Comments for Fairy Wren Passwords

Comment from Paul on 2012-11-14

2012-11-14T13:28:27Z

Sent a link to the story to a birdwatching friend - He wrote,

Fairy wrens are little jewels. Unfortunately, North American warblers and other small passerines have not had evolutionary time to develop such a defense adaptation against the Brown-headed Cowbird, also a brood parasite, since its spread across NA has occurred only since the cutting off of the eastern deciduous forest in the past 200 years.

Comment from Adam on 2012-11-13

2012-11-13T16:07:12Z

Seems like an imperfect solution but evolution is blind so it can't determine which way its going or alter course except through advantages or disadvantages that mutations confer on the offspring.

Perhaps one particular bird started chirping to its egg and the response from the chick made the adult expend more effort to raise it and the trait survived. A bit like how a human is more likely to bond with a baby that gives a big gummy smile over one who doesn't react at all.

And it reached the point that birds who don't get the response tend to abandon their chicks more frequently and in the process abandon cuckoo chicks which means they are more likely to reproduce again and pass and increase the trait.

Comment from Steve Algieri on 2012-11-13

2012-11-13T10:49:54Z

So an imposter chick who did manage to emulate the tones would be performing a 'man-in-the-middle' attack? Nature continues to amaze....

Comment from Chromatix on 2012-11-13

2012-11-13T10:18:47Z

The advantage for the wren, more precisely, is that they can avoid the enormous cost of feeding the impostor chick until it becomes independent. If they no longer hear the password, they can abandon the impostor, and build a new nest and brood.

So it's a mitigation strategy rather than a prevention strategy - a set of airbags and crumple zones instead of power steering and anti-lock brakes.

Comment from Spaceman Spiff on 2012-11-12

2012-11-13T01:19:59Z

I just goes to show, "It doesn't serve to try and fool Mother Nature"! :-)

In any case, perhaps we should sing more to our children when in the womb, so we can better know them, and they, us!

Comment from Canario on 2012-11-12

2012-11-13T00:35:57Z

Maybe the calling repeater is just to check how many chicks are still alive and warm from those "in bad bio-shape" so that heat can be "uniformly distributed" in the incubation process. By re-arranging egg's for instance.

Comment from Dirk Praet on 2012-11-12

2012-11-13T00:30:36Z

Which then of course begs the question: why don't they move on to next logical step, which is kicking out the cuckoo chicks that fail to properly identify themselves ? I guess this deserves a prize for security theatre in the wild.

Comment from Frank Wilhoit on 2012-11-12

2012-11-12T22:11:00Z

Correlate this with the finding a couple of years ago that parrots give their chicks names in the shell. The difference is that parrots do not face this particular problem. Perhaps, in this context, we are imputing a motivation to the behavior based on our preconceptions of why cuckoos so what they do; whereas it may actually be a bird-universal, if anyone took the trouble to check other orders?