How Your Kids Could Be Stopping You from Being the Coolest Version of Yourself

We all like to think that in a moment of danger, we would immediately recall every summer karate class or that cool action sequence in the last Marvel movie and save the day with a few roundhouse kicks and maybe a backflip or two. But what if your kids were suddenly involved? Would you still channel the power of Liam Neeson and become even more aggressive? Or play it safe and just try not to have either you or your children seen? A study from Australia attempted to answer this question for the superb fairy-wren (Malurus cyaneus) as they observed this species’ response to various different threats when they were only in pairs and when they had nestlings.  Would these delicate birds stay quiet and attempt to hide? Or would they call attention to the threat and themselves in the hopes to recruit the aid of other birds?

The study done by Diane Colombelli-Negrel from Adelaide, Australia studies the vigilance and response calls of superb Fairy wrens (Malurus cyaneus) in reaction to various predators including snake, fox, and currawong models. The amount of time spent observing the threat, or the vigilance, the number of alarm calls emitted by the wrens when the threat was present, and the number of birds recruited to the alarm calls were measured. It was predicted that wrens would distinguish between the threat posed by different predator models and act accordingly. Researchers also believed that the wren pairs with nestlings would respond differently to threats that pairs without nestlings. While the snake poses the least danger to an adult wren, they pose the largest threat to nestlings as opposed to the other predators tested in this experiment. Currawongs however pose the highest threat to adult wrens due to their ability to move speedily both upwards and horizontally. Due to these differences in threat levels, it was predicted that wrens would vocalize to the biggest threat to their situation (either with nestlings or without nestlings). They also hypothesized that both pairs with and without nestlings would be comparably vigilant regardless of the threat.

Researchers introduced stuffed models of the predators while the birds were on the nest to simulate a threat for five minutes. A researcher hidden under brush close by observed the reactions of the wrens by measuring the number of vocalizations and the amount of time the birds spent scanning and observing the predator. The researchers also tracked the number of birds attracted by the vocalizations emitted during the testing period. They found that as they had predicted, the vigilance pattern between pairs with nestlings and pairs without nestlings were comparable, showing a “shared perceived risk of predation dependent on predator type”. The researchers also found that the pairs with nestlings vocalized more when threatened with the snake as compared to any other predator, while the pairs without nestlings vocalized more when threatened with the fox and currawong models. It was also discovered that the number of birds attracted to the alarm calls was not dependent on the threat type. The same number of birds on average were attracted to alarm calls regardless of the presence of nestlings or the type of predator.

This study has very interesting implications on the cognition of the superb fairy-wren. Not only are the birds capable of discriminating between various threats, but they also take into account the effect of vocalizations on their nestlings. The lack of vocalizations towards foxes and currawongs in pairs with nestlings is likely due to the simple fact that making more noise attracts even more predators. If the predator did not immediately pose a threat to the nestlings, the wrens were much less likely to vocalize opposed to pairs without nestlings. This study also emphasizes the significant effect nestlings have on the behavior of the adult pair, therefore it is an important factor to consider when studying other aspects of behavior within this species. So the next time you imagine a scenario where you could save the day from evil, just consider the effect a helpless child by your side may have on your ability to knock out your enemy with a swift kick. Maybe it would just be best to call on someone else for help.

References

Colombelli-Négrel, D., Robertson, J., & Kleindorfer, S. (2010). Nestling presence affects the
anti-predator response of adult superb fairy-wrens (Malurus cyaneus). Acta Ethologica,
13(2), 69-74. https://doi.org/10.1007/s10211-010-0072-7