Strategic allocation of ejaculates by male Adélie penguins

@article{Hunter2000StrategicAO,
  title={Strategic allocation of ejaculates by male Ad{\'e}lie penguins},
  author={Fiona M. Hunter and Robert G. Harcourt and Michael Wright and Lloyd S. Davis},
  journal={Proceedings of the Royal Society of London. Series B: Biological Sciences},
  year={2000},
  volume={267},
  pages={1541 - 1545}
}
Sperm competition theory suggests that males should strategically allocate sperm to those females that will bring them the best possible genetic returns. Although males of a number of species of insects and fishes have been shown to allocate sperm strategically, we provide, to our knowledge, the first evidence that an avian species is also capable of allocating ejaculates. Male Adélie penguins (Pygoscelis adeliae) are more likely to transfer sperm during extra–pair copulations (EPCs) than… 

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References

SHOWING 1-10 OF 35 REFERENCES
Ejaculate quality and the success of extra-pair copulations in the zebra finch
TLDR
It is reported that the swimming velocity of sperm of the zebra finch, Taeniopygia guttata, varies predictably within males, and is determined, together with sperm numbers, by the time since last ejaculation.
Ejaculate size varies with socio‐sexual situation in an insect
TLDR
It is concluded that male T.molitor adjust the number of sperm they inseminate according to some perception of the risk of sperm competition, and males subjected to both long‐term and short‐term exposure to potential intrasexual competitors demonstrated the ability to adjust their ejaculate according to socio‐sexual situation.
Ejaculate Cost and Male Choice
TLDR
The problems of limited ejaculatory capacity and male choice merit greater attention in both theory and in empirical research.
Sperm Transfer in the Adélie Penguin
TLDR
This study looks at sperm transfer in a wild population of Ad6lie Penguins by combining behavioral observations of cloacal contact and ejaculate transfer with collection of ejaculates and identification of presence or absence of sperm by microscopic examination.
Risk of sperm competition directly affects ejaculate size in the Mediterranean fruit fly
Sperm competition games: sneaks and extra-pair copulations
  • G. Parker
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1990
TLDR
Ejaculation strategies for cases when an opportunist male ‘steals’ a mating with the female of a paired male are examined, an evolutionary game of competitive ejaculation in which two (or more) males mate with the same female.
Sperm precedence in zebra finches does not require special mechanisms of sperm competition
TLDR
It is shown that empirically measured rates of disappearance of sperm from the reproductive tract, and differences in the number of sperm in the first and subsequent ejaculates of each male, are sufficient to account for observed levels of sperm precedence in zebra finches Taeniopygia guttata.
Mate Switching and Copulation Behaviour in the Adélie Penguin
TLDR
A high frequency of copulation may have evolved in pair males to protect paternity against initial males in this species of penguin, and there is no support for last male sperm precedence from either diurnal or seasonal patterns of copulations relative to fertilisation.
Extra-pair copulation and sperm competition in the zebra finch
TLDR
It is shown that EPCs occurring under semi-natural conditions in captivity result in extra-pair paternity, and sperm from the last male to mate has precedence over previous matings: a single EPC occurring last is disproportionately successful in fertilizing eggs, butEPCs followed by further pair copulations have a low probability of success.
Male crickets increase sperm number in relation to competition and female size
Abstract There is evidence to suggest that males of various species can respond to the threat of sperm competition by varying the amount of sperm transferred during copulation. We tested this in two
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