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Gouldian Finch Infidelity – Cheating to Acquire Better Genes

Gouldian FinchesRecent studies of the Gouldian Finch (Erythrura gouldiae), an endangered species and popular pet, have revealed that females readily copulate with males other than their mates in order to ensure that the young acquire the best possible genes.

Risky Behavior

Working with finches in captivity and in their natural habitat (Northeastern Australia), researchers at Australia’s Macquarie University found that paired females will indiscriminately cheat on their mates when given the opportunity.  This behavior puzzled he researchers since, if discovered, the females risked abandonment by their mates and would likely be unable to raise their chicks alone.

Choosing the Father

However, further investigation revealed that female Gouldian Finches are somehow able to choose which sperm fertilizes their eggs.  Writing in a recent issue of the journal Science (August, 2010), the researchers established that the sperm of the fittest male, be it the mate or the “extra-marital partner”, fertilized up to 75% of the eggs.  In essence, females cheated with whatever male happened to be available, but were very selective regarding which male actually fathered their brood.

When viewed in this light, female infidelity, while risky, seems an excellent method of insuring healthy offspring.  If the extra male proves less fit than the mate, his sperm would be selected against; if more fit he would father most of the young.

Regardless of which male is fitter, Female Gouldian Finches go to great lengths to hide their infidelity, as they rely upon their mates to provide up to 50% of the care and feeding of the nestlings.

Further Reading

Gouldian Finches are full of surprises – please see my article on Gouldian Finch Care and Breaking Research for more information on these brilliantly-colored birds.

Video showing several spectacular color phases of the Gouldian Finch.


Gouldian Finches image referenced from wikipedia and originally posted by Nigel Jacques (Kris)


  1. avatar

    Hey I just wanted to say that I love your site and find it very useful. I write about bird nutrition often. I was wondering if you had any experience with a foraging toy called Paradise Toys Cagemount Buffet Ball. It looks interesting to me. Do you think it is okay for cockatiels?

  2. avatar

    Hello, Frank Indiviglio here.

    Thanks for your interest in our blog and the kind words; much appreciated. I’m not familiar with the toy you mention, but am very much in favor of foraging toys in general.

    This article on Foraging Toys and Treats mentions some that I have found useful.

    Good luck, enjoy and please keep me posted.

    Best regards, Frank Indiviglio.

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I believe that I was born with an intense interest in animals, as neither I nor any of my family can recall a time when I was not fascinated by creatures large and small. One might imagine this to be an unfortunate set of circumstances for a person born and raised in the Bronx, but, in actuality, quite the opposite was true. Most importantly, my family encouraged both my interest and the extensive menagerie that sprung from it. My mother and grandmother somehow found ways to cope with the skunks, flying squirrels, octopus, caimans and countless other odd creatures that routinely arrived un-announced at our front door. Assisting in hand-feeding hatchling praying mantises and in eradicating hoards of mosquitoes (I once thought I had discovered “fresh-water brine shrimp” and stocked my tanks with thousands of mosquito larvae!) became second nature to them. My mother went on to become a serious naturalist, and has helped thousands learn about wildlife in her 16 years as a volunteer at the Bronx Zoo. My grandfather actively conspired in my zoo-buildings efforts, regularly appearing with chipmunks, boa constrictors, turtles rescued from the Fulton Fish Market and, especially, unusual marine creatures. It was his passion for seahorses that led me to write a book about them years later. Thank you very much, for a complete biography of my experience click here.
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