Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359320
Title: Courtship and male parental care in the Mallorcan Midwife toad Alytes muletensis.
Author: Bush, Sarah Louise.
Awarding Body: University of East Anglia
Current Institution: University of East Anglia
Date of Award: 1993
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Abstract:
Sexual selection theory predicts that the sex with the lower parental investment, usually the male, will be the more competitive and more highly adorned sex. Species in which males have a high investment In the form of parental care or nuptial gifts are instructive for testing the predictions of sexual selection theories. In the Mallorcan Midwife toad (Alytes muletensis), the male performs the parental care by carrying the eggs wrapped in a string around his legs. In laboratory experiments, both sexes were active in courtship and females were observed to compete more frequently than males. Both males and females incurred growth costs as a result of reproduction; males were also susceptible to physical injuries including the loss of limbs during brooding. Because the costs of reproduction are high for both sexes, either sex might be expected to exercise choice when finding a mate. Large males were not significantly better at caring for the eggs than were small males, and there was no correlation between female size and clutch size. Both sexes could benefit by choosing large mates, however, because hatchling size was significantly associated with both male size and female size, and large hatchlings are likely to enjoy fitness benefits. No evidence for female mate choice was evident in two-speaker arena experiments, but it is possible that mate choice in this species is mediated by non-acoustic cues. Double clutching, which enables brooding males to reduce the mating cost of providing parental care, is less common in A. muletensis than in the other species of midwife toads. Experiments and models indicated that the low frequency of double clutching is probably due to a time limit which constrains males to obtaining the second clutch within three days of the first. The potential reproductive rate of females was higher than that of males, suggesting that a female-biased OSR is responsible for the observed competition between females, but the reproductive rates of both sexes are expected to vary with the seasons. The resulting shifts in the OSR should be accompanied by seasonal shifts in the competitive sex
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.359320  DOI: Not available
Keywords: Zoology Zoology
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