scholarly journals A Sex Allocation Theory for Vertebrates: Combining Local Resource Competition and Condition‐Dependent Allocation

2007 ◽  
Vol 170 (5) ◽  
pp. E112-E128 ◽  
Author(s):  
Geoff Wild ◽  
Stuart A. West
Keyword(s):  
Sex Allocation ◽  
Resource Competition ◽  
Local Resource Competition ◽  
Local Resource ◽  
Sex Allocation Theory

Local resource competition affects sex allocation in a bird: experimental evidence

2016 ◽  
Vol 121 ◽  
pp. 157-162 ◽  
Author(s):  
Zitan Song ◽  
Yingqiang Lou ◽  
Yiping Hu ◽  
Qiuxiang Deng ◽  
Wei Gao ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Sex Allocation ◽  
Resource Competition ◽  
Local Resource Competition ◽  
Local Resource

Sex-Ratio Variation in Marsupials

1989 ◽  
Vol 37 (3) ◽  
pp. 467 ◽  
Author(s):  
A Cockburn
Keyword(s):  
Sex Ratio ◽  
High Frequency ◽  
Sex Allocation ◽  
Resource Competition ◽  
Data Sets ◽  
Current Interest ◽  
Local Resource Competition ◽  
Mode Of Reproduction ◽  
Local Resource ◽  
Data Dredging

Many marsupials produce sex ratios biased towards male or female young. In several cases these changes are comfortably accommodated in the existing theory of sex allocation. Local resource competition and the Trivers-Willard hypothesis have been usefully applied to several data sets, and preliminary experimental work has supported the main tenets of theory. By contrast, several data sets lack explanation, and provide challenges to theoreticians. The high frequency of bias in marsupials does not result from data-dredging, as bias is usually reported in descriptive accounts of marsupial reproduction, without recourse to any theoretical or mechanistic explanations. It is not possible to distinguish whether the marsupial mode of reproduction is well suited to manipulate sex allocation, or whether it facilitates measurement of biased sex allocation. As for most eutherians and birds, the mechanism of prenatal sex allocation is unknown for any marsupial. However, the current interest in sex-determining mechanisms in marsupials suggests a profitable avenue for collaboration between geneticists, physiologists and evolutionary ecologists.

scholarly journals Sex allocation in response to local resource competition over breeding territories

2009 ◽  
Vol 20 (2) ◽  
pp. 335-339 ◽  
Author(s):  
Mårten B. Hjernquist ◽  
Katherine A. Thuman Hjernquist ◽  
Jukka T. Forsman ◽  
Lars Gustafsson
Keyword(s):  
Sex Allocation ◽  
Resource Competition ◽  
Local Resource Competition ◽  
Local Resource

Sex Ratio and Local Resource Competition in a Prosimian Primate

Science ◽  
1978 ◽  
Vol 201 (4351) ◽  
pp. 163-165 ◽  
Author(s):  
A. B. CLARK
Keyword(s):  
Sex Ratio ◽  
Resource Competition ◽  
Local Resource Competition ◽  
Local Resource

scholarly journals Peregrine Falcon Eggs: Egg Size, Hatchling Sex, and Clutch Sex Ratios

The Condor ◽  
2003 ◽  
Vol 105 (2) ◽  
pp. 327-335 ◽  
Author(s):  
William Burnham ◽  
Calvin Sandfort ◽  
James R. Belthoff
Keyword(s):  
New Mexico ◽  
Egg Size ◽  
Resource Competition ◽  
Sex Ratios ◽  
Peregrine Falcon ◽  
Falco Peregrinus ◽  
Local Resource Competition ◽  
Local Resource ◽  
Peregrine Falcons ◽  
Falco Peregrinus Anatum

AbstractEggs (n = 367) collected from wild Peregrine Falcon (Falco peregrinus anatum) nests between 1976 and 1990 in Colorado and New Mexico were artificially incubated and hatched. We retrospectively examined these data for variation in egg length, breadth, and initial mass of hatchlings to resolve questions about relationships among egg size, chick size, and sex; and egg size related to first and second clutches and years. Egg length and breadth were significantly related to chick mass at hatching. Neither egg size nor hatchling mass were related to sex. Egg breadth slightly increased and then decreased over the years eggs were collected, which possibly reflects a re-established and then aging wild falcon population or other environmental variation. We also evaluated clutch sex ratios relative to theory based on sexual size dimorphism and local resource competition. Sex ratios did not significantly differ from 1:1 within first or second clutches separately or when combined. Thus, Peregrine Falcons in this population apparently did not skew clutch sex ratios in accordance with local resource competition or Fisherian theory.Huevos de Halcones Peregrinos: Tamaño, Sexo de los Pichones y Proporción de Sexos en la NidadaResumen. Huevos (n = 367) colectados de nidos silvestres de halcones peregrinos (Falco peregrinus anatum) entre 1976 y 1990 en Colorado y New Mexico fueron incubados artificialmente hasta eclosionar. Examinamos esos datos retrospectivamente en cuanto a la variación en la longitud y ancho del huevo y el peso inicial de los pichones para contestar preguntas sobre las relaciones entre tamaño del huevo, tamaño del pichón y sexo, y entre el tamaño del huevo con relación a primeras y segundas nidadas y años. La longitud y el ancho del huevo estuvieron significativamente relacionados con la masa del pichón al eclosionar. El tamaño del huevo y el peso del pichón no estuvieron relacionados con el sexo. El ancho de los huevos aumentó ligeramente y luego disminuyó a través de los años en que los huevos se colectaron, lo que posiblemente refleja una población silvestre de halcones re-establecida y posteriormente senescente, u otro tipo de variación ambiental. También evaluamos la proporción de sexos en las nidadas con relación a la teoría basada en el dimorfismo sexual de tamaño y la competencia local por recursos. Las proporciones de sexos no difirieron significativamente de 1:1 entre primeras o segundas nidadas separadamente o de forma combinada. Por tanto, los halcones peregrinos en esta población aparentemente no sesgaron la proporción de sexos en sus nidadas de acuerdo a la competencia local por recursos o a la teoría Fisheriana.

scholarly journals Birth-sex ratios and local resource competition in roe deer, Capreolus capreolus

1996 ◽  
Vol 7 (4) ◽  
pp. 461-464 ◽  
Author(s):  
A. J. Mark Hewison ◽  
J. M. Gaillard
Keyword(s):  
Resource Competition ◽  
Roe Deer ◽  
Sex Ratios ◽  
Capreolus Capreolus ◽  
Local Resource Competition ◽  
Local Resource

Sex Ratio in Primates: A Test of the Local Resource Competition Hypothesis

Oikos ◽  
1989 ◽  
Vol 56 (1) ◽  
pp. 132 ◽  
Author(s):  
Colin A. Chapman ◽  
Lauren J. Chapman ◽  
Karen S. Richardson
Keyword(s):  
Sex Ratio ◽  
Resource Competition ◽  
Local Resource Competition ◽  
Local Resource ◽  
Competition Hypothesis

Sex Ratio and Local Resource Competition

1981 ◽  
Vol 117 (5) ◽  
pp. 796-797 ◽  
Author(s):  
John L. Hoogland
Keyword(s):  
Sex Ratio ◽  
Resource Competition ◽  
Local Resource Competition ◽  
Local Resource
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