Moving in straight lines is a behaviour that enables organisms to search for food, move away from threats, and ultimately seek suitable environments in which to survive and reproduce. This study explores a vision-based technique for detecting a change in heading direction using the Milky Way (MW), one of the navigational cues that are known to be used by night-active insects. An algorithm is proposed that combines the YOLOv8m-seg model and normalised second central moments to calculate the MW orientation angle.
View Article and Find Full Text PDFVespula germanica and Vespula vulgaris are two common European wasps that have ecological and economic importance as a result of their artificial introduction into many different countries and environments. Their success has undoubtedly been aided by their capacity for visually guided hunting, foraging, learning and using visual cues in the context of homing and navigation. However, the visual systems of V.
View Article and Find Full Text PDFMany species rely on celestial cues as a reliable guide for maintaining heading while navigating. In this paper, we propose a method that extracts the Milky Way (MW) shape as an orientation cue in low-light scenarios. We also tested the method on both real and synthetic images and demonstrate that the performance of the method appears to be accurate and reliable to motion blur that might be caused by rotational vibration and stabilisation artefacts.
View Article and Find Full Text PDFThe seasonal migrations of insects involve a substantial displacement of biomass with significant ecological and economic consequences for regions of departure and arrival. Remote sensors have played a pivotal role in revealing the magnitude and general direction of bioflows above 150 m. Nevertheless, the takeoff and descent activity of insects below this height is poorly understood.
View Article and Find Full Text PDFJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
March 2024
The Journal of Comparative Physiology A is the premier peer-reviewed scientific journal in comparative physiology, in particular sensory physiology, neurophysiology, and neuroethology. Founded in 1924 by Karl von Frisch and Alfred Kühn, it celebrates its 100th anniversary in 2024. During these 100 years, many of the landmark achievements in these disciplines were published in this journal.
View Article and Find Full Text PDFThe ability to measure flying insect activity and abundance is important for ecologists, conservationists and agronomists alike. However, existing methods are laborious and produce data with low temporal resolution (e.g.
View Article and Find Full Text PDFFront Insect Sci
September 2023
Introduction: The Bogong moth is well known for its remarkable annual round-trip migration from its breeding grounds across eastern and southern Australia to its aestivation sites in the Australian Alps, to which it provides an important annual influx of nutrients. Over recent years, we have benefited from a growing understanding of the navigational abilities of the Bogong moth. Meanwhile, the population of Bogong moths has been shrinking.
View Article and Find Full Text PDFJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
March 2024
A fateful decision as a 15-year-old high school student, and good advice from a distinguished professor of zoology, were the catalysts that not only decided my entire career but also led me to the Journal of Comparative Physiology A, and to the myriad biological wonders that were held within its covers. In my celebration of JCPA, I look back on the formative years of my career in Australia, and the crucial role that the journal played in shaping my emerging research interests, and ultimately my entire life.
View Article and Find Full Text PDFVertebrates and cephalopods are the two major animal groups that view the world through sophisticated camera-type eyes. There are of course exceptions: nautiloid cephalopods have more simply built pinhole eyes. Excellent camera type eyes are also found in other animals, such as some spider groups, a few snails, and certain marine worms, but the vast majority of large camera-type eyes belong to cephalopods and vertebrates.
View Article and Find Full Text PDFJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
September 2023
In this special issue of articles from leading neuroethologists-all of whom gave outstanding presentations within the Presidential Symposium of the 2022 International Congress of Neuroethology held in Lisbon, Portugal-we learn about the role of cryptochrome molecules in the magnetic sense of animals, how honeybees construct their honeycombs, why fish eyes are built the way they are in species from different depths, how archerfish intercept their newly downed prey with a swift muscular curving of the body (known as a C-start) and how birds process optic flow information to control flight. Each contribution showcases how nervous systems have evolved to control behaviour, the raison d'être of neuroethology.
View Article and Find Full Text PDFJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
September 2023
Eyes in low-light environments typically must balance sensitivity and spatial resolution. Vertebrate eyes with large "pixels" (e.g.
View Article and Find Full Text PDFWe discovered nocturnal colour vision in the Asian giant honeybee a facultatively nocturnal speciesat mesopic light intensities, down to half-moon light levels (approx. 10 cd m). The visual threshold of nocturnality aligns with their reported nocturnal activity down to the same light levels.
View Article and Find Full Text PDFJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
July 2023
Spatial orientation is a prerequisite for most behaviors. In insects, the underlying neural computations take place in the central complex (CX), the brain's navigational center. In this region different streams of sensory information converge to enable context-dependent navigational decisions.
View Article and Find Full Text PDFAll bats possess eyes that are of adaptive value. Echolocating bats have retinae dominated by rod photoreceptors and use dim light vision for navigation, and in rare cases for hunting. However, the visual detection threshold of insectivorous echolocating bats remains unknown.
View Article and Find Full Text PDFJ Comp Physiol A Neuroethol Sens Neural Behav Physiol
May 2023
During the 99 years of its history, the Journal of Comparative Physiology A has published many of the most influential papers in comparative physiology and related disciplines. To celebrate this achievement of the journal's authors, annual Editors' Choice Awards and Readers' Choice Awards are presented. The winners of the 2023 Editors' Choice Awards are 'Contact chemoreception in multi‑modal sensing of prey by Octopus' by Buresch et al.
View Article and Find Full Text PDFThe ability to see colour at night is known only from a handful of animals. First discovered in the elephant hawk moth , nocturnal colour vision is now known from two other species of hawk moths, a single species of carpenter bee, a nocturnal gecko and two species of anurans. The reason for this rarity-particularly in vertebrates-is the immense challenge of achieving a sufficient visual signal-to-noise ratio to support colour discrimination in dim light.
View Article and Find Full Text PDFGiant honeybees, including the open-nesting Asian giant honeybee Apis dorsata, display a spectacular collective defence behaviour - known as 'shimmering' - against predators, which is characterised by travelling waves generated by individual bees flipping their abdomens in a coordinated and sequential manner across the bee curtain. We examined whether shimmering is visually mediated by presenting moving stimuli of varying sizes and contrasts to the background (dark or light) in bright and dim ambient light conditions. Shimmering was strongest under bright ambient light, and its strength declined under dim light in this facultatively nocturnal bee.
View Article and Find Full Text PDFThere are hundreds of thousands of moth species with crucial ecological roles that are often obscured by their nocturnal lifestyles. The pigmentation and appearance of moths are dominated by cryptic diffuse shades of brown. In this study, 82 specimens representing 26 moth species were analysed using infrared polarimetric hyperspectral imaging in the range of 0.
View Article and Find Full Text PDFFor navigation, animals use a robust internal compass. Compass navigation is crucial for long-distance migrating animals like monarch butterflies, which use the sun to navigate over 4,000 km to their overwintering sites every fall. Sun-compass neurons of the central complex have only been recorded in immobile butterflies, and experimental evidence for encoding the animal's heading in these neurons is still missing.
View Article and Find Full Text PDFRecent interest in applying novel imaging techniques to infer optical resolution in compound eyes underscores the difficulty of obtaining direct measures of acuity. A widely used technique exploits the principal pseudopupil, a dark spot on the eye surface representing the ommatidial gaze direction and the number of detector units (ommatidia) viewing that gaze direction. However, dark-pigmented eyes, like those of honeybees, lack a visible pseudopupil.
View Article and Find Full Text PDFInsect neuroscience generates vast amounts of highly diverse data, of which only a small fraction are findable, accessible and reusable. To promote an open data culture, we have therefore developed the InsectBrainDatabase (), a free online platform for insect neuroanatomical and functional data. The facilitates biological insight by enabling effective cross-species comparisons, by linking neural structure with function, and by serving as general information hub for insect neuroscience.
View Article and Find Full Text PDFStudying the routes flown by long-distance migratory insects comes with the obvious challenge that the animal's body size and weight is comparably low. This makes it difficult to attach relatively heavy transmitters to these insects in order to monitor their migratory routes (as has been done for instance in several species of migratory birds. However, the rather delicate anatomy of insects can be advantageous for testing their capacity to orient with respect to putative compass cues during indoor experiments under controlled conditions.
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