Lunar cycles at mating do not influence sex ratio at birth in horses

Aguilar, Javier; Cuervo‐Arango, J.; Juliana, L. Santa

doi:10.3109/07420528.2014.950738

Cited by 6 publications

(3 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the significance of the effects of the moon phase and weather conditions on physiology is a subject that arouses controversy within the scientific community, given the disparity of the results found. Several studies that have been carried out with regard to this applied field have concluded the effects were not statistically significant or the modeled size of the effect was not consistent enough so as for a clinical implication to be determined [ 26 , 27 ].…”

Section: Introductionmentioning

confidence: 99%

Lunar Cycle, Climate, and Onset of Parturition in Domestic Dromedary Camels: Implications of Species-Specific Metabolic Economy and Social Ecology

Pastrana

González

Bermejo

et al. 2023

Biology

View full text Add to dashboard Cite

Given energy costs for gestating and caring for male offspring are higher than those of female newborns, external environmental conditions might be regarded as likely to affect the timing of delivery processes differentially depending on the sex of the newborn calf to be delivered. The aim of the present paper is to evaluate the association between environmental stressors such as the moon phase and weather-related factors and the onset of labor in female dromedaries. A binary logistic regression model was developed to find the most parsimonious set of variables that are most effective in predicting the probability for a gravid female dromedary to give birth to a male or a female calf, assuming that higher gestational costs and longer labor times are ascribed to the production of a male offspring. Although the differences in the quantitative distribution of spontaneous onset of labor across lunar phases and the mean climate per onset event along the whole study period were deemed nonsignificant (p > 0.05), a non-negligible prediction effect of a new moon, mean wind speed and maximum wind gust was present. At slightly brighter nights and lower mean wind speeds, a calf is more likely to be male. This microevolutionary response to the external environment may have been driven by physiological and behavioral adaptation of metabolic economy and social ecology to give birth to cooperative groups with the best possible reduction of thermoregulatory demands. Model performance indexes then highlighted the heterothermic character of camels to greatly minimize the impact of the external environment. The overall results will also enrich the general knowledge of the interplay between homeostasis and arid and semi-arid environments.

show abstract

Section: Introductionmentioning

confidence: 99%

Lunar Cycle, Climate, and Onset of Parturition in Domestic Dromedary Camels: Implications of Species-Specific Metabolic Economy and Social Ecology

Pastrana

González

Bermejo

et al. 2023

Biology

View full text Add to dashboard Cite

show abstract

“…in the absence of birth limitation methods). 6 One study showed that the sex ratio was not statistically related to different lunar phases or days, 5 although others favor the strong evidence that the offspring sex ratio varies with the time of conception within the cycle. 6 The third question regards whether higher coitus rates inadvertently skew the M/F ratio in favor of an excess of males.…”

mentioning

confidence: 98%

“…5 In fact, there is a large body of research on the variation of human sex ratios based on: (1) the time of insemination within the mother's fertile cycle; (2) the duration of gestation; (3) coital frequency, here called the "coital rate"; and (4) the amount of time taken to achieve conception within a period of risk (viz. in the absence of birth limitation methods).…”

mentioning

confidence: 99%