Echolocation and foraging behaviour in the Hawaiian hoary bat, Lasiurus cinereus semotus

1984 ◽  
Vol 62 (11) ◽  
pp. 2113-2120 ◽  
Author(s):  
Jacqueline J. Belwood ◽  
James H. Fullard
Keyword(s):  
Prey Availability ◽  
Weather Conditions ◽  
Peak Frequency ◽  
Social Signals ◽  
Lasiurus Cinereus ◽  
Social Signal ◽  
Term Basis ◽  
Strong Winds ◽  
High Degree ◽  
Lasiurus Cinereus Semotus

Free-flying individual Lasiurus cinereus semotus were observed as they foraged near incandescent lights on the island of Kauai, Hawaii. Two types of vocalizations were recorded from the bats: an echolocation–hunting signal with peak frequency of 27.8 kHz and an agonistic social signal, emitted while the bats were in aggressive pursuit of one another, with a peak frequency of 9.6 kHz. The tendency to vocalize agonistically increased with increased numbers of bats in the foraging area and increased as the density of insects available to the hunting bats decreased. Our observations suggest that the bats may gather echolocation information from their social signals. The bats at the site foraged under most weather conditions, including fog, moderate rain, strong winds, and temperatures as low as 13 °C. Groups of up to eight animals were common, although bats hunted in airspaces that were vigorously defended against other individuals. Small flies and small moths (< 10 mm body length) were the most common insects available as prey, but larger moths (16–20 mm) made up the bulk of the bats' diet. Moths larger than 20 mm were available but not fed on by the bats. This unique study site provides a rare opportunity to compare both prey availability to prey consumption in a population of bats. Our results suggest that this bat, at least on a short-term basis, exhibits a high degree of selectivity in its foraging, a behaviour similar to the mainland subspecies.

scholarly journals Using Social Signals to Predict Shoplifting: A Transparent Approach to a Sensitive Activity Analysis Problem

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6812
Author(s):  
Shane Reid ◽  
Sonya Coleman ◽  
Philip Vance ◽  
Dermot Kerr ◽  
Siobhan O’Neill
Keyword(s):  
Signal Processing ◽  
State Of The Art ◽  
High Accuracy ◽  
Black Box ◽  
Social Signals ◽  
Social Signal Processing ◽  
Legal Cases ◽  
Current State ◽  
Social Signal ◽  
High Degree

Retail shoplifting is one of the most prevalent forms of theft and has accounted for over one billion GBP in losses for UK retailers in 2018. An automated approach to detecting behaviours associated with shoplifting using surveillance footage could help reduce these losses. Until recently, most state-of-the-art vision-based approaches to this problem have relied heavily on the use of black box deep learning models. While these models have been shown to achieve very high accuracy, this lack of understanding on how decisions are made raises concerns about potential bias in the models. This limits the ability of retailers to implement these solutions, as several high-profile legal cases have recently ruled that evidence taken from these black box methods is inadmissible in court. There is an urgent need to develop models which can achieve high accuracy while providing the necessary transparency. One way to alleviate this problem is through the use of social signal processing to add a layer of understanding in the development of transparent models for this task. To this end, we present a social signal processing model for the problem of shoplifting prediction which has been trained and validated using a novel dataset of manually annotated shoplifting videos. The resulting model provides a high degree of understanding and achieves accuracy comparable with current state of the art black box methods.

scholarly journals The effects of flooding and weather conditions on leptospirosis transmission in Thailand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sudarat Chadsuthi ◽  
Karine Chalvet-Monfray ◽  
Anuwat Wiratsudakul ◽  
Charin Modchang
Keyword(s):  
Sensitivity Analysis ◽  
Public Education ◽  
Mathematical Models ◽  
Disease Transmission ◽  
Transmission Rate ◽  
Weather Conditions ◽  
Transmission Dynamics ◽  
Multiplication Rate ◽  
High Degree ◽  
Transmission Models

AbstractThe epidemic of leptospirosis in humans occurs annually in Thailand. In this study, we have developed mathematical models to investigate transmission dynamics between humans, animals, and a contaminated environment. We compared different leptospire transmission models involving flooding and weather conditions, shedding and multiplication rate in a contaminated environment. We found that the model in which the transmission rate depends on both flooding and temperature, best-fits the reported human data on leptospirosis in Thailand. Our results indicate that flooding strongly contributes to disease transmission, where a high degree of flooding leads to a higher number of infected individuals. Sensitivity analysis showed that the transmission rate of leptospires from a contaminated environment was the most important parameter for the total number of human cases. Our results suggest that public education should target people who work in contaminated environments to prevent Leptospira infections.

scholarly journals Manifestation of tip burn on white cabbage hybrids of medium-late and late maturation

2020 ◽  
pp. 84-87
Author(s):  
S. V. Koroleva ◽  
N. B. Shulyak
Keyword(s):  
Weather Conditions ◽  
Calcium Deficiency ◽  
F1 Hybrids ◽  
Experimental Plot ◽  
High Productivity ◽  
White Cabbage ◽  
Sunny Weather ◽  
Degree Of Damage ◽  
Late Maturation ◽  
High Degree

Relevance. The most complex and common physiological disease on the cabbage is a tip burn, associated with impaired Ca2 + transport inside the plant. Of all the ways to control this physiological disease, the most effective is the cultivation of tolerant hybrids. Material and methods.The aim of the research was to evaluate the mid-late and late ripening F1 hybrids of white cabbage for a tip burn and to determine the degree of hybrids responsiveness to calcium deficiency depending on weather conditions. The studies were carried out at breeding and experimental plot of the vegetable growing department at All-Russian Rice Research Institute in 2017-2019 on drip irrigation. Material - hybrid combinations of ARRRI breeding.Results. The manifestation of a physiological disturbance called “burn of the top of the inner leaves of the cabbage head” or “tip burn” on individual hybrids was observed during all years of cultivation, but to a different degree; The greatest damage to the heads was recorded in the years (2017 and 2019) with high productivity, which is due to the intensive assimilation ability against the background of warm sunny weather. In 2019, the manifestation of burns was noted in 25% of hybrids, which allowed them to be divided into 4 groups, depending on the degree of damage and the spread of the disease.It was established that hybrids with overmature standing for 2.5-3 weeks and also hybrids that were promptly removed at the time of mass technical ripeness had a high degree of damage. The lines that are most often found in hybrid combinations with signs of burns (269-824, Agr1321, 269Jas13, Byum112, Yas25, etc.) were identified, but it is rather difficult to assume the nature of inheritance, and, therefore, to develop the principle of pair selection when developing relatively stable hybrids also not yet possible.

Abstract 125: Automated External Defibrillator Shock Advisement Performance Among Multiple Human Electrocardiographic Rhythms and Devices

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Xavier J Szigethy ◽  
Connor J Willson ◽  
David D Salcido ◽  
Dylan A Defilippi ◽  
James J Menegazzi
Keyword(s):  
Sensitivity And Specificity ◽  
Real World ◽  
Peak Frequency ◽  
Lead Wire ◽  
Digital To Analog Converter ◽  
Automated External Defibrillators ◽  
Signal Characteristics ◽  
Rhythm Analysis ◽  
High Degree ◽  
Median Slope

Background: Automated external defibrillators (AEDs) perform rhythm analysis in order to facilitate defibrillation. The effectiveness of AEDs is dependent on the accuracy of their rhythm classification, which includes differentiation of shockable rhythms from non-shockable rhythms Independent (i.e. non-industry) evaluation of the performance of AEDs against real-world ECG could lead to improvements in their performance. Objective: To evaluate the sensitivity and specificity characteristics of commercial AEDs with respect to quantitative properties of the ECG waveform in several rhythm presentations using real world ECG data. Methods: We conducted a prospective simulation study evaluating three commercially available AEDs from Defibtech, Phillips, and Zoll on the determination of ECG rhythm shockability. Performance was evaluated for 181 human ECG recordings (101 ventricular fibrillation-VF, 55 PEA, and 25 asystole) ranging widely in signal characteristics, obtained from the Pittsburgh site of the Resuscitation Outcomes Consortium. We used a commercially available digital-to-analog converter (National Instruments USB-6001) to inject the recordings into each AED through a direct lead-wire interface, recording shock advisement decisions in a best-out-of-three approach for each device/rhythm pairing. We calculated the sensitivity and specificity for discriminating VF and non-VF rhythms for each device and overall. VF signal characteristics were calculated, including peak frequency, median amplitude, and peak amplitude, and the VF quantitative waveform measures AMSA and median slope. Results: The 101 VF trials featured signals with mean peak frequency 10.02 Hz(IQR 4.80 Hz), mean AMSA 9.13(IQR 7.29), mean median slope 6.72 (IQR 3.66). The sensitivities were: Defibtech 99.0%; Philips 97.0%; Zoll 98.0%. The specificities were: Defibtech 98.7%; Philips 96.2%; Zoll 97.4%. Defibtech recorded 5 discordant advisements and Philips and Zoll recorded eight each. The overall sensitivity was 98.0%, and the specificity 97.4%. Conclusion: Evaluated against a wide variety of real-world signal presentations, commercial AEDs demonstrated a high degree of sensitivity and specificity for shockable ECG rhythms.

scholarly journals Impact of climate and moonlight on a venomous mammal, the Javan slow loris (Nycticebus javanicus Geoffroy, 1812)

2014 ◽  
Vol 83 (4) ◽  
pp. 217-225 ◽  
Author(s):  
Eva Johanna Rode-Margono ◽  
K. Anne-Isola Nekaris
Keyword(s):  
Climatic Factors ◽  
Prey Availability ◽  
Interactive Effect ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Activity Level ◽  
Environmental Data ◽  
Foraging Efficiency ◽  
Slow Loris ◽  
Reduce Activity

Predation pressure, food availability, and activity may be affected by level of moonlight and climatic conditions. While many nocturnal mammals reduce activity at high lunar illumination to avoid predators (lunarphobia), most visually-oriented nocturnal primates and birds increase activity in bright nights (lunarphilia) to improve foraging efficiency. Similarly, weather conditions may influence activity level and foraging ability. We examined the response of Javan slow lorises (Nycticebus javanicus Geoffroy, 1812) to moonlight and temperature. We radio-tracked 12 animals in West Java, Indonesia, over 1.5 years, resulting in over 600 hours direct observations. We collected behavioural and environmental data including lunar illumination, number of human observers, and climatic factors, and 185 camera trap nights on potential predators. Nycticebus javanicus reduced active behaviours in bright nights. Although this might be interpreted as a predator avoidance strategy, animals remained active when more observers were present. We did not find the same effect of lunar illumination on two potential predators. We detected an interactive effect of minimum temperature and moonlight, e.g. in bright nights slow lorises only reduce activity when it is cold. Slow lorises also were more active in higher humidity and when it was cloudy, whereas potential predators were equally active across conditions. As slow lorises are well-adapted to avoid/defend predators by crypsis, mimicry and the possession of venom, we argue that lunarphobia may be due to prey availability. In bright nights that are cold, the combined effects of high luminosity and low temperature favour reduced activity and even torpor. We conclude that Javan slow lorises are lunarphobic – just as the majority of mammals.

Long- versus short-range foraging strategies of hoary (Lasiurus cinereus) and silver-haired (Lasionycteris noctivagans) bats and the consequences for prey selection

1985 ◽  
Vol 63 (11) ◽  
pp. 2507-2515 ◽  
Author(s):  
Robert M. R. Barclay
Keyword(s):  
Short Range ◽  
Prey Availability ◽  
Prey Selection ◽  
Foraging Strategy ◽  
Foraging Strategies ◽  
Lasiurus Cinereus ◽  
Echolocation Calls ◽  
Straight Line ◽  
Lasionycteris Noctivagans ◽  
Selection Of

Habitat use, temporal activity, foraging behaviour, and prey selection of hoary bats (Lasiurus cinereus) and silver-haired bats (Lasionycteris noctivagans) were studied at Delta Marsh, Manitoba. Bat activity was assessed by monitoring echolocation calls with ultrasonic detectors. Prey availability was determined using sticky and Malaise traps and dietary information was obtained from fecal analysis. Both species were active all night and foraged primarily in the lee of a narrow forested ridge. Lasionycteris noctivagans foraged in a manner that indicates that it detects and pursues prey over short distances. These bats fly slowly, are highly manoeuverable, and were commonly observed feeding on swarms of insects in small clearings. They use echolocation calls that support the notion of a short-range foraging strategy and feed opportunistically on whatever insects are available. Lasiurus cinereus, on the other hand, uses a long-range prey detection and pursuit foraging strategy. They fly rapidly along straight line paths in open areas and use echolocation calls designed to detect insects at a distance. The diet consists primarily of large insects (moths, beetles, and dragonflies), but the bats nonetheless feed opportunistically. The foraging strategy likely restricts the availability and profitability of small insects as prey.

scholarly journals Mid-winter temperatures, not spring temperatures, predict breeding phenology in the European starling Sturnus vulgaris

2015 ◽  
Vol 2 (1) ◽  
pp. 140301 ◽  
Author(s):  
Tony D. Williams ◽  
Sophie Bourgeon ◽  
Allison Cornell ◽  
Laramie Ferguson ◽  
Melinda Fowler ◽  
...  
Keyword(s):  
Clutch Size ◽  
Prey Availability ◽  
Sturnus Vulgaris ◽  
Winter Temperature ◽  
Laying Date ◽  
Breeding Phenology ◽  
European Starlings ◽  
Winter Temperatures ◽  
Lag Times ◽  
High Degree

In many species, empirical data suggest that temperatures less than 1 month before breeding strongly influence laying date, consistent with predictions that short lag times between cue and response are more reliable, decreasing the chance of mismatch with prey. Here we show in European starlings ( Sturnus vulgaris ) that mid-winter temperature ca 50–90 days before laying (8 January–22 February) strongly ( r 2 = 0.89) predicts annual variation in laying date. Mid-winter temperature also correlated highly with relative clutch size: birds laid later, but laid larger clutches, in years when mid-winter temperatures were lower. Despite a high degree of breeding synchrony (mean laying date 5–13 April = ±4 days; 80% of nests laid within 4.8 days within year), European starlings show strong date-dependent variation in clutch size and productivity, but this appears to be mediated by a different temporal mechanism for integration of supplemental cue (temperature) information. We suggest the relationship between mid-winter temperature and breeding phenology might be indirect with both components correlating with a third factor: temperature-dependent development of the starling's insect (tipulid) prey. Mid-winter temperatures might set the trajectory of growth and final biomass of tipulid larvae, with this temperature cue providing starlings with information on breeding season prey availability (though exactly how remains unknown).

Forecasting for a Remote Island: A Class Exercise

2003 ◽  
Vol 84 (6) ◽  
pp. 777-784 ◽  
Author(s):  
Allen J. Riordan
Keyword(s):  
Research Team ◽  
Weather Conditions ◽  
State University ◽  
Current Output ◽  
North Carolina State University ◽  
Wind Speeds ◽  
Wide Range ◽  
Remote Island ◽  
Satellite Meteorology ◽  
Strong Winds

Students enrolled in a satellite meteorology course at North Carolina State University, Raleigh, recently had an unusual opportunity to apply their forecast skills to predict wind and weather conditions for a remote site in the Southern Hemisphere. For about 40 days starting in early February 2001, students used satellite and model guidance to develop forecasts to support a research team stationed on Bouvet Island (54°26′S, 3°24′E). Internet products together with current output from NCEP's Aviation (AVN) model supported the activity. Wind forecasts were of particular interest to the Bouvet team because violent winds often developed unexpectedly and posed a safety hazard. Results were encouraging in that 24-h wind speed forecasts showed reasonable reliability over a wide range of wind speeds. Forecasts for 48 h showed only marginal skill, however. Two critical events were well forecasted—the major February storm with wind speeds of over 120 kt and a brief calm period following several days of strong winds in early March. The latter forecast proved instrumental in recovering the research team.

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