Maternal glucocorticoids have minimal effects on HPA axis activity and behavior of juvenile wild North American red squirrels [RESEARCH ARTICLE]
Sarah E. Westrick, Freya van Kesteren, Stan Boutin, Jeffrey E. Lane, Andrew G. McAdam, and Ben Dantzer As a response to environmental cues, maternal glucocorticoids (GCs) may trigger adaptive developmental plasticity in the physiology and behavior of offspring. In North American red squirrels (Tamiasciurus hudsonicus), mothers exhibit increased GCs when conspecific density is elevated, and selection favors more aggressive and perhaps more active mothers under these conditions. We tested the hypothesis that elevated maternal GCs cause shifts in offspring behavior that may prepare them for high density conditions. We experim...
Source: Journal of Experimental Biology - April 1, 2021 Category: Biology Authors: Westrick, S. E., van Kesteren, F., Boutin, S., Lane, J. E., McAdam, A. G., Dantzer, B. Tags: RESEARCH ARTICLE Source Type: research

Monoterpenoid signals and their transcriptional responses to feeding and juvenile hormone regulations in bark beetle Ips hauseri Reitter [RESEARCH ARTICLE]
Jia Xing Fang, Hui Cong Du, Xia Shi, Su Fang Zhang, Fu Liu, Zhen Zhang, Peng Juan Zu, and Xiang Bo Kong Hauser's engraver beetle Ips hauseri Reitter is a serious pest in spruce forest ecosystems in Central Asia. Its monoterpenoid signal production, transcriptome responses, and potential regulatory mechanisms remain poorly understood. The quality and quantity of volatile metabolites in hindgut extracts of I. hauseri were found to differ between males and females and among three groups: beetles that are newly emerged, those with a topical application of juvenile hormone III (JHIII), and those that have been feeding for 24 h....
Source: Journal of Experimental Biology - April 1, 2021 Category: Biology Authors: Fang, J. X., Du, H. C., Shi, X., Zhang, S. F., Liu, F., Zhang, Z., Zu, P. J., Kong, X. B. Tags: RESEARCH ARTICLE Source Type: research

Beyond the Karman gait: knifefish swimming in periodic and irregular vortex streets [RESEARCH ARTICLE]
Victor M. Ortega-Jimenez and Christopher P. Sanford Neotropical freshwater fishes such as knifefishes are commonly faced with navigating intense and highly unsteady streams. However, our knowledge on locomotion in apteronotids comes from laminar flows, where the ribbon fin dominates over pectoral fins or body bending. Here, we studied the 3D kinematics and swimming control of seven black ghost knifefish (Apteronotus albifrons) moving in laminar flows (flow speed U~1 – 5 Bl/s) and in periodic vortex streets (U~2 – 4 Bl/s). Two different cylinders (~2 and ~3 cm diameter) were used to generate the latter. Addition...
Source: Journal of Experimental Biology - April 1, 2021 Category: Biology Authors: Ortega-Jimenez, V. M., Sanford, C. P. Tags: RESEARCH ARTICLE Source Type: research

Contextual behavioural plasticity in Italian agile frog (Rana latastei) tadpoles exposed to native and alien predator cues [RESEARCH ARTICLE]
Andrea Gazzola, Alessandro Balestrieri, Giovanni Scribano, Andrea Fontana, and Daniele Pellitteri-Rosa Predation is a strong driver for the evolution of prey behaviour. To properly assess the actual risk of predation, anuran tadpoles mostly rely on water-borne chemical cues, and their ability to evaluate environmental information is even more crucial when potential predators consist of unknown alien species. Behavioural plasticity, that is the capacity to express changes in behaviour in response to different environmental stimuli, is crucial to cope with predation risk. We explored the defensive behaviour of Italian agile ...
Source: Journal of Experimental Biology - April 1, 2021 Category: Biology Authors: Gazzola, A., Balestrieri, A., Scribano, G., Fontana, A., Pellitteri-Rosa, D. Tags: RESEARCH ARTICLE Source Type: research

Drosophila larval epidermal cells only exhibit epidermal aging when they persist to the adult stage [RESEARCH ARTICLE]
Yan Wang, Sirisha Burra, and Michael J. Galko Holometabolous insects undergo a complete transformation of the body plan from the larval to the adult stage. In Drosophila, this transformation includes replacement of larval epidermal cells (LECs) by adult epidermal cells (AECs). AECs in Drosophila undergo a rapid and stereotyped aging program where they lose both cell membranes and nuclei. Whether LECs are capable of undergoing aging in a manner similar to AECs remains unknown. Here, we address this question in two ways. First, we looked for hallmarks of epidermal aging in larvae that have a greatly extended third instar and...
Source: Journal of Experimental Biology - April 1, 2021 Category: Biology Authors: Wang, Y., Burra, S., Galko, M. J. Tags: RESEARCH ARTICLE Source Type: research

A thermal stressor, propranolol and LTM formation in freshly collected Lymnaea [RESEARCH ARTICLE]
Cayley Swinton, Erin Swinton, Iain Phillips, and Ken Lukowiak A heat stressor (1h at 30o C) in Lymnaea stagnalis before operant conditioning training of aerial respiration is sufficient to enhance long-term memory (LTM) formation in average cognitive-ability, laboratory-reared, inbred snails. However, in freshly collected outbred snails the same heat stressor blocks LTM formation in smart cognitive phenotype but not in average cognitive phenotype strains. Here we hypothesize that: 1) preventing the stress associated with the heat stressor before training allows LTM to form in the smart phenotype strains ; and 2) alleviatin...
Source: Journal of Experimental Biology - April 1, 2021 Category: Biology Authors: Swinton, C., Swinton, E., Phillips, I., Lukowiak, K. Tags: RESEARCH ARTICLE Source Type: research

Distance estimation by Asian honey bees in two visually different landscapes [SHORT COMMUNICATION]
In this study, we determined the calibration curves of two Asian honey bee species, A. florea and A. cerana, in two different natural environments with clear differences in the vegetation conditions and hence visual contrast. We found that the dense vegetation condition (with higher contrast) elicited a more rapid increase in the waggle phase duration with distance than the sparse vegetation in A. florea but not in A. cerana. Our findings suggest that contrast sensitivity of the waggle dance odometer might vary among honey bee species. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 1, 2021 Category: Biology Authors: George, E. A., Thulasi, N., Kohl, P. L., Suresh, S., Rutschmann, B., Brockmann, A. Tags: SHORT COMMUNICATION Source Type: research

Drosophila acquires seconds-scale rhythmic behavior [RESEARCH ARTICLE]
This study thus not only demonstrated the ability of insects to acquire behavioral rhythms of a few seconds, but highlighted a life-course decline of temporal coordination, that is common also in mammals. (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - April 1, 2021 Category: Biology Authors: Ikarashi, M., Tanimoto, H. Tags: RESEARCH ARTICLE Source Type: research

Hiking trails ideal for sauntering grizzlies [INSIDE JEB]
Kathryn Knight (Source: Journal of Experimental Biology)
Source: Journal of Experimental Biology - March 30, 2021 Category: Biology Authors: Knight, K. Tags: INSIDE JEB Source Type: research

Quantifying energetic costs and defining energy landscapes experienced by grizzly bears [RESEARCH ARTICLE]
Anthony M. Carnahan, Frank T. van Manen, Mark A. Haroldson, Gordon B. Stenhouse, and Charles T. Robbins Animal movements are major determinants of energy expenditure and ultimately the cost–benefit of landscape use. Thus, we sought to understand those costs and how grizzly bears (Ursus arctos) move in mountainous landscapes. We trained captive grizzly bears to walk on a horizontal treadmill and up and down 10% and 20% slopes. The cost of moving upslope increased linearly with speed and slope angle, and this was more costly than moving horizontally. The cost of downslope travel at slower speeds was greater than the c...
Source: Journal of Experimental Biology - March 30, 2021 Category: Biology Authors: Carnahan, A. M., van Manen, F. T., Haroldson, M. A., Stenhouse, G. B., Robbins, C. T. Tags: RESEARCH ARTICLE Source Type: research

Autotomy induced effects on the locomotor performance of the ghost crab, Ocypode quadrata [RESEARCH ARTICLE]
Janne A. Pfeiffenberger and S. Tonia Hsieh The voluntary amputation of an appendage, or autotomy, is an effective defensive mechanism that allows an animal to escape aggressive interactions. However, animals may suffer long-term costs that can reduce their overall fitness. Atlantic ghost crabs (Ocypode quadrata) are one of the fastest terrestrial invertebrates, and regularly lose one or more limbs in response to an antagonist encounter. When running laterally at fast speeds, they adopt a quadrupedal gait using their 1st and 2nd pair of legs while raising their 4th, and sometimes the 3rd, pair of legs off the ground. This s...
Source: Journal of Experimental Biology - March 30, 2021 Category: Biology Authors: Pfeiffenberger, J. A., Hsieh, S. T. Tags: RESEARCH ARTICLE Source Type: research

Archerfish coordinate fin-maneuvers with their shots [RESEARCH ARTICLE]
We describe here that characteristic rapid fin maneuvers, most notably of the pectoral and pelvic fins, are precisely coordinated with the release of the jet. We discovered these maneuvers in two fish that had been trained to shoot from fixed positions at targets in different height, whose jets had been characterized in detail and who remained stable during their shots. Based on the findings in these individuals we examined shooting-associated fin-movement in 28 further archerfish of two species that could shoot from freely chosen positions at targets of different height. Slightly before onset of the water jet, at a time w...
Source: Journal of Experimental Biology - March 30, 2021 Category: Biology Authors: Gerullis, P., Reinel, C. P., Schuster, S. Tags: RESEARCH ARTICLE Source Type: research

Transgenerational plasticity responses of oysters to ocean acidification differ with habitat [RESEARCH ARTICLE]
Laura M. Parker, Elliot Scanes, Wayne A. O'Connor, and Pauline M. Ross Transgenerational plasticity (TGP) has been identified as a critical mechanism of acclimation which may buffer marine organisms against climate change, yet whether the TGP response of marine organisms is altered depending on their habitat is unknown. Many marine organisms are found in intertidal zones where they experience episodes of emersion daily as the tide rises and recedes. During episodes of emersion, the accumulation of metabolic carbon dioxide (CO2) leads to hypercapnia for many species. How this metabolic hypercapnia impacts the TGP response o...
Source: Journal of Experimental Biology - March 30, 2021 Category: Biology Authors: Parker, L. M., Scanes, E., O'Connor, W. A., Ross, P. M. Tags: RESEARCH ARTICLE Source Type: research

Synchrony of complex signals in an acoustically communicating katydid [RESEARCH ARTICLE]
Vivek Nityananda and Rohini Balakrishnan The ability to entrain to auditory stimuli has been a powerful method to investigate the comparative rhythm abilities of different animals. While synchrony to regular simple rhythms is well documented, synchrony to complex stimuli, with multiple components at unequal time intervals, is rarer. Several katydid species with simple calls have been shown to achieve synchrony as part of their natural calling interactions in multi-individual choruses. Yet no study so far has demonstrated synchrony in any insect with a complex call. Using natural calling behaviour and playback experiments, ...
Source: Journal of Experimental Biology - March 30, 2021 Category: Biology Authors: Nityananda, V., Balakrishnan, R. Tags: RESEARCH ARTICLE Source Type: research

Exercise training has morph-specific effects on telomere, body condition and growth dynamics in a color-polymorphic lizard [RESEARCH ARTICLE]
Christopher R. Friesen, Mark Wilson, Nicky Rollings, Joanna Sudyka, Mathieu Giraudeau, Camilla M. Whittington, and Mats Olsson Alternative reproductive tactics (ARTs) are correlated suites of sexually selected traits that are likely to impose differential physiological costs on different individuals. While moderate activity might be beneficial, animals living in the wild often work at the margins of their resources and performance limits. Individuals using ARTs may have divergent capacities for activity. When pushed beyond their respective capacities, they may experience condition loss, oxidative stress, and molecular dama...
Source: Journal of Experimental Biology - March 30, 2021 Category: Biology Authors: Friesen, C. R., Wilson, M., Rollings, N., Sudyka, J., Giraudeau, M., Whittington, C. M., Olsson, M. Tags: RESEARCH ARTICLE Source Type: research