. sexta in low light conditions by measuring attempted turning in response to wide-field visual motio...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Parthasarathy, K., Willis, M. A. Tags: RESEARCH ARTICLE Source Type: research

High accuracy at low frequency: detailed behavioural classification from accelerometer data [RESEARCH ARTICLE]
Jack Tatler, Phillip Cassey, and Thomas A. A. Prowse Accelerometers are a valuable tool for studying animal behaviour and physiology where direct observation is unfeasible. However, giving biological meaning to multivariate acceleration data is challenging. Here, we describe a method that reliably classifies a large number of behaviours using tri-axial accelerometer data collected at the low sampling frequency of 1 Hz, using the dingo (Canis dingo) as an example. We used out-of-sample validation to compare the predictive performance of four commonly used classification models (Random Forest, k-Nearest Neighbour, Support Ve...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Tatler, J., Cassey, P., Prowse, T. A. A. Tags: RESEARCH ARTICLE Source Type: research

Innate visual preferences and behavioral flexibility in Drosophila [RESEARCH ARTICLE]
Martyna J. Grabowska, James Steeves, Julius Alpay, Matthew van de Poll, Deniz Ertekin, and Bruno van Swinderen Visual decision-making in animals is influenced by innate preferences as well as experience. Interaction between hard-wired responses and changing motivational states determines whether a visual stimulus is attractive, aversive, or neutral. It is however difficult to separate the relative contribution of nature versus nurture in experimental paradigms, especially for more complex visual parameters such as the shape of objects. We used a closed-loop virtual reality paradigm for walking Drosophila flies to uncover i...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Grabowska, M. J., Steeves, J., Alpay, J., van de Poll, M., Ertekin, D., van Swinderen, B. Tags: RESEARCH ARTICLE Source Type: research

Glucocorticoid-temperature association is shaped by foraging costs in individual zebra finches [SHORT COMMUNICATION]
Blanca Jimeno, Michaela Hau, and Simon Verhulst Glucocorticoid (GC) levels vary with environmental conditions, but the functional interpretation of GC variation remains contentious. A primary function is thought to be metabolic, mobilizing body reserves to match energetic demands. This view is supported by temperature-dependent GC levels, although reports of this effect show unexplained heterogeneity. We hypothesised that the temperature effect on GC concentrations will depend on food availability through its effect on the energy spent to gather the food needed for thermoregulation. We tested this hypothesis in zebra finch...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Jimeno, B., Hau, M., Verhulst, S. Tags: SHORT COMMUNICATION Source Type: research

Common guillemot (Uria aalge) eggs are not self-cleaning [RESEARCH ARTICLE]
Duncan Jackson, Jamie E. Thompson, Nicola Hemmings, and Timothy R. Birkhead Birds are arguably the most evolutionarily successful extant vertebrate taxon, in part because of their ability to reproduce in virtually all terrestrial habitats. Common guillemots, Uria aalge, incubate their single egg in an unusual and harsh environment; on exposed cliff ledges, without a nest, and in close proximity to conspecifics. As a consequence, the surface of guillemot eggshells is frequently contaminated with faeces, dirt, water and other detritus, which may impede gas exchange or facilitate microbial infection of the developing embryo. ...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Jackson, D., Thompson, J. E., Hemmings, N., Birkhead, T. R. Tags: RESEARCH ARTICLE Source Type: research

Adaptive frequency shifts of echolocation sounds in Miniopterus fuliginosus according to the frequency-modulated pattern of jamming sounds [RESEARCH ARTICLE]
In this study, we examined changes in the acoustic characteristics of pulses emitted by Miniopterus fuliginosus while presenting jamming stimuli with different FM patterns to the bat flying alone. Bats significantly altered their TFs when responding to downward (dEXP) and upward (uEXP) exponential FM sounds as well as to a constant-frequency (CF) stimulus, by approximately 1–2 kHz (dEXP: 2.1±0.9 kHz; uEXP: 1.7±0.3 kHz; CF: 1.3±0.4 kHz) but not for linear FM sounds. The feature common to the spectra of these three jamming stimuli is a spectrum peak near the TF frequency, demonstrating that the bat...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Maitani, Y., Hase, K., Kobayasi, K. I., Hiryu, S. Tags: RESEARCH ARTICLE Source Type: research

Spectral sensitivity in ray-finned fishes: diversity, ecology, and shared descent [RESEARCH ARTICLE]
In this study, we examined phylogenetic, physiological, and ecological patterns of spectral sensitivity of ray-finned fishes (Actinoptergyii) via a meta-analysis of data compiled from 213 species. Across the fishes sampled, our results indicate that trichromacy is most common, ultraviolet max values are not found in monochromatic or dichromatic species, and increasing chromacy, including from tetra- to pentachromacy, significantly increases spectral sensitivity range. In an ecological analysis, multivariate phylogenetic latent liability modeling was performed to analyze correlations between chromacy and five hypothesized p...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: Schweikert, L. E., Fitak, R. R., Caves, E. M., Sutton, T. T., Johnsen, S. Tags: RESEARCH ARTICLE Source Type: research

MicroRNAs regulate survival in oxygen-deprived environments [RESEARCH ARTICLE]
Simon G. English, Hanane Hadj-Moussa, and Kenneth B. Storey Some animals must endure prolonged periods of oxygen deprivation to survive. One such extreme model is the Northern Crayfish (Orconectes virilis), that regularly survives year-round hypoxic and anoxic stresses in its warm stagnant summer waters and in its cold, ice-locked winter waters. To elucidate the molecular underpinnings of anoxia-resistance in this natural model, we surveyed the expression profiles of 76 highly-conserved microRNAs in crayfish hepatopancreas and tail muscle from normoxic, acute 2hr anoxia, and chronic 20hr anoxia exposures. MicroRNAs are kno...
Source: Journal of Experimental Biology - October 15, 2018 Category: Biology Authors: English, S. G., Hadj-Moussa, H., Storey, K. B. Tags: RESEARCH ARTICLE Source Type: research

The engineering of the giant dragonflies of the Permian: revised body mass, power, air supply, thermoregulation and the role of air density [COMMENTARY]
Alan E. R. Cannell An engineering examination of allometric and analogical data on the flight of giant Permian insects (Protodonata, Meganeura or griffinflies) indicates that previous estimates of the body mass of these insects are too low and that the largest of these insects (wingspan of 70 cm or more) would have had a mass of 100–150 g, several times greater than previously thought. Here, the power needed to generate lift and fly at the speeds typical of modern large dragonflies is examined together with the metabolic rate and subsequent heat generated by the thoracic muscles. This evaluation agrees wit...
Source: Journal of Experimental Biology - October 11, 2018 Category: Biology Authors: Cannell, A. E. R. Tags: COMMENTARY Source Type: research

Corticosterone implants produce stress-hyporesponsive birds [RESEARCH ARTICLE]
Fernando Torres-Medina, Sonia Cabezas, Tracy A. Marchant, Martin Wikelski, L. Michael Romero, Michaela Hau, Martina Carrete, Jose L. Tella, and Julio Blas In birds, the use of corticosterone (Cort) implants is a frequent tool aimed at simulating systemic elevations of this hormone and studying effects on biological traits (e.g. physiology, morphology, behavior). This manipulation may alter adrenocortical function, potentially changing both baseline (CortBAS) and stress-induced (CortSTRESS) plasma Cort levels. However, implant effects on the latter trait are rarely measured, disregarding downstream consequences of potentia...
Source: Journal of Experimental Biology - October 11, 2018 Category: Biology Authors: Torres-Medina, F., Cabezas, S., Marchant, T. A., Wikelski, M., Romero, L. M., Hau, M., Carrete, M., Tella, J. L., Blas, J. Tags: RESEARCH ARTICLE Source Type: research

Why cortisol soars in flying squirrels [OUTSIDE JEB]
Sarah Alderman (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 11, 2018 Category: Biology Authors: Alderman, S. Tags: OUTSIDE JEB Source Type: research

Sea bass (can't) smell trouble under elevated CO2 [OUTSIDE JEB]
Molly H. B. Amador (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 11, 2018 Category: Biology Authors: Amador, M. H. B. Tags: OUTSIDE JEB Source Type: research

Ballooning spiders hitch a ride on electric fields [OUTSIDE JEB]
Alex Evans (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 11, 2018 Category: Biology Authors: Evans, A. Tags: OUTSIDE JEB Source Type: research

Risking the land of milk and honey [OUTSIDE JEB]
Julia Nowack (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 11, 2018 Category: Biology Authors: Nowack, J. Tags: OUTSIDE JEB Source Type: research

Great, now the dogs are lying [OUTSIDE JEB]
Matthew D. Regan (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - October 11, 2018 Category: Biology Authors: Regan, M. D. Tags: OUTSIDE JEB Source Type: research