On the Adaptive Value of Intraclutch Egg-Size Variation in Birds

The Auk ◽  
1984 ◽  
Vol 101 (4) ◽  
pp. 685-697 ◽  
Author(s):  
Tore Slagsvold ◽  
Jostein Sandvik ◽  
Gunnar Rofstad ◽  
Öystein Lorentsen ◽  
Magne Husby
Keyword(s):  
Egg Size ◽  
Negative Relationship ◽  
Size Variation ◽  
Brood Reduction ◽  
Survival Strategy ◽  
Reduction Strategy ◽  
Adaptive Value ◽  
Using Data ◽  
D Values ◽  
Interspecific Comparisons

AbstractUsing data from the field and the literature on 67 species of birds, we analyzed intraclutch variation in egg size, especially the deviation of the last egg from the clutch mean (D). Values of D are closer to zero in precocial than in altricial species; D is negatively correlated with body size in interspecific comparisons, i.e. large birds, including precocial species, lay small final eggs; and D is higher in open-nesting passerines (on average D = +3.56%, 17 species) than in hole-nesting species (on average D = -0.05%, 13 species). Within populations of birds, a negative relationship exists between D and clutch size, particularly in species that have a generally low value of D. The results support the view that intraclutch variation in egg size has an ultimate, adaptive value. We suggest that birds adopting the "brood-reduction strategy" have a small final egg, particularly those birds with large clutches, whereas birds adopting the "brood-survival strategy" have a relatively large final egg, particularly those birds with large clutches.

Egg size and clutch size in three species of Nihonotrypaea (Decapoda: Thalassinidea: Callianassidae) from western Kyushu, Japan

2006 ◽  
Vol 86 (1) ◽  
pp. 103-111 ◽  
Author(s):  
K. Kubo ◽  
K. Shimoda ◽  
A. Tamaki
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Relative Size ◽  
Size Variation ◽  
Middle Part ◽  
Reproductive Period ◽  
Late Winter ◽  
Estuarine System ◽  
Ariake Sound ◽  
Interspecific Comparisons

Three species of the callianassid genus Nihonotrypaea occur in the Ariake Sound estuarine system, southern Japan; they consist of two tidal-flat species (N. harmandi; N. japonica) and one boulder-beach species (N. petalura), with maximum population densities of 1440, 343, and 12 ind m−2, respectively. Nihonotrypaea harmandi and N. petalura are distributed along the coastline from the outermost part of the sound to the open sea, while N. japonica occurs in the middle part of the sound. Nihonotrypaea japonica has an extended reproductive period from late winter to autumn, while those of the other species are from late spring or summer to autumn. Interspecific comparisons were made for recently laid egg size (as volume) and clutch size (as number of eggs per female). Only in N. japonica was a seasonal egg size variation observed, being significantly larger in winter to spring (mean=0.106 mm3) than in summer (0.080 mm3). By contrast, clutch size was significantly smaller in winter to spring, resulting in nearly the same clutch volume per female (product of the mean egg volume and clutch size) between the seasons. Among the three species, the egg size was ordered as N. japonica (overall mean volume through the seasons=0.092 mm3)>>N. petalura (0.057 mm3)>N. harmandi (0.054 mm3). The clutch size was ordered as N. harmandi>N. petalura≈N. japonica. The clutch volume was ordered as N. japonica≈N. harmandi>N. petalura. The smallest clutch volume value for N. petalura female showed an opposite trend to the relative size of the major cheliped found in a previous study.

scholarly journals Migratory constraints on yolk precursors limit yolk androgen deposition and underlie a brood reduction strategy in rockhopper penguins

2012 ◽  
Vol 8 (6) ◽  
pp. 1055-1058 ◽  
Author(s):  
Glenn T. Crossin ◽  
Maud Poisbleau ◽  
Laurent Demongin ◽  
Olivier Chastel ◽  
Tony D. Williams ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Maternal Effects ◽  
Egg Size ◽  
Hatching Asynchrony ◽  
Brood Reduction ◽  
Size Dimorphism ◽  
Reduction Strategy ◽  
Yolk Androgens ◽  
Linear Relationships ◽  
Androgen Levels

Hormonally mediated maternal effects link maternal phenotype and environmental conditions to offspring phenotype. The production of lipid-rich maternal yolk precursors may provide a mechanism by which lipophilic steroid hormones can be transported to developing yolks, thus predicting a positive correlation between yolk precursors in mothers and androgen levels in eggs. Using rockhopper penguins ( Eudyptes chrysocome ), which produce a two-egg clutch characterized by extreme egg-size dimorphism, reversed hatching asynchrony and brood-reduction, we examined correlations between circulating concentrations of the primary yolk-precursor vitellogenin (VTG) and levels of yolk androgens. Previous work in Eudyptes penguins has shown that egg-size dimorphism is the product of migratory constraints on yolk precursor production. We predicted that if yolk precursors are constrained, androgen transport to developing yolks would be similarly constrained. We reveal positive linear relationships between maternal VTG and androgens in small A-eggs but not larger B-eggs, which is consistent with a migratory constraint operating on the A-egg. Results suggest that intra-clutch variation in total yolk androgen levels depends on the production and uptake of yolk precursors. The brood reduction strategy common to Eudyptes might thus be best described as the result of a migratory constraint.

scholarly journals Condition dependent strategies of egg size variation in the Common Eider Somateria mollissima

2019 ◽  
Author(s):  
Thomas Kjær Christensen ◽  
Thorsten Johannes Skovbjerg Balsby
Keyword(s):  
Clutch Size ◽  
Body Condition ◽  
Egg Size ◽  
Size Variation ◽  
Common Eider ◽  
Somateria Mollissima ◽  
Individual Level ◽  
Laying Sequence ◽  
The Common ◽  
Using Data

AbstractWe analysed intraclutch egg-size variation in relation to clutch size and to female body condition in the Common Eider Somateria mollissima during an 8-year period. The aim was to assess if eiders adaptively adjusted egg size within the laying sequence in response to different clutch sizes, which potentially could optimise reproductive success through a size advantage in hatchlings. The analyses were performed on both population and individual level using data from recaptured females that changed clutch size between seasons. Based on 1,099 clutches from 812 individual females, population clutch size averaged 4.13 eggs (range: 1-6), with marked annual variation in the dominance of 4- and 5-egg clutches, which constituted c.70% of all clutches. Clutch size was positively related to female pre-laying body condition at both the population and individual level. Egg size varied significantly within and between clutch sizes and changes were significantly related to the laying sequence. First eggs were significantly larger in 4-egg clutches and second eggs smaller (marginally insignificant) than in 5-egg clutches, a pattern also found among individual females changing clutch size between seasons. The relationship between female pre-laying body condition, clutch size and the intraclutch egg-size pattern indicates that both clutch size and egg size is actively adapted to the pre-breeding body condition of the female. We suggest that the observed pattern of intraclutch egg-size variation reflects a finely tuned conditional dependent mechanisms that enable females in a suboptimal condition to optimize reproductive output.

Is the bottom line reached? An exploration of supervisor bottom-line mentality, team performance avoidance goal orientation and team performance

2021 ◽  
pp. 001872672110029
Author(s):  
Yuying Lin ◽  
Mengxi Yang ◽  
Matthew J Quade ◽  
Wansi Chen
Keyword(s):  
Goal Orientation ◽  
Team Performance ◽  
Social Information Processing ◽  
Negative Relationship ◽  
Bottom Line ◽  
Team Members ◽  
Processing Theory ◽  
Using Data ◽  
Exclusive Focus ◽  
Avoidance Goal

How do supervisors who treat the bottom line as more important than anything else influence team success? Drawing from social information processing theory, we explore how and when supervisor bottom-line mentality (i.e. an exclusive focus on bottom-line outcomes at the expense of other priorities) exerts influence on the bottom-line itself, in the form of team performance. We argue that a supervisor’s bottom-line mentality provides significant social cues for the team that securing bottom-line objectives is of sole importance, which stimulates team performance avoidance goal orientation, and thus decreases team performance. Further, we argue performing tension (i.e. tension between contradictory needs, demands, and goals), serving as team members’ mutual perception of the confusing environment, will strengthen the indirect negative relationship between supervisor bottom-line mentality and team performance through team performance avoidance goal orientation. We conduct a path analysis using data from 258 teams in a Chinese food-chain company, which provides support for our hypotheses. Overall, our findings suggest that supervisor’s exclusive focus on the bottom-line can serve to impede team performance. Theoretical contributions and practical implications are discussed.

scholarly journals Does Corruption Lead to Lower Subnational Credit Ratings? Fiscal Dependence, Market Reputation, and the Cost of Debt

2021 ◽  
pp. 1-19
Author(s):  
Maciej Sychowiec ◽  
Monika Bauhr ◽  
Nicholas Charron
Keyword(s):  
Credit Ratings ◽  
National Level ◽  
Negative Relationship ◽  
Cost Of Debt ◽  
Economic Implications ◽  
Sovereign Credit Ratings ◽  
Heterogeneous Effects ◽  
Federal Revenue ◽  
Negative Effect ◽  
Using Data

Abstract While studies show a consistent negative relationship between the level of corruption and range indicators of national-level economic performance, including sovereign credit ratings, we know less about the relationship between corruption and subnational credit ratings. This study suggests that federal transfers allow states with higher levels of corruption to retain good credit ratings, despite the negative economic implications of corruption more broadly, which also allows them to continue to borrow at low costs. Using data on corruption conviction in US states and credit ratings between 2001 and 2015, we show that corruption does not directly reduce credit ratings on average. We find, however, heterogeneous effects, in that there is a negative effect of corruption on credit ratings only in states that have a comparatively low level of fiscal dependence on federal transfers. This suggest that while less dependent states are punished by international assessors when seen as more corrupt, corruption does not affect the ratings of states with higher levels of fiscal dependence on federal revenue.

Workplace disability and job satisfaction in Britain: A co-worker test?

2021 ◽  
pp. 0143831X2110142
Author(s):  
Getinet Astatike Haile
Keyword(s):  
Job Satisfaction ◽  
Negative Relationship ◽  
Organisational Culture ◽  
Seemingly Unrelated Regression ◽  
Unrelated Regression ◽  
Significant Negative Relationship ◽  
Using Data

The article examines the link between workplace disability (WD) and workplace job satisfaction (JS) using data from WERS2011. Controlling for a rich set of workplace characteristics including organisational culture, the study finds a significant negative relationship between JS and the share of disabled respondents within workplaces. Notably, Seemingly Unrelated Regression (SUR)-based analysis distinguishing between disabled and non-disabled respondents reveals that the negative relationship found is specific to non-disabled respondents. Moreover, disability equality policies are found to be significantly positively related with disabled respondents’ JS while they are negatively related with the JS of their non-disabled counterparts. The article ponders if there is a co-worker aspect to the WD–JS link and whether HR policies may need to take heed of co-worker dynamics in this respect.

scholarly journals The relationship between inter-organizational trust and performance

2012 ◽  
Vol 60 (4) ◽  
pp. 89-98 ◽  
Author(s):  
Roman Fiala ◽  
Martin Prokop ◽  
Iva Živělová
Keyword(s):  
Structural Equation ◽  
Organizational Trust ◽  
Negative Relationship ◽  
Fit Indices ◽  
Supplier Performance ◽  
Significant Negative Relationship ◽  
Model Fit Indices ◽  
And Performance ◽  
Using Data ◽  
The Relationship

The article deals with an investigation of the relationship between inter-organizational trust and performance. Using data obtained in a questionnaire survey in 373 organizations with more than 20 employees with their seat in the Czech Republic, we found the relationship between inter-organizational trust and supplier performance, mediated by the level of conflict. Also, the statistically significant negative relationship between inter-organizational trust and costs of negotiation and the statistically significant positive relationship between supplier performance and perceived performance were confirmed. The hypothesis on the statistically significant relationship between inter-organizational trust and negotiating costs was not confirmed. The structural equation modelling technique was used in the calculations. The calculated model fit indices (CFI, NFI, NNFI) with values over 0.9 demonstrate a very good quality of the model.

scholarly journals Effects of Environmental Conditions and Parental Quality on Inter- and Intraclutch Egg-Size Variation in the Collared Flycatcher (Ficedula Albicollis)

The Auk ◽  
2005 ◽  
Vol 122 (2) ◽  
pp. 509-522 ◽  
Author(s):  
Rita Hargitai ◽  
János Török ◽  
László Tóth ◽  
Gergely Hegyi ◽  
Balázs Rosivall ◽  
...  
Keyword(s):  
Egg Size ◽  
Size Variation ◽  
Laying Date ◽  
Life History Trait ◽  
Ficedula Albicollis ◽  
Collared Flycatcher ◽  
Egg Formation ◽  
Adaptive Explanation ◽  
Breeding Condition

AbstractEgg size is a particularly important life-history trait mediating maternal influences on offspring phenotype. Females can vary their egg-size investment in relation to environmental circumstances, their own breeding condition, and the quality of their mate. Here we analyzed inter- and intraclutch variation in egg size in the Collared Flycatcher (Ficedula albicollis) on the basis of eight years of data. According to our results, mean egg size increased with female condition, but did not differ among young, middle-aged, and old females. The male’s age, body size, and forehead patch size did not influence egg size; thus, we found no evidence for differential investment in egg size in relation to male quality. We found no effect of laying date on egg size when controlling for ambient temperature during the egg formation period, yet temperature had a significant effect on egg size. That result indicates proximate constraints on egg formation. Furthermore, we report on annual differences in intraclutch egg-size variation. Egg size increased within clutches in years with a warm prelaying period; whereas in years when the weather during that period was cold, there was no significant intraclutch trend. Proximate considerations seem to explain the observed patterns of intraclutch egg-size variation; however, we cannot reject the adaptive explanation. Mean egg size and intraclutch egg-size variation were unrelated to clutch size. Therefore, we found no evidence for a trade-off between size and number of eggs within a clutch.

Relationship Quality Among Older Cohabitors: A Comparison to Remarrieds

2019 ◽  
Vol 75 (8) ◽  
pp. 1808-1817
Author(s):  
Matthew R Wright
Keyword(s):  
Relationship Quality ◽  
Positive Relationship ◽  
Negative Relationship ◽  
Later Life ◽  
Well Being ◽  
Poor Quality ◽  
Two Measures ◽  
Using Data ◽  
Union Type ◽  
Quality Relationships

Abstract Objectives Later life marital patterns have undergone shifts over the past few decades, including a rapid growth of cohabiting unions. Despite the increase in older adult cohabitation, research on this population has been slow to keep up. Intimate relationships are linked to well-being and relationship quality is especially important because high-quality relationships offer a number of benefits for well-being, whereas poor-quality relationships often are detrimental. This study compares cohabiting and remarried individuals on two measures of relationship quality. Method Using data from the 2010 and 2012 Health and Retirement Study, I investigate the positive and negative relationship quality of cohabitors relative to their remarried counterparts and whether the association of union type and relationship quality varies by race. Results Across both positive and negative relationship quality, I found few differences between cohabiting and remarried individuals. Black cohabitors report higher positive relationship quality than remarrieds, whereas White cohabitors and remarrieds do not differ. Discussion These findings suggest that cohabiting unions and remarriages are comparable among White older adults, but that Black cohabitors may gain more in terms of positive relationship quality than their remarried counterparts.

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