Do Great Tits Adjust Hatching Spread, Egg Size and Offspring Sex Ratio to Changes in Clutch Size?

10.2307/5318 ◽  
1992 ◽  
Vol 61 (2) ◽  
pp. 249 ◽  
Author(s):  
Tore Slagsvold ◽  
Trond Amundsen
Keyword(s):  
Sex Ratio ◽  
Clutch Size ◽  
Egg Size ◽  
Offspring Sex Ratio ◽  
Offspring Sex

scholarly journals Offspring sex ratio varies with clutch size for female house wrens induced to lay supernumerary eggs

2013 ◽  
Vol 25 (1) ◽  
pp. 165-171 ◽  
Author(s):  
E. K. Bowers ◽  
C. F. Thompson ◽  
S. K. Sakaluk
Keyword(s):  
Sex Ratio ◽  
Clutch Size ◽  
Offspring Sex Ratio ◽  
House Wrens ◽  
Offspring Sex

scholarly journals Female manipulation of offspring sex ratio in the gregarious parasitoidAnaphes flavipesfrom a new two-generation approach

2021 ◽  
Author(s):  
Alena Samková ◽  
Jan Raška ◽  
Jiří Hadrava ◽  
Jiří Skuhrovec ◽  
Petr Janšta
Keyword(s):  
Sex Ratio ◽  
Clutch Size ◽  
Empirical Work ◽  
External Factors ◽  
Offspring Sex Ratio ◽  
Future Fertility ◽  
Offspring Sex ◽  
Body Sizes ◽  
F2 Generation ◽  
F1 Generation

ABSTRACTBoth theoretical and empirical work suggests that offspring sex ratio has important consequences on fitness. Within insects, gregarious parasitoids with haplodiploid sex determination represent an ideal model for studying the decision-making process behind the assignment of offspring sex. To gain insight into the offspring sex ratio of gregarious parasitoids, we performed experiments onAnaphes flavipes, interpreting our results through a two-generation approach. We confirm the existence of a relationship between offspring sex ratio and clutch size: the proportion of males increases with larger clutch size. Based on this finding, we assumed that the proportion of males among one female’s offspring would also increase with external factors such as a low population density of the host or the presence of the host’s predator, which may pressure the mothers to lay a higher-sized clutch. Contrary to our initial expectations, we show that if it is the pressure of external factors that leads to an increase in clutch size, these larger clutches tend to be more female-biased and the overall offspring sex ratio of a particular female does not change. While in our previous work, we showed that higher clutch sizes reduce body sizes of the offspring and their future fertility, here we conclude that the differences in fertility affect the offspring sex ratio. Taken together, we highlight our two-generation approach which reveals that while the above external factors do not affect the sex ratio ofA. flavipesin the F1 generation, they do have an effect in the F2 generation.

Offspring sex ratio in moose Alces alces in relation to paternal age: an experiment

2004 ◽  
Vol 10 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Bernt-Erik Sæther ◽  
Erling J. Solberg ◽  
Morten Heim ◽  
John E. Stacy ◽  
Kjetill S. Jakobsen ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Alces Alces ◽  
Paternal Age ◽  
Offspring Sex Ratio ◽  
Offspring Sex

Breeding system can affect the offspring sex ratio in Syrian hamsters

2011 ◽  
Vol 45 (1) ◽  
pp. 55-57 ◽  
Author(s):  
M O M Chelini ◽  
N L Souza ◽  
E Otta
Keyword(s):  
Sex Ratio ◽  
Breeding System ◽  
Offspring Sex Ratio ◽  
Syrian Hamsters ◽  
Offspring Sex

scholarly journals Is biasing offspring sex ratio adaptive? A test of Fisher's principle across multiple generations of a wild mammal in a fluctuating environment

2018 ◽  
Vol 285 (1891) ◽  
pp. 20181251 ◽  
Author(s):  
Andrea E. Wishart ◽  
Cory T. Williams ◽  
Andrew G. McAdam ◽  
Stan Boutin ◽  
Ben Dantzer ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Offspring Sex Ratio ◽  
Offspring Sex ◽  
Adult Sex Ratio ◽  
Secondary Sex Ratio ◽  
North American Red Squirrels ◽  
Negative Frequency Dependent Selection ◽  
Fisher’S Principle

Fisher's principle explains that population sex ratio in sexually reproducing organisms is maintained at 1 : 1 owing to negative frequency-dependent selection, such that individuals of the rare sex realize greater reproductive opportunity than individuals of the more common sex until equilibrium is reached. If biasing offspring sex ratio towards the rare sex is adaptive, individuals that do so should have more grandoffspring. In a wild population of North American red squirrels ( Tamiasciurus hudsonicus ) that experiences fluctuations in resource abundance and population density, we show that overall across 26 years, the secondary sex ratio was 1 : 1; however, stretches of years during which adult sex ratio was biased did not yield offspring sex ratios biased towards the rare sex. Females that had litters biased towards the rare sex did not have more grandoffspring. Critically, the adult sex ratio was not temporally autocorrelated across years, thus the population sex ratio experienced by parents was independent of the population sex ratio experienced by their offspring at their primiparity. Expected fitness benefits of biasing offspring sex ratio may be masked or negated by fluctuating environments across years, which limit the predictive value of the current sex ratio.

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