Fast-moving Animals Research Articles

Chosen Mechanical Properties of Electric Tape Fences

This research is focused on electric tape fencing, particularly of fast-moving animals, especially horses. The mechanical behavior of electric fences is of great importance. On the one hand, the fence should be durable enough, but, on the other hand, it should break if a livestock gets spooked and decides to run through to not cause harm to the animal. Main goal of this study is, therefore, to analyze mechanical properties of different electric tape fences during tensile stress and to propose suitable rheological model useful both for describing mechanical behavior and for predicting properties of electric tape fences. The mechanical behavior of electric fences was examined through two main experimental tests: (a) quasi-static tests to gain the full stress/strain responses of the electric tape in tension and (b) dynamic and stress–relaxation tests to characterize the electric tape fence viscoelasticity. It was found out that strength of electric tape fences is directly dependent on total cross-section area of monofilaments, whereas stiffness coefficients and plasticity limits were also studied. Based on the detailed findings from both types of tension tests, a rheological model of the electric fence was proposed. The results show that the model appropriately describes the experimentally obtained data.

Contrasting coloured ventral wings are a visual collision avoidance signal in birds.

Collisions between fast-moving objects often cause severe damage, but collision avoidance mechanisms of fast-moving animals remain understudied. Particularly, birds can fly fast and often in large groups, raising the question of how individuals avoid in-flight collisions that are potentially lethal. We tested the collision-avoidance hypothesis, which proposes that conspicuously contrasting ventral wings are visual signals that help birds to avoid collisions. We scored the ventral wing contrasts for a global dataset of 1780 bird species. Phylogenetic comparative analyses showed that larger species had more contrasting ventral wings than smaller species, and that in larger species, colonial breeders had more contrasting ventral wings than non-colonial breeders. Evidently, larger species have lower manoeuvrability than smaller species, and colonial-breeding species frequently encounter con- and heterospecifics, increasing their risk of in-flight collisions. Thus, more contrasting ventral wing patterns in these species are a sensory mechanism that facilitates collision avoidance.

New zooarchaeological perspectives on the early Upper Paleolithic Rostamian sequence of Ghar-e Boof (southern Zagros Mountains, Iran)

Ghar-e Boof is a Paleolithic cave site in Iran, known for being the type locality for the early Upper Paleolithic (UP) Rostamian lithic industries. Defining the Rostamian cultural group has significant archaeological implications for the Zagros Mountains. First, it highlights the cultural diversity of the UP in the Zagros. Second, it evinces a more complex scenario for the spread of anatomically modern humans (AMHs) across Southwest Asia. Despite this, little is known about human subsistence strategies during the Rostamian. In this paper, we present the results of a zooarchaeological analysis that allows us to reconstruct prey choice, transport decisions, and carcass processing at Ghar-e Boof. Wild sheep/goat was the main prey at the site, but other taxa such as partridges, tortoises, and gazelles represented important dietary supplements. Mortality data indicate that Rostamian hunters primarily targeted prime-aged adult ungulates. Anatomical representation also shows that there was no selective transport of animal carcasses to the site, so hunting activities most likely took place nearby. Although many specimens in the assemblage were covered by thick concretions, the presence of cut marks demonstrates defleshing, filleting, dismemberment, and even the removal of internal organs of prey. Percussion impacts and cone fractures also suggest the processing of bones for marrow. Chronologically, moving from the oldest to the youngest layers, there is a decrease in large game in parallel with a progressive increase in small, fast-moving animals. Following the prey choice model of optimal foraging theory, this diachronic variation might track regional resource stress or an increase in hunting pressure. Our results, along with the analysis of lithic artifacts and changes in the rates of sedimentation during the Rostamian sequence, indicate an increase in occupation intensity through time. Thus, the archaeological record of Ghar-e Boof and the ubiquity of UP sites across the Dasht-e Rostam region most probably reflect population growth within a few millennia after the arrival of AMHs.

Flying bats use serial sampling to locate odour sources.

Olfactory tracking generally sacrifices speed for sensitivity, but some fast-moving animals appear surprisingly efficient at foraging by smell. Here, we analysed the olfactory tracking strategies of flying bats foraging for fruit. Fruit- and nectar-feeding bats use odour cues to find food despite the sensory challenges derived from fast flight speeds and echolocation. We trained Jamaican fruit-eating bats (Artibeus jamaicensis) to locate an odour reward and reconstructed their flight paths in three-dimensional space. Results confirmed that bats relied upon olfactory cues to locate a reward. Flight paths revealed a combination of odour- and memory-guided search strategies. During ‘inspection flights’, bats significantly reduced flight speeds and flew within approximately 6 cm of possible targets to evaluate the presence or absence of the odour cue. This behaviour combined with echolocation explains how bats maximize foraging efficiency while compensating for trade-offs associated with olfactory detection and locomotion.

A snapping shrimp has the fastest vision of any aquatic animal

Animals use their sensory systems to sample information from their environments. The physiological properties of sensory systems differ, leading animals to perceive their environments in different ways. For example, eyes have different temporal sampling rates, with faster-sampling eyes able to resolve faster-moving scenes. Eyes can also have different dynamic ranges. For every eye, there is a light level below which vision is unreliable because of an insufficient signal-to-noise ratio and a light level above which the photoreceptors are saturated. Here, we report that the eyes of the snapping shrimp Alpheus heterochaelis have a temporal sampling rate of at least 160 Hz, making them the fastest-sampling eyes ever described in an aquatic animal. Fast-sampling eyes help flying animals detect objects moving across their retinas at high angular velocities. A. heterochaelis are fast-moving animals that live in turbid, structurally complex oyster reefs and their fast-sampling eyes, like those of flying animals, may help them detect objects moving rapidly across their retinas. We also report that the eyes of A. heterochaelis have a broad dynamic range that spans conditions from late twilight (approx. 1 lux) to direct sunlight (approx. 100 000 lux), a finding consistent with the circatidal activity patterns of this shallow-dwelling species.

Configurations of home-country experience, leapfrog strategy, and management team composition for acceleration of international expansion: Evidence from Asian multinational enterprises

Asian multinational enterprises (MNEs) are latecomers in the world economy, but some have accelerated their international expansion pace and become significant players in the twenty-first century globalization. This study adopts the set-theoretic approach to explain the acceleration of international expansion among latecomer MNEs. Specifically, this study explores configurations of home-country experience, leapfrog strategy, and management team composition that contribute to some latecomer MNEs’ high acceleration of international expansion. The results suggest seven applicable configurations, reflecting three archetypes of latecomer MNEs that achieve high acceleration of international expansion. We named the three archetypes by employing metaphors of fast-moving animals: (1) newborn tigers, (2) safari lions, and (3) savannah cheetahs, which represent distinctive sub-breeds of latecomer MNEs in the new zoology of the present globalized world. The results offer unique insights into theoretical debates regarding the sufficiency of conventional international business theories for explaining the international expansion of latecomer MNEs.

Optimal foraging, dietary change, and site use during the Paleolithic at Klissoura Cave 1 (southern Greece)

This paper evaluates a long sequence of zooarchaeological remains from Klissoura Cave 1 (southern Greece) within the paradigm of evolutionary ecology. The prey choice, central place foraging, and patch choice models are applied to the dataset in order to understand subsistence shifts related to local resource depression and changes in the intensity of site use from the Middle Paleolithic through Mesolithic. Major trends in prey choice indicate that Middle Paleolithic hominins tended to focus on high-ranked large game resources, while Upper Paleolithic and Mesolithic occupants shifted to lower-ranked small game, fast-moving animals in particular. Overarching shifts in prey use do not correspond to environmental change, so they likely reflect human impacts on local prey populations. Reconstructions of body part profiles indicate that hunters exploited large game animals locally, possibly as they passed through the gorge or drank at a nearby stream. Occupation intensity at the site was highest at the beginning of the Aurignacian, which is reflected by an increase in material culture such as lithics and hearth features, as well as different subsistence strategies. Specifically, bone marrow processing is more important, evidenced by ungulate transport decisions that focus on marrow-rich elements, and an overall increase in marrow processing intensity. Environmental data indicate that conditions in southern Greece were particularly favorable at the beginning of the Aurignacian, which supported rich ungulate faunas and larger populations of their hominin predators in the area. In general, faunal data from Klissoura Cave 1 fit within larger trends found in the Mediterranean over the course of the Late Pleistocene, which indicate that human hunting pressures were on the rise. However, many aspects of prey use are specific to Klissoura Cave 1, reflecting unique environmental and cultural circumstances of southern Greece at various phases in the occupation of the site.

Static antennae act as locomotory guides that compensate for visual motion blur in a diurnal, keen-eyed predator

High visual acuity allows parallel processing of distant environmental features, but only when photons are abundant enough. Diurnal tiger beetles (Carabidae: Cicindelinae) have acute vision for insects and visually pursue prey in open, flat habitats. Their fast running speed causes motion blur that degrades visual contrast, forces stop-and-go pursuit and potentially impairs obstacle detection. We demonstrate here that vision is insufficient for obstacle detection during running, and show instead that antennal touch is both necessary and sufficient for obstacle detection. While running, tiger beetle vision appears to be photon-limited in a way reminiscent of animals in low-light habitats. Such animals often acquire wide-field spatial information through mechanosensation mediated by longer, more mobile appendages. We show that a nocturnal tiger beetle species waves its antennae in elliptical patterns typical of poorly sighted insects. While antennae of diurnal species are also used for mechanosensation, they are rigidly held forward with the tips close to the substrate. This enables timely detection of path obstructions followed by an increase in body pitch to avoid collision. Our results demonstrate adaptive mechanosensory augmentation of blurred visual information during fast locomotion, and suggest that future studies may reveal non-visual sensory compensation in other fast-moving animals.

The origin and evolution of G protein-coupled receptor kinases.

G protein-coupled receptor (GPCR) kinases (GRKs) play key role in homologous desensitization of GPCRs. GRKs phosphorylate activated receptors, promoting high affinity binding of arrestins, which precludes G protein coupling. Direct binding to active GPCRs activates GRKs, so that they selectively phosphorylate only the activated form of the receptor regardless of the accessibility of the substrate peptides within it and their Ser/Thr-containing sequence. Mammalian GRKs were classified into three main lineages, but earlier GRK evolution has not been studied. Here we show that GRKs emerged at the early stages of eukaryotic evolution via an insertion of a kinase similar to ribosomal protein S6 kinase into a loop in RGS domain. GRKs in Metazoa fall into two clades, one including GRK2 and GRK3, and the other consisting of all remaining GRKs, split into GRK1-GRK7 lineage and GRK4-GRK5-GRK6 lineage in vertebrates. One representative of each of the two ancient clades is found as early as placozoan Trichoplax adhaerens. Several protists, two oomycetes and unicellular brown algae have one GRK-like protein, suggesting that the insertion of a kinase domain into the RGS domain preceded the origin of Metazoa. The two GRK families acquired distinct structural units in the N- and C-termini responsible for membrane recruitment and receptor association. Thus, GRKs apparently emerged before animals and rapidly expanded in true Metazoa, most likely due to the need for rapid signalling adjustments in fast-moving animals.

Animal Orientation Strategies for Movement in Flows

For organisms that fly or swim, movement results from the combined effects of the moving medium - air or water - and the organism's own locomotion. For larger organisms, propulsion contributes significantly to progress but the flow usually still provides significant opposition or assistance, or produces lateral displacement ('drift'). Animals show a range of responses to flows, depending on the direction of the flow relative to their preferred direction, the speed of the flow relative to their own self-propelled speed, the incidence of flows in different directions and the proportion of the journey remaining. We here present a classification of responses based on the direction of the resulting movement relative to flow and preferred direction, which is applicable to a range of taxa and environments. The responses adopted in particular circumstances are related to the organisms' locomotory and sensory capacities and the environmental cues available. Advances in biologging technologies and particle tracking models are now providing a wealth of data, which often demonstrate a striking level of convergence in the strategies that very different animals living in very different environments employ when moving in a flow.

Cephalopods Collected by the Submersibles and ROVs of Japan Agency for Marine-Earth Science & Technology-Annotated Catalogue up to 2008-

The crewed submersibles and ROVs of JAMSTEC have obtained many images of nektonic cephalopods, but they only rarely catch voucher specimens of such fast-moving animals. An inventory of JAMSTEC's cephalopod specimens collected by those vehicles yielded nineteen species including some noteworthy species.

Predatory behavior of the land flatworm Notogynaphallia abundans (Platyhelminthes: Tricladida)

Land flatworms are carnivorous, mainly predators. However, knowledge on their predatory behavior and prey preference is very scarce. This paucity of data is a limiting factor in the study of their biology and organismal ecology, resulting in a very difficult task to breed them in the laboratory for prolonged periods if prey preference and predation frequency are unknown. We investigated the predatory behavior of Notogynaphallia abundans (Graff, 1899), Geoplaninae, based on laboratory experiments. In order to determine its predatory choices, we offered mollusks, earthworms, arthropods, and other land flatworms. Only land isopods were accepted, with an average consumption of 3.4 individuals per week. Linear regression showed a positive relationship between the number of consumed isopods and the increase/decrease in body mass. Consumption resulting in an increase in body mass was ca. four isopods per week. Predatory behavior, with a mean time-span of 28 min 45 s ± 15 min 47 s, includes encounter and capture of prey, immobilization, handling and feeding. Variation in the duration of this activity in N. abundans is clearly due to variations in the time necessary for transferring the prey from either the anterior or posterior thirds of the body to the mouth, as well as for external digestion and ingestion. In order to capture very active and fast-moving animals such as land isopods, N. abundans employs various strategies, using either the anterior or the posterior body regions to press the prey against the ground or against its own body, thus allowing it to deal with various responses by the prey, and thereby maximizing predatory success. Similar to other flatworms, both physical holding and entrapment in a mucous secretion are of fundamental importance for prey-immobilization. The different strategies employed by land flatworms in their predatory behavior are discussed, and behavioral plasticity in the capture and immobilization of prey in different platyhelminth groups is emphasized.

Magnetic Tracking of Eye Motion in Small, Fast-Moving Animals

Here, we present a new approach for the magnetic tracking of eye motion in small, fast-moving animals. We employ a thin, flat magnetic tracking transmitter instead of the conventional bulky, cubic-shape transmitting frame. The new transmitter enables convenient access to the tracked animal, causes no visual distractions, and occupies much less space. We also employ a tiny solenoidal search coil instead of the conventional scleral search coils. Such a small solenoidal search coil attached laterally to the eye does not limit the peripheral field of view and allows the animal to perform its standard behavioral tasks. The flat transmitter comprises eight transmitting coils that allow us to monitor not only the orientation of a search coil but also its location. To test the efficiency of the new approach, we have measured the location and orientation of the solenoidal search coils attached to the eyes and head of an archer fish during swimming, targeting, and shooting. The size of the coils attached to the fish eyes was 2 mm in diameter and 2 mm in length, and the size of the coil attached to the fish head was 4 mm in diameter and 4 mm in length. The transmitter size was 60 cm times 60 cm times 2 cm. At a 25 cm from the transmitter, we have obtained the tracking resolution of 3 millidegree and 8.3 mu m rms for a 200-Hz bandwidth. Such a performance is good enough to precisely monitor the fastest component in the fish eyes movements. The fish with the search coils on the eyes and head correctly hits the target up to 20 times during an experimental session, which is similar to the shooting rate of the fish without the search coils. This implies that our new design does not introduce much discomfort for the fish.

Locomotion in terrestrial mammals: the influence of body mass, limb length and bone proportions on speed

Traditionally a few limb proportions or total limb lengths have been regarded as indicative of peak running velocity. This is due to physical principles (inferred in- and outvelocities around the joints, stride lengths) and also the observation that fast-moving animals tend to share a number of purported key features which are either absent or not developed to near the same extent in slower moving forms. Previous studies have shown hind limb length and metatarsus/femur ratio to be correlated significantly, albeit modestly with running speed. These studies have nearly all been bivariate analyses. Based on the physical principles, there is reason to suppose that more variables than just m/f ratio could be important as adaptations for fast locomotion, and also that bivariate analyses are too simple. In this study a sample of 76 running mammals was used, with running speeds taken from literature. A number of osteological parameters were discovered to covary significantly with peak running speed, albeit only modestly. Using the information from phylogeny reduced all correlations, often significantly so. Multivariate analyses resulted in markedly higher correlation coefficients. Animals probably do not optimize their anatomy for the purpose of running very fast, which occurs only on rare occasions, but for reducing costs of locomotion. © 2002 The Linnean Society of London, Zoological Journal of the Linnean Society, 2002, 136, 685–714.

Utilisation of invertebrates discarded from the Nephrops fishery by variously selective benthic scavengers in the west of Scotland

Demersal trawl fisheries generate large quantities of discards which temporarily increase the amount of carrion available to benthic communities and lead to a faster energetic turn- over. This study examines the availability of discarded material to the benthos, assesses consumption times of different items and identifies scavengers attracted to those invertebrates most frequently dis- carded from Clyde Sea Nephrops trawlers. In field and laboratory trials, heavy-shelled dead whelks (Buccinum undatum, Neptunea antiqua) sank faster than softer-bodied species like cephalopods (Allotheuthis subulata, Rossia macrosoma) or echinoderms (Ophiura ophiura, Asterias rubens), mak- ing most discards available to the benthos (at ca. -60 m CD (chart datum)) within minutes after dis- carding. SCUBA and time-lapse camera observations in the Clyde Sea and Loch Sween indicated bait utilisation times between 24 and 48 h. Fast-moving animals like brachyuran crabs were the first to arrive at discard bait piles whose composition mimicked typical discards from the Clyde Sea Nephrops fishery. Bimonthly deployments of traps baited with invertebrate discards in the north of the Clyde Sea showed that A. rubens, followed by Pagurus bernhardus, Liocarcinus depurator and whelks, were the most abundant megafaunal scavengers. Fine-meshed funnel traps deployed inside those creels yielded up to 2819 amphipods per trap, with Scopelocheirus hopei and Orchomene nanus accounting for most of the catch. Together with whelks, A. rubens and Carcinus maenas, O. nanus showed a clear preference for crustacean bait. By contrast, Pagurus bernhardus was more attracted to A. rubens and, in 1 trial, to O. ophiura bait. Traps deployed in the south of the Clyde Sea yielded generally lower numbers and species diversity in the catch, with Nephrops being the most abundant megafaunal scavenger. It showed a preference for L. depurator and conspecific bait. While the results show that a range of epibenthic species readily utilise invertebrates discarded from Clyde Sea Nephrops trawlers, it is unknown to what extent discards subsidise benthic communities as infor- mation on the ecological energetics of the species involved locally is currently lacking.

Tracking of flying insects using pan-tilt cameras

Potent and affordable video and computer systems for automatic data acquisition are becoming increasingly important in behavioural neuroscience. It has remained challenging, however, to acquire data from small and fast-moving animals, such as insects in flight, due to the limited spatial and temporal resolution of the systems currently available. Our research on free-flying insects motivated the development of new methods in the context of two different experimental settings. First, the position and precise body axis direction of honey bees approaching a food source were automatically measured. Second, the flight trajectories of a phonotactic parasitoid fly homing in on its cricket host were recorded in 3D. We used pan-tilt cameras, i.e. cameras with moveable optics, to follow the animal's path with a close up image. Novel methods were developed for image acquisition and position measurement using pan-tilt cameras, as well as calibration and data evaluation in 3D world coordinates. The innovations of this system comprise: (1) Acquisition of images in high spatial detail over large observation areas. (2) Image acquisition at a field rate of 50 Hz PAL. (3) Free positioning of the cameras for 3D acquisition. (4) Computation of the flight path in 3D world coordinates. We illustrate the capabilities of the system with data obtained from a calibration object as well as from the behaviour of unrestricted, free-flying flies and bees. Potential applications in behavioural neuroscience and the psychophysics of sensory perception are briefly discussed.

Using miniature sensor coils for simultaneous measurement of orientation and position of small, fast-moving animals

A system is described that measures, with a sampling frequency of 1 kHz, the orientation and position of a blowfly ( Calliphora vicina) flying in a volume of 0.4×0.4×0.4 m 3. Orientation is measured with a typical accuracy of 0.5°, and position with a typical accuracy of 1 mm. This is accomplished by producing a time-varying magnetic field with three orthogonal pairs of field coils, driven sinusoidally at frequencies of 50, 68, and 86 kHz, respectively. Each pair induces a voltage at the corresponding frequency in each of three miniature orthogonal sensor coils mounted on the animal. The sensor coils are connected via thin (12- μm) wires to a set of nine lock-in amplifiers, each locking to one of the three field frequencies. Two of the pairs of field coils produce approximately homogeneous magnetic fields, which are necessary for reconstructing the orientation of the animal. The third pair produces a gradient field, which is necessary for reconstructing the position of the animal. Both sensor coils and leads are light enough (0.8–1.6 mg for three sensor coils of 40–80 windings, and 6.7 mg/m for the leads, causing a maximal load of approximately 5.7 mg) not to hinder normal flight of the animal (typical weight 80 mg). In general, the system can be used for high-speed recordings of head, eye or limb movements, where a wire connection is possible, but the mechanical load on the moving parts needs to be very small.