Sex-specific differential survival of extra-pair and within-pair offspring in song sparrows, Melospiza melodia
2011

Survival of Extra-Pair and Within-Pair Offspring in Song Sparrows

Sample size: 773 publication 10 minutes Evidence: moderate

Author Information

Author(s): Sardell Rebecca J., Arcese Peter, Keller Lukas F., Reid Jane M.

Primary Institution: University of Aberdeen

Hypothesis

Do extra-pair young (EPY) have better survival than within-pair young (WPY)?

Conclusion

Extra-pair young (EPY) tend to have lower survival rates than within-pair young (WPY), especially among female offspring.

Supporting Evidence

  • Female EPY were about 11% less likely to survive to independence than female WPY.
  • Male EPY had similar or slightly better survival rates compared to male WPY.
  • Recruitment rates were lower for female EPY compared to female WPY.

Takeaway

The study found that baby song sparrows born from extra-pair mating don't survive as well as those born to their parents, especially the girls.

Methodology

The study analyzed 18 years of data on song sparrows, comparing survival rates of maternal half-siblings that were either extra-pair or within-pair offspring.

Potential Biases

Potential bias due to unmeasured environmental or maternal effects.

Limitations

The study may not account for all environmental factors affecting survival.

Participant Demographics

Song sparrows from a small, resident population on Mandarte Island, British Columbia.

Statistical Information

P-Value

p<0.05

Confidence Interval

95% CI

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1098/rspb.2011.0173

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