scholarly journals Co-evolved maternal effects selectively eliminate offspring depending on resource availability

2020 ◽  
Author(s):  
Bin-Yan Hsu ◽  
Martina S. Müller ◽  
Christoph L. Gahr ◽  
Cor Dijkstra ◽  
Ton G.G. Groothuis
Keyword(s):  
Experimental Evidence ◽  
Maternal Effects ◽  
Resource Availability ◽  
Detrimental Effect ◽  
Hatching Asynchrony ◽  
Chick Growth ◽  
Size Hierarchy ◽  
Food Conditions ◽  
Good Food ◽  
Maternal Testosterone

Many plants and animals adaptively downsize the number of already-produced propagules if resources become insufficient to raise all of them. In birds, mothers often induce hatching asynchrony by incubating first eggs before last eggs are laid, creating an age/size hierarchy within broods which selectively eliminates the smallest chicks in poor food conditions. However, mothers also deposit more testosterone into late-laid eggs, which boosts competitive abilities of younger chicks, counteracts the competitive hierarchy, and ostensibly creates a paradox. Since testosterone also carries costs, we hypothesized that benefits of maternally deposited testosterone outweigh its costs in good food conditions, but that testosterone has a net detrimental effect in poor food conditions. We found experimental evidence that elevated maternal testosterone in the egg caused higher chick mortality in poor food conditions but better chick growth in good food conditions. These context-dependent effects resolve the paradox, suggesting co-evolution of two maternal effects, and explain inconsistent results of egg hormone manipulations in the literature.

Resource availability, maternal effects, and longevity

1983 ◽  
Vol 18 (2) ◽  
pp. 147-165 ◽  
Author(s):  
Michael Lynch ◽  
Richard Ennis
Keyword(s):  
Maternal Effects ◽  
Resource Availability

Incomplete milking has no detectable effect on somatic cell count but increased cell count appears to increase strip yield

2008 ◽  
Vol 48 (9) ◽  
pp. 1161 ◽  
Author(s):  
T. Clarke ◽  
E. M. Cuthbertson ◽  
R. K. Greenall ◽  
M. C. Hannah ◽  
D. Shoesmith
Keyword(s):  
Somatic Cell ◽  
Experimental Evidence ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Detrimental Effect ◽  
Labour Productivity ◽  
Detectable Effect ◽  
Common Belief ◽  
Popular Belief

Milking regimes that can greatly shorten the milking duration of slow-milking cows to improve labour productivity can also result in less complete milking for some cows. There is also a common belief and limited experimental evidence that incomplete milking of subclinically infected cows can cause increased somatic cell count (SCC). To test for this possible detrimental effect of shorter milking regimes, ‘complete’ milking [to automatic cluster remover (ACR) setting of 300 mL/min] and ‘incomplete’ milking (to an ACR setting of 800 mL/min) were applied sequentially to 45 cows over 7 weeks. Incomplete milking resulted in an average of 0.3 L of extra milk being left in the udders, but there was no significant increase in quarter SCC in either infected or uninfected udder quarters. Change in SCC was not related to change in strip yield induced by incomplete milking treatment. In contrast, cow strip yield was positively related to SCC, or the number of infected quarters/cow, regardless of the applied ACR treatment. These apparently contradictory findings are reconciled by noting that infection causes both high strip yields (via uneven yielding quarters) and high SCC. It is concluded that, contrary to popular belief, high SCC, as an indicator of infection, causes high strip yield and that increasing strip yield does not increase cell count.

scholarly journals Maternal programming of offspring in relation to food availability in an insect ( Forficula auricularia )

2016 ◽  
Vol 283 (1828) ◽  
pp. 20152936 ◽  
Author(s):  
Shirley Raveh ◽  
Dominik Vogt ◽  
Mathias Kölliker
Keyword(s):  
Food Availability ◽  
Maternal Effects ◽  
Developmental Rate ◽  
High Food ◽  
Forficula Auricularia ◽  
Matching Effect ◽  
Food Conditions ◽  
The One ◽  
Size Adjustment ◽  
European Earwig

Maternal effects can induce adjustments in offspring phenotype to the environment experienced by the mother. Of particular interest is if mothers can programme their offspring to cope best under matching environmental conditions, but the evidence for such anticipatory maternal effects (AME) is limited. In this study, we manipulated experimentally the food availability experienced by mothers and their offspring in the European earwig ( Forficula auricularia ). Offspring produced by females that had access to high or low food quantities were cross-fostered to foster mothers experiencing matched or mismatched environments. Offspring experiencing food availability matching the one of their mothers had an increased survival to adulthood compared with offspring experiencing mismatched conditions. Females experiencing high food laid larger clutches. This clutch-size adjustment statistically explained the matching effect when offspring experienced high food, but not when experiencing low food conditions. There were no effects of matching on offspring growth and developmental rate. Overall, our study demonstrates that AME occurs in relation to food availability enhancing offspring survival to adulthood under matching food conditions.

scholarly journals Speciation in caves: experimental evidence that permanent darkness promotes reproductive isolation

2011 ◽  
Vol 7 (6) ◽  
pp. 909-912 ◽  
Author(s):  
Rüdiger Riesch ◽  
Martin Plath ◽  
Ingo Schlupp
Keyword(s):  
Reproductive Isolation ◽  
Experimental Evidence ◽  
Abiotic Factors ◽  
Common Garden ◽  
Food Treatment ◽  
Poecilia Mexicana ◽  
Columnaris Disease ◽  
Selective Forces ◽  
Food Conditions ◽  
Surface Dwelling

Divergent selection through biotic factors like predation or parasitism can promote reproductive isolation even in the absence of geographical barriers. On the other hand, evidence for a role of adaptation to abiotic factors during ecological speciation in animals is scant. In particular, the role played by perpetual darkness in establishing reproductive isolation in cave animals (troglobites) remains elusive. We focused on two reproductively isolated ecotypes (surface- and cave-dwelling) of the widespread livebearer Poecilia mexicana , and raised offspring of wild-caught females to sexual maturity in a 12-month common-garden experiment. Fish were reared in light or darkness combined with high- or low-food conditions. Females, but not males, of the surface ecotype suffered from almost complete reproductive failure in darkness, especially in the low-food treatment. Furthermore, surface fish suffered from a significantly higher rate of spontaneous, stress-related infection with bacterial columnaris disease. This experimental evidence for strong selection by permanent darkness on non-adapted surface-dwelling animals adds depth to our understanding of the selective forces establishing and maintaining reproductive isolation in cave faunas.

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.

Hatching asynchrony and offspring sex: an experiment on maternal effects in the yellow-legged gull

2011 ◽  
Vol 23 (4) ◽  
pp. 300-317 ◽  
Author(s):  
N. Saino ◽  
M. Romano ◽  
M. Caprioli ◽  
R. Ambrosini ◽  
D. Rubolini ◽  
...  
Keyword(s):  
Maternal Effects ◽  
Hatching Asynchrony ◽  
Offspring Sex

Competition and Price Transparency in the Market for Lemons: Experimental Evidence

2021 ◽  
Vol 13 (2) ◽  
pp. 113-140
Author(s):  
Olivier Bochet ◽  
Simon Siegenthaler
Keyword(s):  
Asymmetric Information ◽  
Experimental Evidence ◽  
Detrimental Effect ◽  
Conditional Reasoning ◽  
Strategy Method ◽  
Price Transparency ◽  
Enhancing Effect ◽  
Market For Lemons ◽  
Theoretical Predictions ◽  
The Impact

In markets with asymmetric information, where equilibria are often inefficient, bargaining can help promote welfare. We design an experiment to examine the impact of competition and price transparency in such settings. Consistent with the theoretical predictions, we find that competition promotes efficiency if bargainers cannot observe each other’s price offers. Contrary to the predictions, however, the efficiency-enhancing effect of competition persists even when offers are observable. We explore different behavioral explanations for the absence of a detrimental effect of price transparency. Remarkably, implementing the strategy method improves subjects’ conditional reasoning, delivering the predicted loss in efficiency when offers are observable. (JEL C78, D82, L15)

Clutch Size of Kestrels: Seasonal Decline and Experimental Evidence for Food Limitation under Fluctuating Food Conditions

Oikos ◽  
1998 ◽  
Vol 83 (2) ◽  
pp. 259 ◽  
Author(s):  
Erkki Korpimäki ◽  
Jürgen Wiehn ◽  
Erkki Korpimaki ◽  
Jurgen Wiehn
Keyword(s):  
Experimental Evidence ◽  
Clutch Size ◽  
Food Limitation ◽  
Food Conditions ◽  
Seasonal Decline

scholarly journals Chick Growth and Breeding Success of the Burrowing Parrot

The Condor ◽  
2002 ◽  
Vol 104 (3) ◽  
pp. 574-586 ◽  
Author(s):  
Juan F. Masello ◽  
Petra Quillfeldt
Keyword(s):  
Breeding Success ◽  
Growth Parameters ◽  
Large Mass ◽  
Hatching Asynchrony ◽  
Brood Reduction ◽  
Egg Mass ◽  
Chick Growth ◽  
Large Variability ◽  
Rio Negro ◽  
Nestling Period

Abstract We present the first data on the breeding biology of wild Burrowing Parrots (Cyanoliseus patagonus). We studied chick growth and breeding success at the largest colony of the species in the province of Río Negro, Patagonia, Argentina, during the 1999–2000 breeding season. A very high fledging success was observed and related to the absence of nest predation and the colonial breeding system. Safe nest sites were also thought to favor large mass recession of the nestlings before fledging. Mortality during the nestling period tended to be higher for fourth and fifth nestlings of a brood, indicating that brood reduction occurred. Burrowing Parrots in the study colony showed large variability in growth parameters between nestlings, possibly related to the hatching asynchrony observed. Allometric relationships for egg mass, clutch size, relative clutch mass, and nestling period of 29 wild psittaciform species are described and compared with the data from the Burrowing Parrots. Desarrollo de los Pichones y Éxito de Nidificación de Cyanoliseus patagonus Resumen. Presentamos aquí los primeros datos de la biología reproductiva en estado silvestre del loro Cyanoliseus patagonus. Se estudió el crecimiento de los pichones y el éxito de nidificación en la colonia más importante de la especie (provincia de Río Negro, Patagonia, Argentina) durante la temporada de cría 1999–2000. Se observó un alto éxito de emplumamiento de los pichones relacionado a la ausencia de depredación en el nido y al sistema colonial de nidificación que presenta la especie. Los sitios de nidificación seguros habrían favorecido la pronunciada pérdida de masa corporal observada en los pichones antes de abandonar el nido. La mortalidad durante el período de nidificación tendió a ser más alta para el cuarto y quinto pichón de la nidada, indicando la existencia de reducción de la camada. Los loros de la colonia estudiada mostraron gran variabilidad en los parámetros de desarrollo de los distintos pichones, estando ésto posiblemente relacionado con el nacimiento asincrónico de los pichones. Se describen también relaciones alométricas para la masa del huevo, el tamaño de la nidada, la masa relativa de la nidada y el período de permanencia en el nido de 29 psittaciformes silvestres y se comparan con los datos de C. patagonus.

Sign in / Sign up

Export Citation Format

Share Document