scholarly journals Effects of Group Behavior in The Predatory Raid on Damselfish Nests By The False Cleanerfish Aspidontus Taeniatus

2021 ◽  
Author(s):  
Hajime Sato ◽  
Yoichi Sakai ◽  
Tetsuo Kuwamura
Keyword(s):  
Dilution Effect ◽  
Field Studies ◽  
Group Behavior ◽  
Foraging Efficiency ◽  
Field Observations ◽  
Labroides Dimidiatus ◽  
Feeding Groups ◽  
Cooperative Foraging ◽  
Egg Guarding ◽  
Fish Fins

Abstract The benefits of group behavior have been reported in a variety of animals. The false cleanerfish Aspidontus taeniatus, which resembles the bluestreak cleaner wrasse Labroides dimidiatus, is the best-known example of mimicry in vertebrates. This mimicry system has been viewed as an aggressive mimicry to bite fish fins. However, recent field studies have reported that large individuals of the false cleanerfish form groups and jointly raid fish nests to eat eggs that are guarded by their parents. Since the cleaner wrasse does not form such groups or specialize in egg-eating, the feeding groups of the false cleanerfish is assumed to reduce the effectiveness of mimicry. Here, we conducted field observations to clarify the functions of group behavior in egg-eating in the false cleanerfish. The false cleanerfish formed groups of 2–12 individuals when they raided breeding nests of 13 damselfish (Pomacentridae) and one triggerfish (Balistidae). The results showed that the group behavior has two effects: a dilution effect, which reduces the risk of being attacked by egg-guarding fish, and an increase in foraging efficiency. We conclude that the false cleanerfish need to form cooperative foraging groups during egg-eating because the egg-guarding parents could see through the mimicry.

Field Observations on Group Compositions in the Agile Wallaby, Macropus agilis (Gould) (Marsupialia : Macropodidae)

1980 ◽  
Vol 7 (3) ◽  
pp. 327 ◽  
Author(s):  
PM Johnson
Keyword(s):  
Short Duration ◽  
Field Studies ◽  
Field Observations ◽  
Short Supply ◽  
Male And Female ◽  
Feeding Groups ◽  
Group Compositions ◽  
The Relationship

Group compositions of agile wallabies were recorded during field studies in north Queensland. Single individuals were the most commonly observed 'group', which suggests an essentially solitary nature. Groups of more than four were feeding groups, seen mainly when food was in short supply. The relationship between a female and its young was of short duration, and the sexual association between male and female was transient.

scholarly journals Methods of calculating landslide volume using remote sensing data

2020 ◽  
Vol 149 ◽  
pp. 02009
Author(s):  
Maira Razakova ◽  
Alexandr Kuzmin ◽  
Igor Fedorov ◽  
Rustam Yergaliev ◽  
Zharas Ainakulov
Keyword(s):  
Remote Sensing ◽  
Sea Level ◽  
Remote Sensing Data ◽  
Field Studies ◽  
Aerial Photographs ◽  
Field Observations ◽  
Sensing Data ◽  
Quantitative Estimates ◽  
Landslide Volume ◽  
Engineering Protection

The paper considers the issues of calculating the volume of the landslide from remote sensing data. The main methods of obtaining information during research are field observations. The most important results of field studies are quantitative estimates, such as the volume of the embankment resulting from a landslide, morphometric indicators, etc. The study of a remote and remote object was carried out by remote methods using aerial photographs in the Ile Alatau foothills at 1,600 meters above sea level. The obtained materials from the mudflow survey will be useful in developing solutions to mitigate the effects of disasters and in the design of measures for engineering protection from landslides.

Towards a process-based model to predict dune erosion along the Dutch Wadden coast

2012 ◽  
Vol 91 (3) ◽  
pp. 357-372 ◽  
Author(s):  
B.G. Ruessink ◽  
M. Boers ◽  
P.F.C. van Geer ◽  
A.T.M. de Bakker ◽  
A. Pieterse ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Current Knowledge ◽  
Numerical Models ◽  
Field Studies ◽  
Breaking Waves ◽  
Sand Transport ◽  
Breaking Wave ◽  
Field Observations ◽  
Erosion Model ◽  
Dune Erosion

AbstractAn equilibrium dune-erosion model is used every six years to assess the capability of the most seaward dune row on the Dutch Wadden islands to withstand a storm with a 1 in 10,000 probability for a given year. The present-day model is the culmination of numerous laboratory experiments with an initial cross-shore profile based on the central Netherlands coast. Large parts of the dune coast of the Wadden islands have substantially different dune and cross-shore profile characteristics than found along this central coast, related to the presence of tidal channels, ebb-tidal deltas, beach-plains and strong coastal curvature. This complicated coastal setting implies that the predictions of the dune-erosion model are sometimes doubtful; accordingly, a shift towards a process-based dune-erosion model has been proposed. A number of research findings based on recent laboratory and field studies highlight only few of the many challenges that need to be faced in order to develop and test such a model. Observations of turbulence beneath breaking waves indicate the need to include breaking-wave effects in sand transport equations, while current knowledge of infragravity waves, one of the main sand transporting mechanisms during severe storm conditions, is strongly challenged by laboratory and field observations on gently sloping beaches that are so typical of the Wadden islands. We argue that in-situ and remote-sensing field observations, laboratory experiments and numerical models need to be the pillars of Earth Scientific research in the Wadden Sea area to construct a meaningful process-based dune-erosion tool.

scholarly journals The benefit of being a social butterfly: communal roosting deters predation

2012 ◽  
Vol 279 (1739) ◽  
pp. 2769-2776 ◽  
Author(s):  
Susan D. Finkbeiner ◽  
Adriana D. Briscoe ◽  
Robert D. Reed
Keyword(s):  
Information Sharing ◽  
Selective Pressure ◽  
Dilution Effect ◽  
Field Studies ◽  
Attack Frequency ◽  
Adaptive Value ◽  
Aggregation Size ◽  
Communal Roosting ◽  
Predator Defence ◽  
Unpalatable Prey

Aposematic passion-vine butterflies from the genus Heliconius form communal roosts on a nightly basis. This behaviour has been hypothesized to be beneficial in terms of information sharing and/or anti-predator defence. To better understand the adaptive value of communal roosting, we tested these two hypotheses in field studies. The information-sharing hypothesis was addressed by examining following behaviour of butterflies departing from natural roosts. We found no evidence of roost mates following one another to resources, thus providing no support for this hypothesis. The anti-predator defence hypothesis was tested using avian-indiscriminable Heliconius erato models placed singly and in aggregations at field sites. A significantly higher number of predation attempts were observed on solitary models versus aggregations of models. This relationship between aggregation size and attack rate suggests that communally roosting butterflies enjoy the benefits of both overall decreased attack frequency as well as a prey dilution effect. Communal roosts probably deter predators through collective aposematism in which aggregations of conspicuous, unpalatable prey communicate a more effective repel signal to predators. On the basis of our results, we propose that predation by birds is a key selective pressure maintaining Heliconius communal roosting behaviour.

scholarly journals Social interactions drive efficient foraging and income equality in groups of fish

2019 ◽  
Author(s):  
Roy Harpaz ◽  
Elad Schneidman
Keyword(s):  
Social Interactions ◽  
Interaction Mechanism ◽  
Group Behavior ◽  
Food Distribution ◽  
Foraging Efficiency ◽  
Mechanistic Models ◽  
Adult Zebrafish ◽  
Group Foraging ◽  
Income Equality ◽  
The Social

AbstractThe social interactions underlying group foraging and their benefits have been mostly studied using mechanistic models replicating qualitative features of group behavior, and focused on a single resource or a few clustered ones. Here, we tracked groups of freely foraging adult zebrafish with spatially dispersed food items and found that fish perform stereotypical maneuvers when consuming food, which attract neighboring fish. We then present a mathematical model, based on inferred functional interactions between fish, which accurately describes individual and group foraging of real fish. We show that these interactions allow fish to combine individual and social information to achieve near-optimal foraging efficiency and promote income equality within groups. We further show that the interactions that would maximize efficiency in these social foraging models depend on group size, but not on food distribution - suggesting that fish may adaptively pick the subgroup of neighbors they “listen to” to determine their own behavior.Impact statementAnalysis and modeling of group behavior of adult zebrafish shows that a specialized social interaction mechanism increases foraging efficiency and equality within groups, under a variety of environmental conditions.

scholarly journals Observing the Observers: Researching Surveillance and Counter-Surveillance on 'Skid Row'

2002 ◽  
Vol 3 (2/3) ◽  
Author(s):  
Thomas Kemple ◽  
Laura Huey
Keyword(s):  
Field Studies ◽  
Urban Spaces ◽  
Broken Windows ◽  
Field Observations ◽  
Skid Row ◽  
Ethical Problems ◽  
Surveillance Studies ◽  
Ethical Implications ◽  
Community Stakeholders ◽  
Field Notes

Using empirical research drawn from field studies on the policing of 'skid row' communities, this paper illustrates some of the theoretical, methodological and ethical problems that confront the researcher who studies surveillance and counter-surveillance within these contested settings. We begin by noting how, with the increasing use of the 'broken windows' policing model to regulate deviant individuals and to secure derelict urban spaces, researchers may be implicated in the use of surveillance and counter-surveillance by community stakeholders. Drawing examples from direct and covert field observations, field notes, and photographs, we demonstrate that there is a significant potential for the researcher to become identified as an agent of surveillance, and as a potential target of counter-surveillance, within such settings. We conclude by considering some of the theoretical, methodological and ethical implications of the researcher's complicity in these dynamics for both the conduct of surveillance studies in general, and for urban fieldwork in particular.

MCPA Synergizes Imazamox Control of Feral Rye (Secale cereale)

2011 ◽  
Vol 25 (3) ◽  
pp. 303-309 ◽  
Author(s):  
Andrew R. Kniss ◽  
Drew J. Lyon ◽  
Joseph D. Vassios ◽  
Scott J. Nissen
Keyword(s):  
Ammonium Phosphate ◽  
Dry Weight ◽  
Field Studies ◽  
Field Observations ◽  
Laboratory Studies ◽  
Fertilizer Rate ◽  
Initial Field ◽  
Spray Solution ◽  
Treated Leaf ◽  
Feral Rye

Field, greenhouse, and laboratory studies were conducted to determine the effect of MCPA ester, fertilizer type, and fertilizer rate on feral rye control with imazamox. In field studies near Sidney, NE, increasing the concentration of liquid ammonium phosphate (10–34–0) from 2.5 to 50% of the spray solution decreased feral rye control with imazamox by as much as 73%. Conversely, adding MCPA ester to imazamox significantly increased feral rye control in field studies by up to 77%. Initial greenhouse studies confirmed the liquid ammonium phosphate antagonism effect, but subsequent greenhouse studies were inconsistent with regard to the interaction between fertilizer and imazamox. At least one source of liquid ammonium phosphate was shown not to be antagonistic, and therefore fertilizer source or contaminants may be responsible for initial field observations. Greenhouse studies confirmed the synergistic interaction between MCPA and imazamox. MCPA ester applied at 560 g ai ha−1 decreased the rate of imazamox required to cause 50% reduction in feral rye dry weight (GR50) to 13 g ha−1 compared to 35 g ha−1 for imazamox alone. Although addition of MCPA ester increased 14C-imazamox absorption by 8% in laboratory studies, less 14C translocated out of the treated leaf; therefore the mechanism of synergism does not appear to be related to imazamox absorption or translocation.

Full-scale field studies of the dynamic response of piles embedded in partially frozen soils

1991 ◽  
Vol 28 (5) ◽  
pp. 708-718 ◽  
Author(s):  
Hans Vaziri ◽  
Yingcai Han
Keyword(s):  
Dynamic Response ◽  
Soil Layer ◽  
Field Measurements ◽  
Field Studies ◽  
Full Scale ◽  
Frozen Soil ◽  
Field Observations ◽  
Practical Applications ◽  
Order Of Magnitude ◽  
Full Scale Tests

The influence of a frozen soil layer on the dynamic response of full-scale concrete piles subjected to strong horizontal excitation was studied. The study undertaken compares the field observations against the theoretical predictions and provides an insight into the role of the yielded zone (boundary zone) in theoretically matching the field observations. The field measurements are used to postulate empirical relationships that can be used under practical conditions to estimate the magnitude of soil separation around piles embedded in cohesive soils as a function of the maximum vibration amplitude. The tests performed indicate that the presence of a frozen soil layer, even at a modest thickness of less than 0.5 m, can significantly influence the dynamic response of piles; the horizontal stiffness of the pile was increased by one order of magnitude, and its resonant frequency was increased by a factor of four compared to the situation with no frozen soil layer. The qualitative and quantitative findings from this study are considered to have practical applications in the design of piles under similar conditions as well as in providing a field validation of the theoretical solutions that have been developed for analyzing the dynamic response of piles. Key words: dynamics, vibration, piles, full-scale tests, frozen soil, modelling, resonance, soil separation, soil yielding.

scholarly journals Effects of Tissue Preservation on Carbon and Nitrogen Stable Isotope Signatures in Syngnathid Fishes and Prey

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2301
Author(s):  
Miquel Planas ◽  
Alex Paltrinieri ◽  
Mario Davi Dias Carneiro ◽  
Jorge Hernández-Urcera
Keyword(s):  
Isotopic Analysis ◽  
Field Studies ◽  
Regression Equations ◽  
Δ13c And Δ15n ◽  
Carbon And Nitrogen ◽  
Historical Collections ◽  
Preservation Methods ◽  
Isotopic Studies ◽  
Different Types ◽  
Fish Fins

Isotopic stable analysis (SIA) is a powerful tool in the assessment of different types of ecological and physiological studies. For that, different preservation methods for sampled materials are commonly used prior to isotopic analysis. The effects of various preservation methods (freezing, ethanol and formaldehyde) were analyzed for C:N, and δ13C and δ15N signals on a variety of tissues including dorsal fins (three seahorse and two pipefish species), seahorse newborns (three seahorses species), and prey (copepods and different stages of Artemia) commonly used to feed the fishes under rearing conditions. The aims of the study were: (i) to evaluate isotopic effects of chemical preservation methods across different types of organisms and tissues, using frozen samples as controls, and (ii) to construct the first conversion models available in syngnathid fishes. The chemical preservation in ethanol and, to a lesser extent, in formaldehyde significantly affected δ13C values, whereas the effects on δ15N signatures were negligible. Due to their low lipid content, the isotopic signals in fish fins was almost unaffected, supporting the suitability of dorsal fins as the most convenient material in isotopic studies on vulnerable species such as syngnathids. The regression equations provided resulted convenient for the successful conversion of δ13C between preservation treatments. Our results indicate that the normalization of δ15N signatures in preserved samples is unnecessary. The conversion models should be applicable in isotopic field studies, laboratory experiments, and specimens of historical collections.

scholarly journals Analisis dan Perancangan Aplikasi Bee-Messenger Sebagai Media-Media Instant Messanging di Universitas Bina Nusantara

2010 ◽  
Vol 1 (2) ◽  
pp. 1097
Author(s):  
Eddy Santosa Jaya ◽  
Irawan Irawan ◽  
Regan Regan ◽  
Indahwati Indahwati
Keyword(s):  
Communication Technology ◽  
Instant Messaging ◽  
Low Cost ◽  
Field Studies ◽  
The Internet ◽  
Field Observations ◽  
Rapid Rate ◽  
Practical Application ◽  
Single Application ◽  
Msn Messenger

Technology today has progressed at a rapid rate, as well as with instant messaging growing into all aspects of life, even more so in the advancement of communication technology. By using the VoIP feature, users can communicate by voice via the Internet. Messenger as a communication medium that is fast, accurate and low cost is expected to meet the need for a practical communication media. The purpose of this study is to analyze and design a messaging application called Bee-Messenger which will be used as a medium of instant messaging in Bina Nusantara University, and also analyze the needs of users with feature-contained in commonly used messenger applications. Research methods used are literature review, field studies, and field observations. Evaluation is based on the comparison of Bee-Messenger features with the same features found in Yahoo Messenger and MSN Messenger. Bee-Messenger can also activate YM and MSN messaging accounts simultaneously in a single application that gives users a practical application messaging. 

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