Testosterone, Plumage Colouration and Extra-Pair Paternity in Male North-American Barn Swallows
Author Information
Author(s): Eikenaar Cas, Whitham Megan, Komdeur Jan, van der Velde Marco, Moore Ignacio T.
Primary Institution: Virginia Tech
Hypothesis
Males with naturally high elevated testosterone concentrations face a lower risk of being cuckolded and have higher annual reproductive success than males with lower elevated testosterone concentrations.
Conclusion
In North American barn swallows, male testosterone concentration does not play a significant direct role in female mate choice and sexual selection.
Supporting Evidence
- Dark rusty coloured males had higher testosterone concentrations than drab males.
- Extra-pair paternity was common (42% and 31% of young in 2009 and 2010, respectively).
- Tail length did not affect within- or extra-pair fertilization success.
Takeaway
This study looked at how testosterone levels affect male barn swallows' chances of being cuckolded and their overall success in having babies, finding that testosterone doesn't really help them in these areas.
Methodology
The study measured testosterone concentration, plumage color, and fertilization success in male barn swallows over two breeding seasons.
Limitations
The study may have missed some extra-pair gains of males that sired young outside of the study area.
Participant Demographics
The study focused on male North American barn swallows (Hirundo rustica erythrogaster).
Statistical Information
P-Value
0.015
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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