The echolocation calls of the spotted bat Euderma maculatum are relatively inaudible to moths

1997 ◽  
Vol 200 (1) ◽  
pp. 129-137 ◽  
Author(s):  
J Fullard ◽  
J Dawson
Keyword(s):  
Eptesicus Fuscus ◽  
Auditory Threshold ◽  
Western Canada ◽  
Acoustic Characteristics ◽  
Insectivorous Bats ◽  
Echolocation Calls ◽  
In The Wild ◽  
A Site ◽  
Approach Phase

Previous studies of the spotted bat Euderma maculatum have demonstrated that this bat emits echolocation calls that are lower in frequency, shorter in duration and fainter in intensity compared with those of most other insectivorous bats, acoustic characteristics which should render it less conspicuous to eared moths. We tested this prediction by monitoring electrophysiologically the ears of sympatric noctuoid (noctuid, arctiid and notodontid) moths in a site in western Canada. Auditory threshold curves demonstrate that most of the moths tested are less responsive to the calls of Eu. maculatum than to those of another sympatric bat, Eptesicus fuscus. Playbacks to moth ears of pre-recorded search- and approach-phase echolocation calls of Eu. maculatum and Ep. fuscus further demonstrate that the calls of Eu. maculatum are poorly detectable to moths and, in some cases, completely inaudible. We estimate that, in the wild, an average noctuoid moth would detect the calls of Eu. maculatum at distances of less than 1 m as opposed to the calls of Ep. fuscus which should be first heard at distances of 20­25 m. Although most moths are unable to adequately hear Eu. maculatum, the observation that two individuals possessed ears sensitive to this bat's calls suggests the existence of auditory pre-adaptation to this type of echolocation.

ALTERNATION OF ECHOLOCATION CALLS IN 5 SPECIES OF AERIAL-FEEDING INSECTIVOROUS BATS FROM MALAYSIA

2003 ◽  
Vol 84 (1) ◽  
pp. 205-215 ◽  
Author(s):  
Tigga Kingston ◽  
Gareth Jones ◽  
Zubaid Akbar ◽  
Thomas H. Kunz
Keyword(s):  
Insectivorous Bats ◽  
Echolocation Calls

Echolocation and feeding behaviour of Taphozous mauritianus (Chiroptera: Emballonuridae)

1980 ◽  
Vol 58 (10) ◽  
pp. 1774-1777 ◽  
Author(s):  
M. B. Fenton ◽  
G. P. Bell ◽  
D. W. Thomas
Keyword(s):  
Long Range ◽  
Feeding Behaviour ◽  
Second Harmonic ◽  
Feeding Strategy ◽  
Rapid Rise ◽  
Constant Frequency ◽  
Insectivorous Bats ◽  
Sound Energy ◽  
Echolocation Calls ◽  
Human Ear

Observations of free-flying bats in the field in Zimbabwe indicated that Taphozous mauritianus uses multiharmonic constant frequency (CF) search calls followed by multiharmonic approach and terminal calls that combine shallow and steep frequency modulated (FM) sweeps during approaches to targets. The three phases of calls all have rapid rise times to full amplitude, and most of the sound energy is in the second harmonic; the fundamental is usually present (11–13 kHz), making the calls clearly audible to the unaided human ear. This combination of characters, but particularly the CF search calls, serves to distinguish these echolocation calls from those of other insectivorous bats. One light-tagged individual hunting insects reacted to targets at distances of about 3 m, suggesting a long-range feeding strategy.

scholarly journals Amino Acid Starvation Enhances Programmed Ribosomal Frameshift in Metavirus Ty3 of Saccharomyces cerevisiae

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Sezai Türkel
Keyword(s):  
Amino Acid ◽  
Amino Acid Starvation ◽  
Yeast Cells ◽  
Dependent Manner ◽  
Coding Region ◽  
Coding Regions ◽  
In The Wild ◽  
Amino Acid Depletion ◽  
A Site ◽  
Wild Type Yeast

Ty3 is a retroviral-like element and propagates with a retroviral-like mechanism within the yeast cells. Ty3 mRNA contains two coding regions, which are GAG3 and POL3. The coding region POL3 is translated as a GAG3-POL3 fusion protein by a +1 programmed frameshift. In this study, it was shown that the Ty3 frameshift frequency is significantly increased by amino acid starvation in a Gcn2p complex dependent manner. When the yeast cells were subjected to amino acid starvation, the frameshift frequency of Ty3 increased more than 2-fold in the wild-type yeast cells, mostly independent of Gcn4p. However, Ty3 frameshift frequency remained at basal level in the gcn1, gcn20, or gcn2 mutant yeast cells in amino acid starved yeasts. Gcn1p forms a complex with Gcn2p and Gcn20p and is involved in the sensing of uncharged tRNAs on the ribosomal A-site during translation. Increases in uncharged tRNA levels due to amino acid depletion lead to ribosomal pauses. These ribosomal pauses are significant actors in the regulation of Ty3 frameshift frequency. Results of this research revealed that frameshift frequency in Ty3 is regulated by the Gcn2p complex in response to amino acid starvation in yeast.

Jamming bat echolocation: the clicks of arctiid moths

1979 ◽  
Vol 57 (3) ◽  
pp. 647-649 ◽  
Author(s):  
James H. Fullard ◽  
M. Brock Fenton ◽  
James A. Simmons
Keyword(s):  
Information Processing ◽  
Power Spectra ◽  
Acoustic Characteristics ◽  
Echolocation Calls ◽  
Auditory Systems ◽  
Time Structures ◽  
And Function

Analysis of the clicks produced by some arctiid moths shows that their acoustic characteristics (power spectra and frequency–time structures) are remarkably similar to those of frequency-modulated echolocation calls produced by many bats as they close with their prey. We suspect that the clicks are initially processed as echoes by the auditory systems of these bats and function by interfering with information processing by the bat.

scholarly journals Population parameters of the endangered titi monkey, Callicebus coimbrai Kobayashi and Langguth, 1999, in the fragmented landscape of southern Sergipe, Brazil

2011 ◽  
Vol 71 (3) ◽  
pp. 569-575 ◽  
Author(s):  
RRD. Chagas ◽  
SF. Ferrari
Keyword(s):  
Atlantic Forest ◽  
Considerable Proportion ◽  
Reliable Estimate ◽  
Line Transect ◽  
Fragmented Landscape ◽  
Forest Fragments ◽  
Population Parameters ◽  
Data Set ◽  
In The Wild ◽  
A Site

The recently-discovered titi, Callicebus coimbrai, is endemic to the coastal Brazilian Atlantic Forest south of the São Francisco River, a region with a long tradition of deforestation. While a number of C. coimbrai populations have now been identified, little is known about basic population parameters. Considering the importance of this information for conservation planning, the population of a site in southern Sergipe (with a total area of forest of approximately 500 ha) was surveyed between April and October 2008. Standard line transect procedures were used in the four largest fragments, and additional monitoring included the use of playback broadcasts for the observation of titi groups. The presence of titis was confirmed in all the forest fragments at the site, including one of only five hectares. Two other primates - Callithrix jacchus and Cebus xanthosternos - were also recorded at the site, but were less abundant than titis. A total transect walk of 476 km provided 164 sightings of primates, the majority of which (104) were of Callicebus coimbrai. Titi groups ranged in size between two and five individuals. The most reliable estimate of overall population density, derived from the combined data set, was 12.6 individuals per km²;, although density was much higher in smaller (more disturbed) fragments. The total population of Callicebus coimbrai at the site was estimated to be at least 50 individuals, which may represent a considerable proportion of the population of the species remaining in the wild. In addition to its apparent tolerance of habitat fragmentation, densities of C. coimbrai recorded at the site compare favourably with those of other Atlantic Forest titi species.

scholarly journals A Palindromic RNA Sequence as Common Breakpoint Contributor to Copy-choice Recombination in SARS-CoV-2

2020 ◽  
Author(s):  
William R. Gallaher
Keyword(s):  
Rna Structure ◽  
Bioinformatic Analysis ◽  
The Novel ◽  
Rna Sequence ◽  
Short Oligonucleotide ◽  
Adaptive Mutations ◽  
Endoproteolytic Cleavage ◽  
In The Wild ◽  
Novel Coronavirus ◽  
A Site

Abstract Much remains unknown concerning the origin of the novel pandemic Coronavirus that has raged across the globe since emerging in Wuhan of Hubei province, near the center of the People’s Republic of China in December of 2019. All current strains of Coronaviridae have arisen by a combination of incremental adaptive mutations, against the backdrop of many recombinational events throughout the past, rendering each a unique mosaic of RNA sequence from diverse sources. The consensus among virologists is that the base sequence of the novel coronavirus, designated SARS-CoV-2, was derived from a common ancestor of a bat coronavirus, represented by the strain RaTG13 isolated in Yunnan province in 2013. Into that ancestral genetic background, several recombination events have since occurred from other divergent bat-derived coronaviruses, resulting in localized discordance between the two. One such event left SARS-CoV-2 with a receptor binding domain (RBD) capable of binding the human ACE-2 receptor lacking in RaTG13, and a second event uniquely added to SARS-CoV-2 a site specific for furin, capable of efficient endoproteolytic cleavage and activation of the spike glycoprotein responsible for virus entry and cell fusion. This paper demonstrates by bioinformatic analysis that such recombinational events are facilitated by short oligonucleotide “breakpoint sequences”, similar to CAGAC, that direct recombination naturally to certain positions in the genome at the boundaries between blocks of RNA code and potentially RNA structure. This “breakpoint sequence hypothesis” provides a natural explanation for the biogenesis of SARS-CoV-2 over time and in the wild.

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