How temptations of having a better mate outside their ‘bond’ pushes the Gouldian finches (Erythrura gouldiae) to cheat on their mate not just once or twice, maybe even multiple times.

Figure 1: Photo showing a male (red) and female (black) Gouldian finch. 

Source: Australian Geographic, 2010 (Photo: Sarah R Pryke)

The promiscuity of the female finches often rewards them with better and stronger offspring (Pryke et al, 2010). However, every ‘investment’ has its risks. These females tread on thin line between having the best of both worlds (having healthy offspring and a male to raise them) or none, as males would either leave them or in rarer case, put in less effort in raising the offspring (Cooper, 2010). Therefore, they would try all means to hide their infidelity from their partner in fear of enduring the hardship of a ‘single mother’.

Research has shown that the females have the ability to differentiate between higher quality sperms from lower ones and if the ‘new lover’s’ genes are compatible with theirs (Pickrell, 2010). This prompts them to engage in extra-pair copulations (aka adulteries) in search for the most ideal sperms with genes that are compatible with theirs or even of higher genetic quality then their current partner’s (Pryke et al, 2010). Such behaviour is said to be for the better good as it not only ensures that their offspring are healthier, more importantly, it ensures that better genes are passed down to generations through natural selection (Jennions & Petrie, 2000).

Moreover, if females breed with the wrong partner of incompatible or poorer quality genes, more than 60% of the time, their offspring is likely to die and this may threaten their survival (Pryke et al, 2010).

So what can we say of these female Gouldian finches behaviour? Morality aside, I would say that their ‘cheating’ behaviour makes them who they are- attractive and stunning birds with quality genes that ensure its beauty endures and stand the test of time.

Hence, CHEATING JUSTIFIED!

Click here to see what Dr Sarah Pryke has to say about these colourful birds and their behaviour during her interview with Mark Horstman on ABC TV!

References

Cooper, D., 2010. Cheating reaps big benefits for Gouldian Finches. ABC Science, 20 August 2010. URL: http://www.abc.net.au/science/articles/2010/08/20/2987882.htm (accessed on 8 April 2013).

Jennions, M. D & Petrie, M., 2000. Why do females mate multiply? A review of the genetic benefits. Biological Reviews of the Cambridge Philosophical Society, 75(1): 21-64

Pickrell, J., 2010. Promiscuity pays for female finches. Australian Geographic, 20 August 2010. URL: http://www.australiangeographic.com.au/journal/promiscuity-pays-for-female-finches.htm (accessed on 8 April 2013).

Pryke, S. R, Rollins, L. A & Griffith, S. C., 2010. Females use multiple mating and genetically loaded sperm competition to target compatible genes. Science, 329(5994): 964-967.