scholarly journals Personality predicts individual responsiveness to the risks of starvation and predation

2011 ◽  
Vol 279 (1735) ◽  
pp. 1919-1926 ◽  
Author(s):  
J. L. Quinn ◽  
E. F. Cole ◽  
J. Bates ◽  
R. W. Payne ◽  
W. Cresswell
Keyword(s):  
Life Histories ◽  
Parus Major ◽  
Poor Quality ◽  
Trade Off ◽  
Quality Food ◽  
Individual Personality ◽  
Temporal And Spatial ◽  
Time Spent Feeding ◽  
Individual Responsiveness ◽  
Starvation Risk

Theory suggests that individual personality is tightly linked to individual life histories and to environmental variation. The reactive–proactive axis, for example, is thought to reflect whether individuals prioritize productivity or survival, mutually exclusive options that can be caused by conflicts between foraging and anti-predation behaviour. Evidence for this trade-off hypothesis, however, is limited. Here, we tested experimentally whether exploration behaviour (EB), an assay of proactivity, could explain how great tits ( Parus major ) respond to changes in starvation and predation risk. Individuals were presented with two feeders, holding good or poor quality food, which interchanged between safe and dangerous positions 10 m apart, across two 24 h treatments. Starvation risk was assumed to be highest in the morning and lowest in the afternoon. The proportion of time spent feeding on good quality food (PTG) rather than poor quality food was repeatable within treatments, but individuals varied in how PTG changed with respect to predation- and starvation-risk across treatments. This individual plasticity variation in foraging behaviour was linked to EB, as predicted by the reactive–proactive axis, but only among individuals in dominant social classes. Our results support the trade-off hypothesis at the level of individuals in a wild population, and suggest that fine-scale temporal and spatial variation may play important roles in the evolution of personality.

Pores versus spores: competition between photosynthesis and reproduction is constrained by leaf mass per unit area (LMA) in ferns

2020 ◽  
Author(s):  
K G Srikanta Dani ◽  
Jose Mathew ◽  
T M Nila-Mohan ◽  
Raju Antony ◽  
S Suresh ◽  
...  
Keyword(s):  
Life Histories ◽  
Resource Constraints ◽  
Time Window ◽  
Unit Area ◽  
Stomatal Density ◽  
High Fertility ◽  
Leaf Lifespan ◽  
Trade Off ◽  
Terrestrial Species ◽  
Leaf Mass

Abstract Diversity in plant life histories is primarily that found in the rate and duration of photosynthetic (vegetative) and reproductive growth. However, direct evidence for an anticipated trade-off between photosynthesis and reproduction is lacking in any plant lineage. Ferns allocate leaf space and resources to both photosynthesis and reproduction, potentially leading to competition for leaf resources between stomatal pores and reproductive spores. We hypothesized that a trade-off between stomatal density (StD; a proxy for photosynthetic capacity) and sporangial density (SpD; a measure of fertility) has evolved in monomorphic ferns due to the common space, time and resource constraints imposed by a highly conserved and globally low leaf mass per unit area (LMA) in ferns, where any increase in LMA indicated greater construction cost and longer leaf lifespan. We measured LMA, StD and SpD in 40 fern species in India that represented both monomorphic and dimorphic conditions from both terrestrial and epiphytic habits. Both StD and SpD showed a 50-fold range in monomorphic species whereas LMA was more conserved (six-fold range). LMA of terrestrial ferns was significantly lower than that of epiphytic ferns. Linear regression between LMA and StD was significantly positive in dimorphic terrestrial ferns (showing the lowest LMA among all ferns) and significantly negative in monomorphic epiphytic ferns (showing the highest LMA among all ferns). Dimorphic terrestrial ferns were highly fecund on their fertile leaves and showed a significantly higher StD to LMA ratio on their sterile leaves compared to monomorphic terrestrial ferns. Dimorphic ferns seem to maximize both StD and SpD by physical separation of photosynthesis and reproduction, and their characteristically low LMA (shorter leaf lifespan = smaller time window) potentially selects for high StD and high fertility. The regression between StD and SpD in monomorphic ferns was significantly linear and positive, although comparisons among closely related species (within families) showed negative correlations when both StD and SpD were high, captured also by a significant quadratic regression between StD and SpD in monomorphic ferns. Monomorphic terrestrial species bearing more spores per stomata showed relatively low LMA whereas those producing fewer spores per stomata possessed leaves with relatively high LMA. Monomorphic epiphytes produced as many spores as terrestrial species but showed significantly low StD for their high LMA. We discuss the evolutionary reasons behind these trends and conclude that monomorphic terrestrial ferns with high LMA (long leaf lifespan) tend to prioritize photosynthesis over reproduction, while monomorphic epiphytes (always high LMA) are significantly more fertile for lower photosynthesis. The role of LMA in framing the rules of competition between stomata and sporangia in monomorphic ferns provides a template for how photosynthesis may directly or indirectly influence reproductive strategies (and vice versa) in all land plants.

scholarly journals Transcriptomic signatures of ageing vary in solitary and social forms of an orchid bee

2020 ◽  
Author(s):  
Alice C. Séguret ◽  
Eckart Stolle ◽  
Fernando A. Fleites-Ayil ◽  
José Javier G. Quezada-Euán ◽  
Klaus Hartfelder ◽  
...  
Keyword(s):  
Gene Expression ◽  
Juvenile Hormone ◽  
Candidate Genes ◽  
Gene Networks ◽  
Life Histories ◽  
Molecular Mechanisms ◽  
Trade Off ◽  
Eusocial Insects ◽  
Orchid Bee ◽  
Social Forms

AbstractEusocial insect queens are remarkable in their ability to maximise both fecundity and longevity, thus escaping the typical trade-off between these two traits. In species exhibiting complex eusocial behaviour, several mechanisms have been proposed to underlie the remoulding of the trade-off, such as reshaping of the juvenile hormone pathway, or caste-specific susceptibility to oxidative stress. However, it remains a challenge to disentangle the molecular mechanisms underlying the remoulding of the trade-off in eusocial insects from caste-specific physiological attributes that have subsequently arisen due to their different life histories. Socially plastic species such as the orchid bee Euglossa viridissima represent excellent models to address the role of sociality per se in longevity as they allow direct comparisons of solitary and social individuals within a common genetic background. We present data on gene expression and juvenile hormone levels from young and old bees, from both solitary and social nests. We found 940 genes to be differentially expressed with age in solitary females, versus only 14 genes in social dominant females, and seven genes in subordinate females. We performed a weighted gene co-expression network analysis to further highlight candidate genes related to ageing in this species. Primary “ageing gene” candidates were related to protein synthesis, gene expression, immunity and venom production. Remarkably, juvenile hormone titres did not vary with age or social status. These results represent an important step in understanding the proximate mechanisms underlying the remodeling of the fecundity/longevity trade-off that accompanies the evolutionary transition from solitary life to eusociality.Significance statementThe remarkably long lifespan of the queens of eusocial insects despite their high reproductive output suggests that they are not subject to the widespread trade-off between fecundity and longevity that governs solitary animal life histories, yet surprisingly little is known of the molecular mechanisms underpinning their longevity. Using a socially plastic bee in which some individuals of a population are social whilst others are solitary, we identified hundreds of candidate genes and related gene networks that are involved in the remoulding of the fecundity/longevity tradeoff. As well as identifying candidate ageing genes, our data suggest that even in incipient stages of sociality there is a marked reprogramming of ageing; long live the queen.

scholarly journals Personality is associated with dominance in a social feeding context in the great tit

Behaviour ◽  
2019 ◽  
Vol 156 (13-14) ◽  
pp. 1419-1434
Author(s):  
Nehafta Bibi ◽  
Yusheng Wei ◽  
Hongwei Xu ◽  
Jingnan Liang ◽  
Ijaz Hussain ◽  
...  
Keyword(s):  
Social Context ◽  
Personality Traits ◽  
Parus Major ◽  
Novel Object ◽  
Novel Environment ◽  
Personality Differences ◽  
Individual Personality ◽  
Behavioural Types ◽  
Fitness Consequence ◽  
Feeding Context

Abstract Despite the growing interest in consistent individual differences in behaviour (animal personality), the influence of social context on different behavioural types remains poorly understood. The suite of correlated behaviours within and across contexts is called behavioural syndromes. Most personality studies have investigated consistent individual behavioural types and their consequences in a asocial context, however few studies have considered the influence of social context on individual behaviour. In addition, the evolutionary and ecological consequences of personality differences in social context remain unknown. In the present study, we confirm individual personality in Great tits (Parus major) using room exploration and neophobia tests. As a result of these two tests, repeatability and correlational structure of two personality traits were investigated. Additionally we assessed the extent to which personality influences dominance in a social feeding context. Great tits remained consistent in their personality traits (exploration and neophobia). Individuals who explored a novel environment faster also approached a novel object faster, while those who spent more time exploring a novel environment were also slower to approach a novel object. In a social feeding context personality was linked to dominance: with proactive individuals being more likely to be dominant. Our result provides evidence of the importance of social context in a wild population of birds and may have fitness consequence, both for focal individuals and their conspecifics.

Trade-off-invariant rules for evolutionary stable life histories

Nature ◽  
1997 ◽  
Vol 387 (6631) ◽  
pp. 393-394 ◽  
Author(s):  
Eric L. Charnov
Keyword(s):  
Life Histories ◽  
Trade Off

scholarly journals Secondary and Micronutrient Management Practices in Organic Farming- An Overview

2019 ◽  
Vol 7 (1) ◽  
pp. 04-18 ◽  
Author(s):  
M. R. Anand ◽  
H.D Shiva Kumar ◽  
Poojitha Kommireddy ◽  
K.N.Kalyana Murthy
Keyword(s):  
Organic Farming ◽  
Management Practices ◽  
Soil Health ◽  
Cropping System ◽  
Poor Quality ◽  
Soil Productivity ◽  
Nutrient Deficiencies ◽  
Human Beings ◽  
Chemical Fertilizers ◽  
Quality Food

Modern agriculture, no doubt has paved the way for “Green Revolution”, but it has led to the application of heavy doses of chemical fertilizers and pesticides with the sole objective of maximizing the yield. The unbalanced and continuous use of chemical fertilizers in intensive cropping system is causing deterioration of soil health, multi-nutrient deficiencies, low productivity, poor quality and environmental hazards. Poor quality of food and fodder has caused serious health problems and disorders in both animals and human beings. Now, the agriculture research is focused on evolving ecologically sound, biologically sustainable and socio economically viable technologies like organic farming which includes local organic sources of nutrients without using chemical fertilizers and pesticides. Adoption of organic farming minimizes the environmental pollution and maintain long-term soil fertility by improving soil organic matter and essential plant nutrients including secondary and micronutrients. For producing quality food by sustaining the soil productivity and soil health are the challenges before us on one side and minimizing the pressure on non renewable sources or limited available sources on other hand needs immediate attention by all the stakeholders engaged in agriculture. Application of technologies available in organic farming and use of all locally available organic sources particularly on farm biomass which are rich in secondary and micronutrients will meet the twin objective of quality food production and reducing the pressure on non renewable resources.

scholarly journals Interactive Communication Between Male and Female Great Tits (Parus Major) During the Dawn Chorus

The Auk ◽  
2004 ◽  
Vol 121 (1) ◽  
pp. 184-191 ◽  
Author(s):  
Leen Gorissen ◽  
Marcel Eens
Keyword(s):  
Life Histories ◽  
Bird Species ◽  
Parus Major ◽  
Egg Laying ◽  
Interactive Communication ◽  
Dawn Chorus ◽  
Nest Box ◽  
Interactive Behavior ◽  
Song Birds ◽  
Dawn Song

Abstract Studies of the dawn chorus in birds have focused mainly on the behavior and song output of males and on the function(s) of male song. Less attention has been paid to the females' behavior and to communication between members of a pair. In Great Tits (Parus major), males sing vigorously at dawn in the vicinity of the female's nest hole just before and during egg laying. We studied the female's vocal behavior during the dawn chorus as well as communication between pair members. All females vocally interacted with their mates from inside the nest box. Females produced a sound with a very low sound-pressure level only audible from few meters, which we have named the “quiet call.” This quiet call was unique to females and was only produced from inside the nest box. To our knowledge, our study is the first to show that both members of a pair vocally interact during the dawn chorus. Given that many temperate-zone bird species have similar life histories as the Great Tit, it is very likely that similar interactive behavior occurs in other (song)birds. This interactive behavior may provide a new and manipulable tool for testing hypotheses about the dawn song and can be used as a future bioassay of male vocalizations.

scholarly journals Mass-dependent predation risk and lethal dolphin–porpoise interactions

2007 ◽  
Vol 274 (1625) ◽  
pp. 2587-2593 ◽  
Author(s):  
R MacLeod ◽  
C.D MacLeod ◽  
J.A Learmonth ◽  
P.D Jepson ◽  
R.J Reid ◽  
...  
Keyword(s):  
Predation Risk ◽  
Bottlenose Dolphins ◽  
Flight Performance ◽  
Energy Reserves ◽  
Trade Off ◽  
Fat Reserves ◽  
Ecological Principle ◽  
Mass Dependent ◽  
Starvation Risk ◽  
Individual Mass

In small birds, mass-dependent predation risk (MDPR) is known to make the trade-off between avoiding starvation and avoiding predation dependent on individual mass. This occurs because carrying increased fat reserves not only reduces starvation risk but also results in a higher predation risk due to reduced escape flight performance and/or the increased foraging exposure needed to maintain a higher body mass. In principle, the theory of MDPR could also apply to any animal capable of storing energy reserves to reduce starvation and whose escape performance decreases with increasing mass. We used a unique situation along certain parts of coastal Britain, where harbour porpoises ( Phocoena phocoena ) are pursued and killed but crucially not eaten by bottlenose dolphins ( Tursiops truncatus ), to investigate whether a MDPR effect can occur in non-avian species. We show that where high levels of dolphin ‘predation’ occur, porpoises carry significantly less energy reserves than would otherwise be expected and this equates to reducing by approximately 37% the length of time that a porpoise could survive without feeding. These results provide the first evidence that a mass-dependent starvation–predation risk trade-off may be a general ecological principle that can apply to widely different animal types rather than, as is currently thought, only to birds.

The Trade-Off Between Offspring Number and Quality in the Great Tit Parus major

10.2307/4837 ◽  
1989 ◽  
Vol 58 (2) ◽  
pp. 383 ◽  
Author(s):  
H. G. Smith ◽  
H. Kallander ◽  
J.-A. Nilsson
Keyword(s):  
Parus Major ◽  
Great Tit ◽  
Trade Off ◽  
Offspring Number
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