scholarly journals Trade-off between fertility and predation risk drives a geometric sequence in the pattern of group sizes in baboons

2018 ◽  
Vol 14 (3) ◽  
pp. 20170700 ◽  
Author(s):  
R. I. M. Dunbar ◽  
Padraig MacCarron ◽  
Cole Robertson
Keyword(s):  
Cluster Analysis ◽  
Predation Risk ◽  
Group Size ◽  
Group Living ◽  
Female Fertility ◽  
Access To Resources ◽  
Trade Off ◽  
Geometric Sequence ◽  
The Impact

Group-living offers both benefits (protection against predators, access to resources) and costs (increased ecological competition, the impact of group size on fertility). Here, we use cluster analysis to detect natural patternings in a comprehensive sample of baboon groups, and identify a geometric sequence with peaks at approximately 20, 40, 80 and 160. We suggest (i) that these form a set of demographic oscillators that set habitat-specific limits to group size and (ii) that the oscillator arises from a trade-off between female fertility and predation risk.

scholarly journals Group Size as a Trade Off Between Fertility and Predation Risk: Implications for Social Evolution

2018 ◽  
Author(s):  
R.I.M. Dunbar ◽  
Padraig Mac Carron
Keyword(s):  
Cluster Analysis ◽  
Predation Risk ◽  
Group Size ◽  
Social Evolution ◽  
Female Fertility ◽  
Fertility Rates ◽  
Trade Off ◽  
Lower Pair ◽  
Increase Group Size ◽  
Do So

AbstractCluster analysis reveals a fractal pattern in the sizes of baboon groups, with peaks at ∼20, ∼40, ∼80 and ∼160. Although all baboon species individually exhibit this pattern, the two largest are mainly characteristic of the hamadryas and gelada. We suggest that these constitute three pairs of linear oscillators (20/40, 40/80 and 80/160), where in each case the higher value is set by limits on female fertility and the lower by predation risk. The lower pair of oscillators form an ESS in woodland baboons, with choice of oscillator being determined by local predation risk. Female fertility rates would naturally prevent baboons from achieving the highest oscillator with any regularity; nonetheless, hamadryas and gelada have been able to break through this fertility ‘glass ceiling’ and we suggest that they have been able to do so by using substructuring (based partly on using males as ‘hired guns’). This seems to have allowed them to increase group size significantly so as to occupy higher predation risk habitats (thereby creating the upper oscillator).

Ecological drivers of group size in female Alpine chamois, Rupicapra rupicapra

Mammalia ◽  
2015 ◽  
Vol 79 (4) ◽  
Author(s):  
Roberta Chirichella ◽  
Andrea Mustoni ◽  
Marco Apollonio
Keyword(s):  
Predation Risk ◽  
Energy Intake ◽  
Group Size ◽  
Food Availability ◽  
Herd Size ◽  
Rupicapra Rupicapra ◽  
Trade Off ◽  
Mammalian Herbivores ◽  
Alpine Chamois

AbstractIn large mammalian herbivores, an increase in herd size not only reduces predation risk but also energy intake. As a consequence, the size of the groups made up by herbivores is often assumed to be the outcome of a trade-off depending on local predation risk and food availability. We studied Alpine chamois (

THE EFFECTIVENESS OF OPEN INNOVATION: DO SIZE AND PERFORMANCE OF OPEN INNOVATION GROUPS MATTER?

2017 ◽  
Vol 21 (03) ◽  
pp. 1750025
Author(s):  
EMMA L. HITCHEN ◽  
PETRA A. NYLUND ◽  
ERIC VIARDOT
Keyword(s):  
Group Size ◽  
Open Innovation ◽  
Conceptual Development ◽  
Positive Impact ◽  
Large Set ◽  
Trade Off ◽  
Innovative Performance ◽  
Positive Effects ◽  
Coordination Costs ◽  
The Impact

Innovation is accelerated by heterogeneous knowledge, which is obtained in open innovation. We investigate whether there are limits to the beneficial degree of openness. Conceiving innovator group size as a trade-off between knowledge heterogeneity and coordination costs for innovating groups, we theorise about the impact of group size on innovative performance. We hypothesise that openness and internationalisation positively moderate this relationship, but that the positive effects are limited by the trade-off between knowledge heterogeneity and coordination costs. Through an empirical investigation using a large set of international patent data, we find support for our conceptual development and are able to conclude how many individuals those groups contain that generate the most innovative performance. Groups of three inventors have the most positive impact, and groups of two to eight inventors also generate positive effects. Science-based industries however allow for bigger groups than other industries, and supplier-dominated industries have smaller beneficial group sizes.

Subjective Fear Dilutes as Group Size Increases

2020 ◽  
Author(s):  
dean mobbs ◽  
Ellen Tedeschi ◽  
Anastasia Buyalskaya ◽  
Brian Silston
Keyword(s):  
Group Size ◽  
Real World ◽  
Survival Benefit ◽  
Group Living ◽  
External Factors ◽  
Threat Perception ◽  
Perception Of Threat ◽  
Threat Level ◽  
Internal States ◽  
Risk Dilution

According to Hamilton’s Selfish Herd Theory, a crucial survival benefit of group living is that it provides a ‘risk dilution’ function against predation. Despite a large literature on group living benefits in animals, few studies have been conducted on how group size alters subjective fear or threat perception in humans, and on what factors drive preferences for being in groups when facing threats. We conducted seven experiments (N=3,838) to test (A) if the presence of others decreases perception of threat under a variety of conditions. In studies 1 to 3, we experimentally manipulated group size in hypothetical and real-world situations, to show that fear responses decreased as group size increased. In studies 4 to 7 we again used a combination of hypothetical, virtual and real-world decisions to test (B) how internal states (e.g. anxiety) and external factors (e.g. threat level, availability of help) affected participants’ preference for groups. Participants consistently chose larger groups when threat and anxiety were high. Overall, our findings show that group size provides a salient signal of protection and safety.

scholarly journals Retirement Age and Housing Consumption: The Case of South Korea

2021 ◽  
Vol 13 (3) ◽  
pp. 1286
Author(s):  
Chunil Kim ◽  
Hyobi Choi ◽  
Yeol Choi
Keyword(s):  
South Korea ◽  
Group Living ◽  
Peripheral Region ◽  
Housing Tenure ◽  
Housing Consumption ◽  
Household Expenditures ◽  
Housing Tenure Choice ◽  
Populated Region ◽  
The Impact ◽  
Real Assets

South Korea became an aging society in 2000 and will become a super-aged nation in 2026. The extended life expectancy and earlier retirement make workers’ preparation for retirement more difficult, and that hardship might lead to poorer living conditions after retirement. As annuity payments are, in general, not enough for retirees to maintain their previous standard of living after retirement, retired households would have to liquidate their financial and real assets to cover household expenditures. As housing takes the biggest share of households’ total assets in Korea, it seems to be natural for retirees to downsize their houses. However, there is no consensus in the housing literature on housing downsizing, and the debate is still ongoing. In order to understand whether or not housing downsizing by retirees occurs in Korea, this paper examines the impact of the timing of retirement on housing consumption using an econometric model of housing tenure choice and the consumption for housing. The results show that the early retirement group living in more populated region does not downsize the house, while the timing of retirement is negatively associated with housing consumption for the late retirement group living in the peripheral region.

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

scholarly journals Market buoyancy, information transparency and pricing strategy in the Scottish housing market

Urban Studies ◽  
2021 ◽  
pp. 004209802199178
Author(s):  
Nan Liu
Keyword(s):  
Pricing Strategy ◽  
Selling Price ◽  
Trade Off ◽  
Information Transparency ◽  
North East ◽  
Sealed Bid ◽  
Strategy Changes ◽  
The Impact ◽  
Role Of Information

In housing markets there is a trade-off between selling time and selling price, with pricing strategy being the balancing act between the two. Motivated by the Home Report scheme in Scotland, this paper investigates the role of information symmetry played in such a trade-off. Empirically, this study tests if sellers’ pricing strategy changes when more information becomes available and whether this, in turn, affects the trade-off between the selling price and selling time. Using housing transaction data of North-East Scotland between 1998Q2 and 2018Q2, the findings show that asking price has converged to the predicted price of the property since the introduction of the Home Report. While information transparency reduces the effect of ‘overpricing’ on selling time, there is little evidence to show that it reduces the impact of pricing strategy on the final selling price in the sealed-bid context.

Interrelationship Among Competition, Diversification and Liquidity Creation: Evidence from Indian Banks

2021 ◽  
Vol 15 (2) ◽  
pp. 183-204
Author(s):  
Pankaj Sinha ◽  
Naina Grover
Keyword(s):  
Inverse Relationship ◽  
Consumer Welfare ◽  
Adverse Impact ◽  
Public And Private ◽  
Jel Codes ◽  
Trade Off ◽  
Private Banks ◽  
Indian Banks ◽  
The Impact

This study analyses the impact of competition on liquidity creation by banks and investigates the dynamics between diversification, liquidity creation and competition for banks operating in India during the period from 2005 to 2018. Using the broad and narrow measures of liquidity creation, an inverse relationship is determined between liquidity creation and competition. The study also indicates a trade-off between pro-competitive policies to improve consumer welfare and the liquidity-destroying effects of competition, and it highlights how diversification affects liquidity creation. Highly diversified banks in India create less liquidity compared with less-diversified banks, both public and private. The liquidity-destroying effects of competition is intensified among highly diversified private banks, which suggest that diversification has not moderated the adverse impact of competition. JEL Codes: G01, G18, G21, G28

scholarly journals An approach to assess stress in response to drive hunts using cortisol levels of wild boar (Sus scrofa)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Justine Güldenpfennig ◽  
Marion Schmicke ◽  
Martina Hoedemaker ◽  
Ursula Siebert ◽  
Oliver Keuling
Keyword(s):  
Wild Boar ◽  
Stress Hormones ◽  
Age Groups ◽  
Group Living ◽  
Well Being ◽  
Lower Saxony ◽  
Cortisol Levels ◽  
Negative Impacts ◽  
The Impact ◽  
Effect Of Age

AbstractHunting can easily be linked to stress in wildlife. Drive hunts performed two to three times in one area during the respective hunting period, are thought to decrease the pressure hunting places on wildlife. Nevertheless, the expression of cortisol—one of the main mammalian stress hormones—is considered to have negative impacts on animals’ well-being if expressed excessively, which may occur during some (especially repeated) hunting events. We explored the effect of drive hunts on cortisol levels in wild boar in Lower Saxony, Germany, compared these cortisol levels to reference values given by a similar study, and investigated the effect of age, sex, and pregnancy. Blood collected from wild boar shot on drive hunts was analysed using a radioimmunoassay. As expected, we observed elevated cortisol levels in all samples, however, we still found significant differences between age groups and sexes, as well as an influence of pregnancy on cortisol levels. The effect of drive hunts on cortisol levels appears to be weaker than predicted, while the effects of other variables, such as sex, are distinct. Only half of the evaluated samples showed explicitly increased cortisol levels and no significant differences were found between sampling months and locations. Group living animals and pregnant females showed significantly higher cortisol levels. The impact of hunting is measurable but is masked by natural effects such as pregnancy. Thus, we need more information on stress levels in game species.

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