The calling songs of male spring field crickets (Gryllus veletis) change as males age

Behaviour ◽  
2011 ◽  
Vol 148 (9-10) ◽  
pp. 1045-1065 ◽  
Author(s):  
Susan M. Bertram ◽  
Lauren P. Fitzsimmons
Keyword(s):  
Longitudinal Study ◽  
Female Preference ◽  
Field Cricket ◽  
Mate Attraction ◽  
Call Structure ◽  
Field Crickets ◽  
Sexual Traits ◽  
Gryllus Veletis ◽  
The Relationship ◽  
Older Males

AbstractSexual traits are typically thought to convey information about a male's quality or condition. Female preference for older males has been documented in many taxa, but the evidence that males signal their age is inconclusive. We investigated lifetime patterns of acoustic mate attraction signalling in a longitudinal study of the spring field cricket, Gryllus veletis. We recorded males continuously throughout their lives, such that every pulse of sound produced by every male was analyzed. Our study answers two main questions: (1) Do calls change as males age? Our results reveal that the calls of male spring field crickets change with age; the calls of older males were quieter, with more silent periods within and between chirps, and produced less often than those of younger males. As males aged most of the changes in call structure reflect decreased calling effort. (2) What is the relationship between calling effort and longevity? Lifetime calling effort was positively related to longevity, such that males that called the most over their life also lived longer than males that called less. Together, our findings provide the most thorough exploration of lifetime signalling patterns in crickets to date.

scholarly journals Balancing Selection on Electrophoretic Variation of Phosphoglucose Isomerase in Two Species of Field Cricket: Gryllus veletis and G. pennsylvanicus

Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 609-621
Author(s):  
Laura A Katz ◽  
Richard G Harrison
Keyword(s):  
Balancing Selection ◽  
Emergent Property ◽  
Phosphoglucose Isomerase ◽  
Field Cricket ◽  
Nucleotide Variation ◽  
Eastern United States ◽  
Electrophoretic Variation ◽  
Sympatric Populations ◽  
Field Crickets ◽  
Gryllus Veletis

Two species of crickets, Gryllus veletis and G. pennsylvanicus, share six electrophoretic mobility classes for the enzyme phosphoglucose isomerase (PGI), despite evidence from other genetic markers that the two species are not closely related within eastern North American field crickets. Moreover, the frequencies of the two most common PGI electrophoretic classes (PGI-100 and PGI-65) covary in sympatric populations of these species in the eastern United States, suggesting that PGI may be subject to trans-specific balancing selection. To determine the molecular basis of the electrophoretic variation, we characterized the DNA sequence of the Pgi gene from 29 crickets (15 G. veletis and 14 G. pennsylvanicus). Amino acid substitutions that distinguish the electrophoretic classes are not the same in the two species, and there is no evidence that specific replacement substitutions represent trans-specific polymorphism. In particular, the amino acids that diagnose the PGI-65 allele relative to the PGI-100 allele differ both between G. veletis and G. pennsylvanicus and within G. pennsylvanicus. The heterogeneity among electrophoretic classes that covary in sympatric populations coupled with analysis of patterns of nucleotide variation suggest that Pgi is not evolving neutrally. Instead, the data are consistent with balancing selection operating on an emergent property of the PGI protein.

scholarly journals Obligately silent males sire more offspring than singers in a rapidly evolving cricket population

2019 ◽  
Vol 15 (7) ◽  
pp. 20190198 ◽  
Author(s):  
Justa L. Heinen-Kay ◽  
Ellen M. Urquhart ◽  
Marlene Zuk
Keyword(s):  
Evolutionary Biology ◽  
Rapid Evolution ◽  
Calling Song ◽  
Wild Populations ◽  
Field Crickets ◽  
Offspring Production ◽  
In The Wild ◽  
Sexual Traits ◽  
Acoustic Experience ◽  
Older Males

How sexual traits are gained and lost in the wild remains an important question in evolutionary biology. Pacific field crickets ( Teleogryllus oceanicus ) in Hawaii provide an unprecedented opportunity to investigate the factors facilitating evolutionary loss of a sexual signal in real time. Natural selection from an acoustically orienting parasitoid fly drove rapid evolution of a novel, silent male morph. While silent (flatwing) males enjoy protection from the fly, they face difficulty attracting mates. We tested how offspring production varies in association with three male attributes affected by the spread of flatwing: wing morph (flatwing or normal-wing), age (flatwings should survive longer than singers) and exposure to calling song during rearing (wild populations with many flatwings lack ambient calling song). Per mating event, flatwings sired more offspring than singers and older males were mounted more quickly by females when presented with standard courtship song. Despite prior work showing that male age and acoustic experience influence sperm characteristics associated with fertilization, age and song exposure had no influence on male offspring production per mating. This represents the first evidence that the silent male morph possesses a reproductive advantage that may help compensate for precopulatory barriers to mate attraction.

Assessing the Development of Operator Trust in Automation: A Longitudinal Study of an Autonomous Campus Shuttle

2020 ◽  
Vol 64 (1) ◽  
pp. 1421-1425
Author(s):  
Margaret Fowler ◽  
Farzan Sasangohar ◽  
Bob Brydia
Keyword(s):  
Longitudinal Study ◽  
Significant Relationship ◽  
Autonomous Vehicle ◽  
Student Population ◽  
Tier 1 ◽  
Trust In Automation ◽  
Operational Issues ◽  
The Relationship ◽  
Over Time

A large public tier-1 university hosted an autonomous vehicle on campus for a 12-week demonstration. Throughout the deployment, the vehicle was operated autonomously and used 5 safety operators from the student population to take over shuttle operations, as necessary. Daily and weekly surveys as well as pre-and post-study interviews were used to investigate how operators’ trust developed and changed over time as well as the relationship between trust and operational issues that varied in severity. Results revealed that there was not a significant relationship between trust and severity of operational issues. Trust levels appeared to remain relatively consistent before, during and after the deployment.

scholarly journals Longitudinal study describing time to Salmonella seroconversion in piglets on three farrow-to-finish farms

2019 ◽  
Vol 6 (1) ◽  
pp. e000287 ◽  
Author(s):  
Maria Cevallos-Almeida ◽  
Christelle Fablet ◽  
Catherine Houdayer ◽  
Virginie Dorenlor ◽  
Florent Eono ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Elisa Test ◽  
Individual Factors ◽  
Serological Response ◽  
Factors Associated ◽  
Serological Status ◽  
Pig Farms ◽  
Human Salmonellosis ◽  
On Farm ◽  
The Relationship

BackgroundPigs are frequently colonised with Salmonella enterica, and this constitutes a major risk for human salmonellosis. The infection can be assessed by the serological response of pigs to S enterica. A longitudinal study was undertaken on-farm to correctly describe this serological response and investigate factors associated with age at Salmonella seroconversion.MethodsThree pig farms and in each farm three successive batches were considered. Per batch, 40 piglets were selected at random from 10 sows (four piglets per sow). Blood was sampled from sows one week after farrowing and from piglets at weeks 1, 6, 10, 14, 18 and 22 and at the slaughterhouse. Salmonella antibodies were detected in serum using a commercial ELISA test. Factors related to farm characteristics, batch management system, porcine reproductive and respiratory syndrome infection, and sows’ Salmonella serological status were recorded to assess their effect on age at seroconversion.ResultsAt week 1 after farrowing, 96.5 per cent of the sows had antibodies against Salmonella. The serological results of piglets at weeks 1 and 6 only were positively correlated with those of the sows. The average age at Salmonella seroconversion was 137±2.2 days (confidence interval at 95 per cent). The first seroconversions occurred from weeks 10 to 14, but most of the pigs (54.6 per cent) were seropositive at the end of the fattening period, with variations between farms and batches (28.9–75.7 per cent). Herd/farm was significantly associated with age at seroconversion.ConclusionThis longitudinal study allowed the authors to follow precisely the evolution of Salmonella seroconversion from maternity to slaughterhouse and confirm the relationship between the seroconversion of sows and serology of their piglets. Moreover, factors related to farm practices and management as a whole are more influential than individual factors (at the pig level) on age at Salmonella seroconversion.

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