scholarly journals Bat echolocation calls facilitate social communication

2012 ◽  
Vol 279 (1748) ◽  
pp. 4827-4835 ◽  
Author(s):  
Mirjam Knörnschild ◽  
Kirsten Jung ◽  
Martina Nagy ◽  
Markus Metz ◽  
Elisabeth Kalko
Keyword(s):  
Social Communication ◽  
Social Information ◽  
Individual Identity ◽  
Free Living ◽  
Male And Female ◽  
Echolocation Calls ◽  
Saccopteryx Bilineata ◽  
In The Wild ◽  
Vocal Signatures ◽  
Nocturnal Mammal

Bat echolocation is primarily used for orientation and foraging but also holds great potential for social communication. The communicative function of echolocation calls is still largely unstudied, especially in the wild. Eavesdropping on vocal signatures encoding social information in echolocation calls has not, to our knowledge, been studied in free-living bats so far. We analysed echolocation calls of the polygynous bat Saccopteryx bilineata and found pronounced vocal signatures encoding sex and individual identity. We showed experimentally that free-living males discriminate approaching male and female conspecifics solely based on their echolocation calls. Males always produced aggressive vocalizations when hearing male echolocation calls and courtship vocalizations when hearing female echolocation calls; hence, they responded with complex social vocalizations in the appropriate social context. Our study demonstrates that social information encoded in bat echolocation calls plays a crucial and hitherto underestimated role for eavesdropping conspecifics and thus facilitates social communication in a highly mobile nocturnal mammal.

scholarly journals Socially foraging bats discriminate between group members based on search-phase echolocation calls

2020 ◽  
Vol 31 (5) ◽  
pp. 1103-1112 ◽  
Author(s):  
Jenna E Kohles ◽  
Gerald G Carter ◽  
Rachel A Page ◽  
Dina K N Dechmann
Keyword(s):  
Individual Recognition ◽  
Social Groups ◽  
Social Information ◽  
Individual Identity ◽  
Foraging Success ◽  
Playback Experiments ◽  
Echolocation Calls ◽  
Individual Discrimination ◽  
Group Members ◽  
Molossus Molossus

Abstract Animals have evolved diverse strategies to use social information for increasing foraging success and efficiency. Echolocating bats, for example, can eavesdrop on bats foraging nearby because they shift from search-phase calls to feeding buzzes when they detect prey. Feeding buzzes can directly convey information about prey presence, but it is unknown whether search-phase calls also convey social information. Here, we investigated whether search-phase echolocation calls, distinct calls produced by some bat species to scan large open areas for prey, can additionally convey individual identity. We tested this in Molossus molossus, a neotropical insectivorous bat that forages with group members, presumably to find ephemeral insect swarms more efficiently. We caught M. molossus from six different social groups and recorded their search-phase calls during a standardized release procedure, then recaptured and tested 19 marked bats with habituation–dishabituation playback experiments. We showed that they can discriminate between group members based on search-phase calls, and our statistical analysis of call parameters supported the presence of individual signatures in search-phase calls. Individual discrimination is a prerequisite of individual recognition, which may allow M. molossus to maintain contact with group members while foraging without using specialized signals for communication.

scholarly journals Possible Epigenetic Origin of a Recurrent Gynandromorph Pattern in Megachile Wild Bees

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 437
Author(s):  
Daniele Sommaggio ◽  
Giuseppe Fusco ◽  
Marco Uliana ◽  
Alessandro Minelli
Keyword(s):  
Current Knowledge ◽  
Sex Differentiation ◽  
General Pattern ◽  
Body Parts ◽  
Wild Bees ◽  
Male And Female ◽  
Female Phenotype ◽  
In The Wild ◽  
Gene Transcripts ◽  
Individual Body

Gynandromorphs, i.e., individuals with a mix of male and female traits, are common in the wild bees of the genus Megachile (Hymenoptera, Apoidea). We described new transverse gynandromorphs in Megachile pilidens Alfkeen, 1924 and analyze the spatial distribution of body parts with male vs. female phenotype hitherto recorded in the transverse gynandromorphs of the genus Megachile. We identified 10 different arrangements, nine of which are minor variants of a very general pattern, with a combination of male and female traits largely shared by the gynandromorphs recorded in 20 out of 21 Megachile species in our dataset. Based on the recurrence of the same gynandromorph pattern, the current knowledge on sex determination and sex differentiation in the honey bee, and the results of recent gene-knockdown experiments in these insects, we suggest that these composite phenotypes are possibly epigenetic, rather than genetic, mosaics, with individual body parts of either male or female phenotype according to the locally expressed product of the alternative splicing of sex-determining gene transcripts.

scholarly journals Methods in field chronobiology

2017 ◽  
Vol 372 (1734) ◽  
pp. 20160247 ◽  
Author(s):  
Davide M. Dominoni ◽  
Susanne Åkesson ◽  
Raymond Klaassen ◽  
Kamiel Spoelstra ◽  
Martin Bulla
Keyword(s):  
Technological Development ◽  
Monitoring Systems ◽  
Migratory Restlessness ◽  
Biological Organization ◽  
Rapid Improvement ◽  
Free Living ◽  
The Future ◽  
In The Wild ◽  
Temporal Aspect ◽  
Different Levels

Chronobiological research has seen a continuous development of novel approaches and techniques to measure rhythmicity at different levels of biological organization from locomotor activity (e.g. migratory restlessness) to physiology (e.g. temperature and hormone rhythms, and relatively recently also in genes, proteins and metabolites). However, the methodological advancements in this field have been mostly and sometimes exclusively used only in indoor laboratory settings. In parallel, there has been an unprecedented and rapid improvement in our ability to track animals and their behaviour in the wild. However, while the spatial analysis of tracking data is widespread, its temporal aspect is largely unexplored. Here, we review the tools that are available or have potential to record rhythms in the wild animals with emphasis on currently overlooked approaches and monitoring systems. We then demonstrate, in three question-driven case studies, how the integration of traditional and newer approaches can help answer novel chronobiological questions in free-living animals. Finally, we highlight unresolved issues in field chronobiology that may benefit from technological development in the future. As most of the studies in the field are descriptive, the future challenge lies in applying the diverse technologies to experimental set-ups in the wild. This article is part of the themed issue ‘Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals’.

scholarly journals Changes in African Elephant (Loxodonta africana) faecal steroid concentrations post-defaecation

Bothalia ◽  
2018 ◽  
Vol 48 (1) ◽  
Author(s):  
Judith T. Webber ◽  
Michelle D. Henley ◽  
Yolanda Pretorius ◽  
Michael J. Somers ◽  
Andre Ganswindt
Keyword(s):  
Reproductive Function ◽  
Loxodonta Africana ◽  
African Elephant ◽  
Sample Collection ◽  
Male And Female ◽  
Freeze Dried ◽  
Metabolite Concentrations ◽  
Endocrine Status ◽  
In The Wild ◽  
Sun And Shade

Background: Faecal hormone metabolite measurement is a widely used tool for monitoring reproductive function and response to stressors in wildlife. Despite many advantages of this technique, the delay between defaecation, sample collection and processing may influence steroid concentrations, as faecal bacterial enzymes can alter steroid composition post-defaecation.Objectives: This study investigated changes in faecal glucocorticoid (fGCM), androgen (fAM) and progestagen (fPM) metabolite concentrations in faeces of a male and female African elephant (Loxodonta africana) post-defaecation and the influence of different faeces-drying regimes.Method: Subsamples of fresh faeces were frozen after being dried in direct sun or shade for 6, 20, 24, 48 and 72 h and 7 and 34 days. A subset of samples for each sex was immediately frozen as controls. Faecal hormone metabolite concentrations were determined using enzyme immunoassays established for fGCM, fAM and fPM monitoring in male and female African elephants.Results: Hormone metabolite concentrations of all three steroid classes were stable at first, but changed distinctively after 20 h post-defaecation, with fGCM concentrations decreasing over time and fPM and fAM concentrations steadily increasing. In freeze-dried faeces fGCM concentrations were significantly higher than respective concentrations in sun-dried material, which were in turn significantly higher than fGCM concentrations in shade-dried material. In contrast, fAM concentrations were significantly higher in sun- and shade-dried faeces compared to freeze-dried faeces. Higher fPM concentrations were also found in air-dried samples compared to lyophilised faeces, but the effect was only significant for sun-dried material.Conclusion: The revealed time restriction for collecting faecal material for hormone monitoring from elephants in the wild should be taken into account to assure reliable and comparable results. However, if logistics allow a timely collection, non-invasive hormone measurement remains a powerful and reliable approach to provide information about an elephant’s endocrine status.

How Giraffes Work

2021 ◽  
Author(s):  
Graham Mitchell
Keyword(s):  
Single Species ◽  
Free Living ◽  
Factors Affecting ◽  
Normal Functions ◽  
Private Lives ◽  
Social Biology ◽  
Biochemical Systems ◽  
In The Wild ◽  
Physiological And Biochemical ◽  
Biological Milieu

There are few creatures more beautiful, more aloof, and more fascinating than giraffes. Once they were plentiful and filled African landscapes, but in 2016 they were re-classified from “least concern” to “vulnerable” by the International Union for Conservation of Nature. Their survival in the wild is not assured. Much has been written about their private lives, about their behavior, social biology, and ecology, and their history in art and diplomacy. But so far no book has been written about their private lives, their physiology, and their anatomy and biochemistry—in short, the normal functions of a free-living animal in its natural environment—and it is these aspects of their lives that are the focus of this book. The study of a single species could be concise and relatively simply told. In reality it is not. A species never evolves in isolation from the general biological milieu in which it finds itself. Tectonics, astronomical physics, climate, and purely biological factors affecting food and water resources all shape the path of their evolution and all interact with its morphology, its internal physiological and biochemical systems, and the behavior patterns that regulate its daily life. Giraffes are no exception, as is revealed as the story told here unfolds. How do giraffes work? The answers lie in a story filled not only with the internal workings of a unique creature, but with geography, climate changes of great magnitude, and the labors of extraordinary people who put many pieces of the puzzle together.

scholarly journals Cigarette Smoking Detection with An Inertial Sensor and A Smart Lighter

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 570 ◽  
Author(s):  
Volkan Senyurek ◽  
Masudul Imtiaz ◽  
Prajakta Belsare ◽  
Stephen Tiffany ◽  
Edward Sazonov
Keyword(s):  
Cigarette Smoking ◽  
Inertial Sensor ◽  
Smoking Behavior ◽  
Measurement Unit ◽  
Support Vector ◽  
Svm Classifier ◽  
Free Living ◽  
Objective Monitoring ◽  
In The Wild ◽  
Detection Of Smoking

In recent years, a number of wearable approaches have been introduced for objective monitoring of cigarette smoking based on monitoring of hand gestures, breathing or cigarette lighting events. However, non-reactive, objective and accurate measurement of everyday cigarette consumption in the wild remains a challenge. This study utilizes a wearable sensor system (Personal Automatic Cigarette Tracker 2.0, PACT2.0) and proposes a method that integrates information from an instrumented lighter and a 6-axis Inertial Measurement Unit (IMU) on the wrist for accurate detection of smoking events. The PACT2.0 was utilized in a study of 35 moderate to heavy smokers in both controlled (1.5–2 h) and unconstrained free-living conditions (~24 h). The collected dataset contained approximately 871 h of IMU data, 463 lighting events, and 443 cigarettes. The proposed method identified smoking events from the cigarette lighter data and estimated puff counts by detecting hand-to-mouth gestures (HMG) in the IMU data by a Support Vector Machine (SVM) classifier. The leave-one-subject-out (LOSO) cross-validation on the data from the controlled portion of the study achieved high accuracy and F1-score of smoking event detection and estimation of puff counts (97%/98% and 93%/86%, respectively). The results of validation in free-living demonstrate 84.9% agreement with self-reported cigarettes. These results suggest that an IMU and instrumented lighter may potentially be used in studies of smoking behavior under natural conditions.

scholarly journals Effects of Electromagnetic Fields on the Growth of Nestling American Kestrels

The Condor ◽  
2000 ◽  
Vol 102 (2) ◽  
pp. 461-465 ◽  
Author(s):  
Kimberly J. Fernie ◽  
David M. Bird
Keyword(s):  
Weight Gain ◽  
Electromagnetic Fields ◽  
Transmission Lines ◽  
Bone Growth ◽  
Growth Patterns ◽  
Laboratory Setting ◽  
Male And Female ◽  
Maximal Weight ◽  
American Kestrels ◽  
In The Wild

AbstractWe studied nestling American Kestrels (Falco sparverius) in a laboratory setting to determine whether exposure to electromagnetic fields (EMFs) affected their growth. Captive nestlings were raised by their parents under control or EMF conditions similar to those occurring near transmission lines in the wild. Nestlings also were exposed to EMFs as embryos when incubated by their parents. Measurements of body mass, and lengths of tarsi, antebrachia, and feathers were taken every three days after hatching. EMF exposure affected the growth of female and male nestlings. EMF nestlings and fledglings were heavier and had longer tarsi. The periods of maximal weight gain and antebrachial growth were delayed in EMF males compared to controls, although EMF males were heavier and had similarly long antebrachia to controls by 21 days of age. Growth of ninth primaries and central rectrices of nestlings were unaffected by EMF exposure. Growth patterns of male and female kestrel nestlings were similar to those previously reported for this species, although the periods of maximal weight gain and bone growth did not occur earlier in EMF males than females as it did in controls.

scholarly journals Life cycle of Craspedacusta sowerbyi xinyangensis

2009 ◽  
Vol 55 (3) ◽  
pp. 227-234 ◽  
Author(s):  
Shanliang Xu ◽  
Danli Wang
Keyword(s):  
Life Cycle ◽  
Light Microscopy ◽  
Digital Camera ◽  
Zhejiang Province ◽  
The Other ◽  
Free Living ◽  
Cell Stage ◽  
Germ Layers ◽  
Male And Female ◽  
Gastrovascular Cavity

Abstract To explore the life cycle of Craspedacusta, the authors collected male and female specimens of the Craspedacusta sowerbyi xinyangensis in a small fire-fighting pond in Ningbo, Zhejiang Province in July, 2005 and 2006. The development of C. sowerbyi xinyangensis was studied from zygote to medusa by means of light microscopy and digital camera. The zygotes of C. sowerbyi xinyangensis are globular and smooth (90 - 105 μm diameter) and have an equal, total cleavage to the two-cell stage 15 min after fertilization. The embryos enter the four-cell stage after another 15 min and become multicellular embryos after 3h 15 min. At this stage the embryos have a diameter similar to fertilized eggs but have uneven surfaces that are distinct from the smooth surfaces of the uncleaved zygotes. Solid gastrulae are formed 7 h after fertilization. These are spherical planulae with short surface cilia that begin to swim in slow clockwise circles. After 12 h, they lose their cilia, cease swimming and become elongated planulae with one end larger than the other. Rod-like planulae, similar in thickness at both ends, are formed after an additional 7 h. After 4 days, the planulae develop into tiny polyps having two germ layers and a gastrovascular cavity. The polyp mouth is 50 - 62 µm in diameter, lacking tentacles but having nematocysts around the mouth. Planulae become mature polyps after 10 days (15 days after fertilization). Medusa buds (45 - 88 μm diameter) are formed by polyp budding, which soon become free-living medusae with 8 tentacles (380 - 620 μm diameters). Sometimes, the movement of frustules, which are formed by the polyps and similar to planulae in morphology can also be observed.

scholarly journals Microsporidian Infection in a Free-Living Marine Nematode

2012 ◽  
Vol 11 (12) ◽  
pp. 1544-1551 ◽  
Author(s):  
A. M. Ardila-Garcia ◽  
N. M. Fast
Keyword(s):  
Marine Nematode ◽  
Free Living ◽  
Content Type ◽  
Infection Pattern ◽  
Transmission Electron ◽  
Muscle Tissues ◽  
Natural Hosts ◽  
In The Wild ◽  
Microsporidian Infection

ABSTRACT Microsporidia are unicellular fungi that are obligate endoparasites. Although nematodes are one of the most abundant and diverse animal groups, the only confirmed report of microsporidian infection was that of the “nematode killer” ( Nematocida parisii ). N. parisii was isolated from a wild Caenorhabditis sp. and causes an acute and lethal intestinal infection in a lab strain of Caenorhabditis elegans . We set out to characterize a microsporidian infection in a wild nematode to determine whether the infection pattern of N. parisii in the lab is typical of microsporidian infections in nematodes. We describe a novel microsporidian species named Sporanauta perivermis (marine spore of roundworms) and characterize its infection in its natural host, the free-living marine nematode Odontophora rectangula. S. perivermis is not closely related to N. parisii and differs strikingly in all aspects of infection. Examination by transmission electron microscopy (TEM) revealed that the infection was localized in the hypodermal and muscle tissues only and did not involve the intestines. Fluorescent in situ hybridization (FISH) confirmed infection in the muscle and hypodermis, and surprisingly, it also revealed that the parasite infects O. rectangula eggs, suggesting a vertical mode of transmission. Our observations highlight the importance of studying parasites in their natural hosts and indicate that not all nematode-infecting microsporidia are “nematode killers”; instead, microsporidiosis can be more versatile and chronic in the wild.

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