Variation in the echolocation calls of the hoary bat (Lasiurus cinereus): influence of body size, habitat structure, and geographic location

1999 ◽  
Vol 77 (4) ◽  
pp. 530-534 ◽  
Author(s):  
Robert MR Barclay ◽  
James H Fullard ◽  
David S Jacobs
Keyword(s):  
Visual Information ◽  
Habitat Type ◽  
Geographic Location ◽  
Encounter Rate ◽  
Echolocation Call ◽  
Lasiurus Cinereus ◽  
Echolocation Calls ◽  
Hoary Bat ◽  
The Individual ◽  
Rule Out

The echolocation calls of bats vary according to the task being undertaken by the individual. Within species, there is evidence for geographic, habitat, and individual variation, although it is often difficult to separate these factors and rule out variation in recording or analysis techniques. We studied the variation in echolocation call design of the hoary bat (Lasiurus cinereus) by analyzing calls, recorded in the same manner, from free-flying bats at one site in Manitoba and at four sites in the Hawaiian islands. Sites varied in terms of the proximity of the bats to vegetation. As predicted, individuals from the larger subspecies (Lasiurus cinereus cinereus; Manitoba) used lower frequency calls than did the smaller individuals in Hawaii. Within the same habitat type (open or closed), there was evidence for differences in echolocation call design between populations on different islands. On the island of Hawaii, bats at a single site used shorter higher frequency calls when foraging within the vegetation than when foraging in the open, again as predicted. However, bats foraging in different sites used calls with the opposite characteristics to those predicted on the basis of the openness of the site. Although there are several possible explanations for this, we suggest that prey encounter rate and the ability of bats to augment acoustic prey detection with visual information may be important.

The diet of the insectivorous Hawaiian hoary bat (Lasiurus cinereus semotus) in an open and a cluttered habitat

1999 ◽  
Vol 77 (10) ◽  
pp. 1603-1608 ◽  
Author(s):  
David S Jacobs
Keyword(s):  
Foraging Strategy ◽  
Foraging Efficiency ◽  
Insect Fauna ◽  
Detection Range ◽  
Lasiurus Cinereus ◽  
Echolocation Calls ◽  
Insect Prey ◽  
Open Habitat ◽  
Hoary Bat ◽  
Lasiurus Cinereus Semotus

The Hawaiian hoary bat, Lasiurus cinereus semotus, foraged in both an open and a cluttered habitat. In the cluttered habitat it used slow, manoeuvring flight. In the open habitat it used rapid, less manoeuvring flight with echolocation calls of higher frequency than in the cluttered habitat. The combination of faster flight with higher frequency echolocation calls means that it should detect insect prey too late to manoeuvre for capture unless it preyed on relatively larger insects in the open habitat. The mean size of dietary items should therefore be greater in the open habitat than in the cluttered habitat. There should also be a greater preponderance of larger insects in the open than in the cluttered habitat to ensure that the use of rapid flight with higher frequency echolocation calls is efficient. I tested these predictions by comparing the diets and insect fauna in one open site with those in one closed site on the island of Hawai'i. As predicted, the dietary items were larger (t = 60.9, df = 259, p < 0.00001) in the open habitat (length = 18.9 ± 1.3 mm (mean ± SD); range 14-24 mm) than in the cluttered habitat (6.5 ± 1.6 mm; range 4-15 mm). In the cluttered habitat 86% of the insects fell into the three smallest length categories, while 52% of the insects in the open habitat fell into the two largest length categories. The preponderance of larger insects in the open habitat, with the consequent increase in detection range, enabled the bats to increase their flight speed despite their use of higher frequency echolocation calls. Rapid flight increases the rate at which insect prey are encountered and improves the foraging efficiency of bats. This provides evidence that bats are capable of altering their foraging strategy in response to prey characteristics and not just to the physical environment.

scholarly journals Description of Echolocation Call Parameters for Urban Bats in Vietnam as a Step Towards a More Integrated Acoustic Monitoring of Urban Wildlife in Southeast Asia

Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Long Kim Pham ◽  
Bang Van Tran ◽  
Quy Tan Le ◽  
Trung Thanh Nguyen ◽  
Christian C. Voigt
Keyword(s):  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Function Analysis ◽  
Quantitative Description ◽  
Southeast Asian ◽  
Asian Countries ◽  
Echolocation Call ◽  
Echolocation Calls ◽  
Pilot Work ◽  
Southeast Asian Countries

This study is the first step towards more systematic monitoring of urban bat fauna in Vietnam and other Southeast Asian countries by collecting bat echolocation call parameters in Ho Chi Minh and Tra Vinh cities. We captured urban bats and then recorded echolocation calls after releasing in a tent. Additional bat’s echolocation calls from the free-flying bats were recorded at the site where we captured bat. We used the obtained echolocation call parameters for a discriminant function analysis to test the accuracy of classifying these species based on their echolocation call parameters. Data from this pilot work revealed a low level of diversity for the studied bat assemblages. Additionally, the discriminant function analysis successfully classified bats to four bat species with an accuracy of >87.4%. On average, species assignments were correct for all calls from Taphozous melanopogon (100% success rate), for 70% of calls from Pipistrellus javanicus, for 80.8% of calls from Myotis hasseltii and 67.3% of calls from Scotophilus kuhlii. Our study comprises the first quantitative description of echolocation call parameters for urban bats of Vietnam. The success in classifying urban bats based on their echolocation call parameters provides a promising baseline for monitoring the effect of urbanization on bat assemblages in Vietnam and potentially also other Southeast Asian countries.

Gender Gaps in Electoral Turnout: Surveys versus Administrative Censuses

2021 ◽  
pp. 147892992110195
Author(s):  
Paulo Cox ◽  
Mauricio Morales Quiroga
Keyword(s):  
Survey Data ◽  
Gender Gap ◽  
Voter Turnout ◽  
Census Data ◽  
Electoral Participation ◽  
Gender Gaps ◽  
Electoral Turnout ◽  
The Individual ◽  
Official Data ◽  
Rule Out

Gender gaps in voter turnout are usually studied using opinion surveys rather than official census data. This is because administrative censuses usually do not disaggregate turnout according to voters’ sex. Without this official information, much of the research on gender gaps in electoral turnout relies on survey respondents’ self-reported behavior, either before or after an election. The decision to use survey data implies facing several potential drawbacks. Among them are the turnout overstatement bias and the attrition or nonresponse bias, both affecting the estimation of factors explaining turnout and any related statistical analysis. Furthermore, these biases may be correlated with covariates such as gender: men, more than women, may systematically overstate their electoral participation. We analyze turnout gender gaps in Chile, comparing national surveys with official administrative data, which in Chile are publicly available. Crucially, the latter includes the official record of sex, age, and the electoral behavior—whether the individual voted or not—for about 14 million registered individuals. Based on a series of statistical models, we find that analysis based on survey data is likely to rule out gender gaps in electoral participation. Carrying out the same exercises, but with official data, leads to the opposite conclusion, namely, that there is a sizable gender gap favoring women.

scholarly journals Don’t believe the mike: behavioural, directional, and environmental impacts on recorded bat echolocation call measures

2018 ◽  
Vol 96 (4) ◽  
pp. 283-288 ◽  
Author(s):  
J.M. Ratcliffe ◽  
L. Jakobsen
Keyword(s):  
Environmental Impacts ◽  
Acoustic Signals ◽  
Bird Song ◽  
Great Flexibility ◽  
Echolocation Call ◽  
Echolocation Calls ◽  
Acoustic Information ◽  
Species Overlap ◽  
Actual Signal ◽  
Nocturnal Mammals

Echolocation calls produced by bats in their larynges allow these flying, nocturnal mammals to orient and find food at night. The acoustic signals are not like bird song, and even individual bats exhibit great flexibility in call design and between-species overlap is common. As a result, identifying bats to species by their echolocation calls even in communities with few bat species can be difficult. Unfortunately, the situation is worse still. As a result of several factors — some to do with microphones, some with environment, some with bats, and the calls themselves — acoustic information transmitted to and transduced by microphones can be dramatically different from the actual signal produced by the bat and as would be recorded on axis, close to its mouth using ideal microphones under ideal conditions. We outline some of these pitfalls and discuss ways to make the best of a bad situation. Overall, however, we stress that many of these factors cannot be ignored and do impact our recordings.

Effects of a secondary task and working memory load on multisensory hand position

2012 ◽  
Vol 25 (0) ◽  
pp. 58
Author(s):  
Katrina Quinn ◽  
Francia Acosta-Saltos ◽  
Jan W. de Fockert ◽  
Charles Spence ◽  
Andrew J. Bremner
Keyword(s):  
Working Memory ◽  
Visual Information ◽  
Secondary Task ◽  
Memory Load ◽  
Memory Task ◽  
Hand Position ◽  
Working Memory Load ◽  
The Individual ◽  
Task Conditions ◽  
Relative Weighting

Information about where our hands are arises from different sensory modalities; chiefly proprioception and vision. These inputs differ in variability from situation to situation (or task to task). According to the idea of ‘optimal integration’, the information provided by different sources is combined in proportion to their relative reliabilities, thus maximizing the reliability of the combined estimate. It is uncertain whether optimal multisensory integration of multisensory contributions to limb position requires executive resources. If so, then it should be possible to observe effects of secondary task performance and/or working memory load (WML) on the relative weighting of the senses under conditions of crossmodal sensory conflict. Alternatively, an integrated signal may be affected by upstream influences of WML or a secondary task on the reliabilities of the individual sensory inputs. We examine these possibilities in two experiments which examine effects of WML on reaching tasks in which bisensory visual-proprioceptive (Exp. 1), and unisensory proprioceptive (Exp. 2) cues to hand position are provided. WML increased visual capture under conditions of visual-proprioceptive conflict, regardless of the direction of visual-proprioceptive conflict, and the degree of load imposed. This indicates that task-switching (rather than WML load) leads to an increased reliance on visual information regardless of its task-specific reliability (Exp. 1). This could not be explained due to an increase in the variability of proprioception under secondary working memory task conditions (Exp. 2). We conclude that executive resources are involved in the relative weighting of visual and proprioceptive cues to hand position.

scholarly journals Roots of tolerance among second-generation immigrants

2019 ◽  
Vol 15 (6) ◽  
pp. 999-1016 ◽  
Author(s):  
Niclas Berggren ◽  
Martin Ljunge ◽  
Therese Nilsson
Keyword(s):  
Second Generation ◽  
Individual Choice ◽  
Reverse Causality ◽  
Instrumental Variable Analysis ◽  
Second Generation Immigrants ◽  
European Culture ◽  
Formal And Informal Institutions ◽  
Rigorous Study ◽  
The Individual ◽  
Rule Out

AbstractTolerance – respecting individual choice and differences among people – is a prominent feature of modern European culture. That immigrants embrace this kind of liberal value is arguably important for integration, a central policy goal. We provide a rigorous study of what factors in the ancestral countries of second-generation immigrants – including formal and informal institutions – predict their level of tolerance towards gay people. Using the epidemiological method allows us to rule out reverse causality. Out of the 46 factors examined, one emerges as very robust: a Muslim ancestral background. Tolerance towards gay people is lower the larger the share of Muslims in the country from which the parents emigrated. An instrumental-variable analysis shows that the main mechanism is not through the individual being a Muslim, but through the individual being highly religious. Two additional attitudes among people in the ancestral country (valuing children being tolerant and respectful, and valuing children taking responsibility), as well as impartial institutions in the ancestral country, predict higher individual tolerance. Our findings thus point to an important role for both formal- and informal-institutional background factors in shaping tolerance.

Bats are still not birds in the digital era: echolocation call variation and why it matters for bat species identification

2018 ◽  
Vol 96 (2) ◽  
pp. 63-78 ◽  
Author(s):  
Danilo Russo ◽  
Leonardo Ancillotto ◽  
Gareth Jones
Keyword(s):  
Adaptive Significance ◽  
Bird Songs ◽  
Echolocation Call ◽  
Comprehensive Overview ◽  
Echolocation Calls ◽  
Digital Era ◽  
Call Classification ◽  
Acoustic Surveys ◽  
And Behavior ◽  
And Control

The recording and analysis of echolocation calls are fundamental methods used to study bat distribution, ecology, and behavior. However, the goal of identifying bats in flight from their echolocation calls is not always possible. Unlike bird songs, bat calls show large variation that often makes identification challenging. The problem has not been fully overcome by modern digital-based hardware and software for bat call recording and analysis. Besides providing fundamental insights into bat physiology, ecology, and behavior, a better understanding of call variation is therefore crucial to best recognize limits and perspectives of call classification. We provide a comprehensive overview of sources of interspecific and intraspecific echolocation call variations, illustrating its adaptive significance and highlighting gaps in knowledge. We remark that further research is needed to better comprehend call variation and control for it more effectively in sound analysis. Despite the state-of-art technology in this field, combining acoustic surveys with capture and roost search, as well as limiting identification to species with distinctive calls, still represent the safest way of conducting bat surveys.

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.

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