Population differences in the schooling behaviour of the Trinidad guppy, Poecilia reticulata: adaptation or constraint?

1995 ◽  
Vol 73 (6) ◽  
pp. 1100-1105 ◽  
Author(s):  
Benoni H. Seghers ◽  
Anne E. Magurran
Keyword(s):  
Predation Risk ◽  
Genetic Divergence ◽  
Poecilia Reticulata ◽  
Low Risk ◽  
Population Differences ◽  
Phylogenetic Constraints ◽  
Schooling Behaviour ◽  
In The Wild ◽  
Two Populations ◽  
River Fish

Populations of the guppy Poecilia reticulata in Trinidad vary markedly in their tendency to school. In many cases this variation in behaviour can be attributed to variation in the predation regime: guppies that co-occur with the pike cichlid, Crenicichla alta, spend more time schooling and form larger schools than their counterparts from low-risk habitats. However, the association between schooling tendency and predation risk is not ubiquitous. In this paper we document the behaviour of guppies from populations in two Trinidad drainages. Guppies from the (Lower) Aripo River (in the Caroni drainage) display well-coordinated schooling behaviour irrespective of whether they are observed in the wild or raised under standard conditions in the laboratory. By comparison, Oropuche River guppies (from the Oropuche drainage) show only a weak schooling tendency. The contrast between the two populations is apparent even in newborn guppies. As pike cichlids are abundant at both sites it seems unlikely that reduced predation risk can account for the weaker schooling of the Oropuche River fish. The behavioural differences in the two drainages are paralleled by considerable genetic divergence and we therefore consider the possibility of phylogenetic constraints on the evolution of schooling.

Population Differences

2021 ◽  
pp. 155-170
Author(s):  
Áki J. Láruson ◽  
Floyd A. Reed
Keyword(s):  
Dna Fingerprinting ◽  
Genetic Divergence ◽  
Population Differences ◽  
Blue Whale ◽  
Two Populations

This chapter addresses different approaches to quantifying genetic divergence between populations. It discusses the concept of “missing heterozygosity” and uses this to quantify the level of divergence between two populations with a measure called FST. The chapter works through how to determine a population of origin from blue whale data and touches on the concept of DNA fingerprinting to identify individuals.

Risk Sensitive Courtship in the Guppy (Poecilia Reticulata)

Behaviour ◽  
1990 ◽  
Vol 112 (3-4) ◽  
pp. 194-201 ◽  
Author(s):  
Anne E. Magurran ◽  
Benoni H. Seghers
Keyword(s):  
Individual Differences ◽  
Poecilia Reticulata ◽  
Fish Predation ◽  
Lower Proportion ◽  
Courtship Behaviour ◽  
Population Differences ◽  
Reproductive Tactics ◽  
Risk Sensitive ◽  
Presence And Absence ◽  
Two Populations

AbstractThis study investigated population differences in the courtship behaviour of male guppies, Poecilia reticulata, in the presence and absence of predators. Two Trinidad populations were compared: the Lower Aripo where guppies occur sympatrically with a range of piscivores and the Upper Aripo where levels of fish predation are low. Upper Aripo males displayed risk-reckless courtship behaviour and did not reduce their sigmoid display rate or otherwise modify their courtship behaviour when threatened by two Astyanax bimaculatus. The courtship behaviour of the Lower Aripo males was, by contrast, risk sensitive. These fish performed a lower proportion of sigmoid displays and increased their level of sneaky mating attempts in the presence of predators. Although males from the two populations used both sneaky and conventional courtship behaviours there were individual differences in the use of the reproductive tactics.

scholarly journals Sender and receiver experience alters the response of fish to disturbance cues

2019 ◽  
Vol 66 (3) ◽  
pp. 255-261
Author(s):  
Jack A Goldman ◽  
Laurence E A Feyten ◽  
Indar W Ramnarine ◽  
Grant E Brown
Keyword(s):  
Predation Risk ◽  
Poecilia Reticulata ◽  
Laboratory Strain ◽  
Background Risk ◽  
Low Risk ◽  
Response Patterns ◽  
High Background ◽  
Pressure Shaping ◽  
High Predation ◽  
Disturbance Cues

Abstract Predation is a pervasive selection pressure, shaping morphological, physiological, and behavioral phenotypes of prey species. Recent studies have begun to examine how the effects of individual experience with predation risk shapes the use of publicly available risk assessment cues. Here, we investigated the effects of prior predation risk experience on disturbance cue production and use by Trinidadian guppies Poecilia reticulata under laboratory conditions. In our first experiment, we demonstrate that the response of guppies from a high predation population (Lopinot River) was dependent upon the source of disturbance cue senders (high vs. low predation populations). However, guppies collected from a low predation site (Upper Aripo River) exhibited similar responses to disturbance cues, regardless of the sender population. In our second experiment, we used laboratory strain guppies exposed to high versus low background risk conditions. Our results show an analogous response patterns as shown for our first experiment. Guppies exposed to high background risk conditions exhibited stronger responses to the disturbance cues collected from senders exposed to high (vs. low) risk conditions and guppies exposed to low risk conditions were not influenced by sender experience. Combined, our results suggest that experience with background predation risk significantly impacts both the production of and response to disturbance cues in guppies.

Sound transmission in the habitats of Japanese macaques and its possible effect on population differences in coo calls

Behaviour ◽  
2006 ◽  
Vol 143 (8) ◽  
pp. 993-1012 ◽  
Author(s):  
Toshiaki Tanaka ◽  
Hideki Sugiura ◽  
Nobuo Masataka
Keyword(s):  
Macaca Fuscata ◽  
Japanese Macaques ◽  
Population Difference ◽  
Population Differences ◽  
Macaca Fuscata Yakui ◽  
Acoustic Features ◽  
Pure Tones ◽  
Habitat Acoustics ◽  
Acoustic Environments ◽  
Two Populations

AbstractRecently, the acoustic features of coo calls were reported to differ between two populations of Japanese macaques (Macaca fuscata yakui), namely the Ohirayama and Yakushima populations. We hypothesized that this difference may arise through differences in the acoustic environments of the two habitats, and measured the degrees of transmission of pure tones (250-8000 Hz) and the coo calls of the two populations in each habitat. In the Ohirayama habitat, lower frequencies were transmitted more efficiently, and the low-pitched coo calls of the Ohirayama population showed significantly better transmission than the high-pitched calls of the Yakushima population. In the Yakushima habitat, the degrees of transmission of the calls of the two populations did not differ significantly. Therefore, the calls of the Ohirayama population possess acoustic features that allow better transmission in their own habitat, suggesting that the habitat acoustics may be a factor contributing to the population difference between the calls.

scholarly journals Bicycle Facilities Safest from Crime and Crashes: Perceptions of Residents Familiar with Higher Crime/Lower Income Neighborhoods in Boston

2019 ◽  
Vol 16 (3) ◽  
pp. 484 ◽  
Author(s):  
Anne Lusk ◽  
Walter Willett ◽  
Vivien Morris ◽  
Christopher Byner ◽  
Yanping Li
Keyword(s):  
Design Guidelines ◽  
Low Risk ◽  
Lower Income ◽  
Halfway House ◽  
Red Color ◽  
Significant Difference ◽  
Predominantly Minority ◽  
New Guidelines ◽  
Bicycle Design ◽  
Two Populations

While studies of bicyclist’s perceptions of crime and crash safety exist, it is also important to ask lower-income predominantly-minority residents what bicycle-route surface or context they perceive as safest from crime and crashes. With their insights, their chosen bike environments could be in engineering guidelines and built in their neighborhoods to improve residents’ health and lessen their risk of exposure to crime or crashing. This study involved two populations in Boston: (a) community-sense participants (eight groups-church/YMCA n = 116); and (b) street-sense participants (five groups-halfway house/homeless shelter/gang members n = 96). Participants ranked and described what they saw in 32 photographs of six types of bicycle environments. Quantitative data (Likert Scale 0–6 with 0 being low risk of crime/crash) involved regression analysis to test differences. Qualitative comments were categorized into 55 themes for surface or context and if high or low in association with crime or crashes. For crime, two-way cycle tracks had a significantly lower score (safest) than all others (2.35; p < 0.01) and share-use paths had a significantly higher score (least safe) (3.39; p < 0.01). For crashes, participants rated shared-use paths as safest (1.17) followed by two-way cycle tracks (1.68), one-way cycle tracks (2.95), bike lanes (4.06), sharrows (4.17), and roads (4.58), with a significant difference for any two groups (p < 0.01) except between bike lane and sharrow (p = 0.9). Street-sense participants ranked all, except shared-use paths, higher for crime and crash. For surface, wide two-way cycle tracks with freshly painted lines, stencils, and arrows were low risk for crime and a cycle track’s median, red color, stencils, and arrows low risk for crash. For context, clean signs, balconies, cafes, street lights, no cuts between buildings, and flowers were low risk for crime and witnesses, little traffic, and bike signals low risk for crash. As bicycle design guidelines and general Crime Perception Through Environmental Design (CPTED) principles do not include these details, perhaps new guidelines could be written.

scholarly journals Improving vulnerability remediation through better exploit prediction

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Jay Jacobs ◽  
Sasha Romanosky ◽  
Idris Adjerid ◽  
Wade Baker
Keyword(s):  
Machine Learning ◽  
High Risk ◽  
Small Body ◽  
Low Risk ◽  
Machine Learning Techniques ◽  
Outcome Variable ◽  
Remediation Strategies ◽  
Learning Techniques ◽  
In The Wild ◽  
Cyber Risk

Abstract Despite significant innovations in IT security products and research over the past 20 years, the information security field is still immature and struggling. Practitioners lack the ability to properly assess cyber risk, and decision-makers continue to be paralyzed by vulnerability scanners that overload their staff with mountains of scan results. In order to cope, firms prioritize vulnerability remediation using crude heuristics and limited data, though they are still too often breached by known vulnerabilities for which patches have existed for months or years. And so, the key challenge firms face is trying to identify a remediation strategy that best balances two competing forces. On one hand, it could attempt to patch all vulnerabilities on its network. While this would provide the greatest ‘coverage’ of vulnerabilities patched, it would inefficiently consume resources by fixing low-risk vulnerabilities. On the other hand, patching a few high-risk vulnerabilities would be highly ‘efficient’, but may leave the firm exposed to many other high-risk vulnerabilities. Using a large collection of multiple datasets together with machine learning techniques, we construct a series of vulnerability remediation strategies and compare how each perform in regard to trading off coverage and efficiency. We expand and improve upon the small body of literature that uses predictions of ‘published exploits’, by instead using ‘exploits in the wild’ as our outcome variable. We implement the machine learning models by classifying vulnerabilities according to high- and low-risk, where we consider high-risk vulnerabilities to be those that have been exploited in actual firm networks.

scholarly journals Large brains, short life: selection on brain size impacts intrinsic lifespan

2019 ◽  
Vol 15 (5) ◽  
pp. 20190137 ◽  
Author(s):  
Alexander Kotrschal ◽  
Alberto Corral-Lopez ◽  
Niclas Kolm
Keyword(s):  
Poecilia Reticulata ◽  
Brain Size ◽  
Positive Association ◽  
Energetic Cost ◽  
Accelerated Ageing ◽  
Extrinsic Mortality ◽  
Somatic Maintenance ◽  
Cognitive Benefits ◽  
In The Wild ◽  
Positive Correlations

The relationship between brain size and ageing is a paradox. The cognitive benefits of large brains should protect from extrinsic mortality and thus indirectly select for slower ageing. However, the substantial energetic cost of neural tissue may also impact the energetic budget of large-brained organisms, causing less investment in somatic maintenance and thereby faster ageing. While the positive association between brain size and survival in the wild is well established, no studies exist on the direct effects of brain size on ageing. Here we test how brain size influences intrinsic ageing in guppy ( Poecilia reticulata ) brain size selection lines with 12% difference in relative brain size. Measuring survival under benign conditions, we find that large-brained animals live 22% shorter than small-brained animals and the effect is similar in both males and females. Our results suggest a trade-off between investment into brain size and somatic maintenance. This implies that the link between brain size and ageing is contingent on the mechanism of mortality, and selection for positive correlations between brain size and ageing should occur mainly under cognition-driven survival benefits from increased brain size. We show that accelerated ageing can be a cost of evolving a larger brain.

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