scholarly journals Predation risk alters life history strategies in an oceanic copepod

Ecology ◽  
2020 ◽  
Author(s):  
Kristina Øie Kvile ◽  
Dag Altin ◽  
Lotte Thommesen ◽  
Josefin Titelman
Keyword(s):  
Life History ◽  
Predation Risk ◽  
Life History Strategies

scholarly journals Breeding Biology of Passerines in a Subtropical Montane Forest in Northwestern Argentina

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 321-333 ◽  
Author(s):  
Sonya K. Auer ◽  
Ronald D. Bassar ◽  
Joseph J. Fontaine ◽  
Thomas E. Martin
Keyword(s):  
Life History ◽  
Predation Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Life History Strategies ◽  
Temperate Species ◽  
Egg Mass ◽  
Breeding Ecology ◽  
Feeding Rates ◽  
Northwestern Argentina

Abstract The breeding ecology of south temperate bird species is less widely known than that of north temperate species, yet because they comprise a large portion of the world's avian diversity, knowledge of their breeding ecology can contribute to a more comprehensive understanding of the geographic diversity of avian reproductive traits and life history strategies. We provide the first detailed examination of the reproductive strategies of 18 forest passerines of subtropical, northwestern Argentina. Mean clutch sizes were smaller and egg mass was greater than for north temperate birds, but differed among species and nest types, with cavity-nesters having larger clutches than species with open-cup and enclosed nests. Across all species, the average breeding season duration was 50 days; thus, the common perception that southern species have smaller clutch sizes because of longer breeding seasons is not supported in this community. Daily nest predation rates were influenced by nest type, cavity nests suffering the least from predation, as found in north temperate systems. Only females incubated eggs in all but one species, whereas both parents fed and cared for nestlings in all species. Mean nest attentiveness was low compared to north temperate passerines. Mean hourly nestling feeding rates differed among species and were negatively related to nest predation risk. In short, coexisting species in this subtropical forest varied in their life history strategies, in part correlated with variation in nest predation risk, but also differing from north temperate species.

scholarly journals Sex-specific predation risk and the evolution of sexual dimorphism in immunocompetence: a theoretical analysis

2014 ◽  
Author(s):  
Benjamin Fanson ◽  
Eirik Søvik
Keyword(s):  
Sexual Selection ◽  
Life History ◽  
Sexual Dimorphism ◽  
Immune Function ◽  
Predation Risk ◽  
Reproductive Effort ◽  
Life History Strategies ◽  
Defense Strategies ◽  
Differential Predation ◽  
Predation Costs

Sexual dimorphism in immunocompetence, with males having lower immune function, is a prevalent pattern in nature. The main evolutionary explanation for this pattern is that males preferentially allocate resources away from immune function and towards reproductive effort to increase their competitiveness for limited females. However, the role of differential predation risk between the sexes has not been considered, despite predation risk being a major driver of life history strategies and male sexual traits often having associated predation costs. It is unclear whether increased predation risk should increase or decrease investment in immune function, as males have been shown to utilize both behavioural (e.g. decrease foraging activity) and/or life-history (e.g. decrease investment in sexual trait) defense strategies to manage predation risk. Here, we modelled optimal resource acquisition and allocation towards immune function under differential predation risk with multiple defense strategies. If males have limited defense strategies, increasing predation risk caused males to trade-off immune function for reproductive effort, leading to reduced immunocompetence. In contrast, if males can only decrease predation risk through reduction of reproductive effort (e.g. decrease colouration or calling rates), then increasing predation risk causes immune function to increase. If males can utilize multiple defense strategies and sexual selection is low, then males maintain a constant immune function as predation risk increases. Sexual selection robustly resulted in decreased immunocompetence. Overall, our results suggest that predation plays an important role in the evolution of sexual dimorphism in immunocompetence, but predicting its effect requires understanding the integrated defense strategies available.

scholarly journals Sex-specific predation risk and the evolution of sexual dimorphism in immunocompetence: a theoretical analysis

2014 ◽  
Author(s):  
Benjamin Fanson ◽  
Eirik Søvik
Keyword(s):  
Sexual Selection ◽  
Life History ◽  
Sexual Dimorphism ◽  
Immune Function ◽  
Predation Risk ◽  
Reproductive Effort ◽  
Life History Strategies ◽  
Defense Strategies ◽  
Differential Predation ◽  
Predation Costs

Sexual dimorphism in immunocompetence, with males having lower immune function, is a prevalent pattern in nature. The main evolutionary explanation for this pattern is that males preferentially allocate resources away from immune function and towards reproductive effort to increase their competitiveness for limited females. However, the role of differential predation risk between the sexes has not been considered, despite predation risk being a major driver of life history strategies and male sexual traits often having associated predation costs. It is unclear whether increased predation risk should increase or decrease investment in immune function, as males have been shown to utilize both behavioural (e.g. decrease foraging activity) and/or life-history (e.g. decrease investment in sexual trait) defense strategies to manage predation risk. Here, we modelled optimal resource acquisition and allocation towards immune function under differential predation risk with multiple defense strategies. If males have limited defense strategies, increasing predation risk caused males to trade-off immune function for reproductive effort, leading to reduced immunocompetence. In contrast, if males can only decrease predation risk through reduction of reproductive effort (e.g. decrease colouration or calling rates), then increasing predation risk causes immune function to increase. If males can utilize multiple defense strategies and sexual selection is low, then males maintain a constant immune function as predation risk increases. Sexual selection robustly resulted in decreased immunocompetence. Overall, our results suggest that predation plays an important role in the evolution of sexual dimorphism in immunocompetence, but predicting its effect requires understanding the integrated defense strategies available.

scholarly journals Natural variation in plant telomere length is associated with flowering time

2021 ◽  
Author(s):  
Jae Young Choi ◽  
Liliia R Abdulkina ◽  
Jun Yin ◽  
Inna B Chastukhina ◽  
John T Lovell ◽  
...  
Keyword(s):  
Life History ◽  
Telomere Length ◽  
Flowering Time ◽  
Dna Sequences ◽  
Genome Wide Association Study ◽  
Genomic Analysis ◽  
Life History Strategies ◽  
Length Variation ◽  
Chromosomal Structure ◽  
Chromosome Integrity

Abstract Telomeres are highly repetitive DNA sequences found at the ends of chromosomes that protect the chromosomes from deterioration during cell division. Here, using whole genome re-sequencing and terminal restriction fragment assays, we found substantial natural intraspecific variation in telomere length in Arabidopsis thaliana, rice (Oryza sativa), and maize (Zea mays). Genome-wide association study (GWAS) mapping in A. thaliana identified 13 regions with GWAS-significant associations underlying telomere length variation, including a region that harbors the telomerase reverse transcriptase (TERT) gene. Population genomic analysis provided evidence for a selective sweep at the TERT region associated with longer telomeres. We found that telomere length is negatively correlated with flowering time variation not only in A. thaliana, but also in maize and rice, indicating a link between life history traits and chromosome integrity. Our results point to several possible reasons for this correlation, including the possibility that longer telomeres may be more adaptive in plants that have faster developmental rates (and therefore flower earlier). Our work suggests that chromosomal structure itself might be an adaptive trait associated with plant life history strategies.

Intraspecific hybridization, life history strategies and potential invasion success in a parasitoid wasp

2012 ◽  
Vol 26 (6) ◽  
pp. 1311-1329 ◽  
Author(s):  
Chiara Benvenuto ◽  
Sandrine Cheyppe-Buchmann ◽  
Gérald Bermond ◽  
Nicolas Ris ◽  
Xavier Fauvergue
Keyword(s):  
Life History ◽  
Parasitoid Wasp ◽  
Invasion Success ◽  
Life History Strategies ◽  
Intraspecific Hybridization

scholarly journals High Genetic Variance in Life-History Strategies within Invasive Populations by Way of Multiple Introductions

2008 ◽  
Vol 18 (5) ◽  
pp. 363-367 ◽  
Author(s):  
Benoît Facon ◽  
Jean-Pierre Pointier ◽  
Philippe Jarne ◽  
Violette Sarda ◽  
Patrice David
Keyword(s):  
Life History ◽  
Genetic Variance ◽  
Life History Strategies ◽  
Multiple Introductions
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