Where Does The Nest-Building Instinct Come From?

[Leo]

So many of us know now that a lot of things we used to believe were instinct are actually information transfer: bird songs, bird migrations, dam building in beavers, and so forth.

However, here's a question that stumps me, and if a Christian asks it I'd love to have an answer:

Nest-building. How is the information transferred from parent to offspring for nest construction?

Baby birds learn a few things from their parents: flight, foraging, danger avoidance, grooming, etc. Even the songs are passed on from father to son in many species. In quite a few migratory birds, the offspring migrate with the flock the parents are members of for the first year. Many, not all. Others migrate with a flock, regardless of parents being in it, but it's clear they learn the way the first time around.

All these things at one time were thought to be instinct. Now we know this is all parent-offspring transfer of information. Nest-building is another matter. Birds build and repair nests before the eggs are laid, and when the offspring leave the nest, they don't return to it. In other words, they never observe their parents building nests.

 

One could argue there's a transfer of information via language that we haven't cracked yet. Bird songs and calls are infinitely more complex than we ever used to think. Take your favorite birdsong and some audio editing software, slow the song down to a quarter speed and note all the tonal and linguistic variations. Not just the songs but the "chatter" within a flock context. That doesn't, of course, indicate language transfer of this sort. But many are conversational animals and use their chatter to indicate location, food sources, and so forth.

 

Anyhow, I'm not sure how instinct as we understand it for something as complex as building a nest can be encoded in the DNA. Does anyone have a good resource on this? It does seem a lot more things in vertebrates come down to information transfer. Certainly in birds this has been the case. But there's a gap here, because offspring never observe their parents building a nest.

I guess information transfer is easier to conceive of than instinct for something as structurally complex as a bird's nest. It's not like and anthill or a beehive built in modules. You either get it right or you get disaster.

 

Anyway, just curious what you all think. I know as a Christian who accepted the theory of evolution by natural selection, I dreaded some Young Earther addressing me with this question. And they often presented cases to "prove" a young earth situation which I could take apart. Fortunately, none I knew were that educated on ornithology or thought to toss this one at me. It's a logical question -- how does this get transferred.

And yes, there's plenty of bird nests of all shapes, sizes and locations, including burrows that resemble something a reptile would use. I think the graduation of nest-building technology is not difficult to explain. But parent-to-offspring transfer seems to be. I've never read anything that discusses where in the DNA so-called instincts like this get stored. This just looks like something that should be the result of an information transfer of some form.

 

Anyway, grateful for any responses.

[florduh]

richarddawkins.net had an article a couple of years ago that addresses the subject.

 

A new study has found birds learn the art of nest-building, rather than it being just an instinctive skill.

 

 

http://old.richarddawkins.net/articles/643243-new-study-says-birds-learn-how-to-build-nests

[Leo]

Ah thank you. My motives were not entirely counter apologetic in nature: birding is one of my favorite things -- I'm such a dork about it I spent over $30 for a really sexed up bird field guide app for my phone. And me being a blind guy, I've never owned a field guide before. They never used to put that sort of thing into Braille for us. Now with the Internet there's no "they" and no "us" ... again thanks and will devour that article.

BTW reading some of Dawkins' lesser-known works these days.

[Leo]

Interesting article. They don't address how they first learn about nest building though.

In order for birds to learn to fly, for instance, they observe others in flight, and start with practice hops -- that "cute" hopping across the ground baby birds are known for. That's just pre-flight practice, they don't know how to take off properly.

Most species -- apparently not the weaver birds -- never see their parents building the nest. The nest gets built, young reared, and then they separate. Smaller sparrows, and apparently weavers from this article, raise multiple broods per year, and the offspring learn by caring for the new batch, kind of like a birdie Walmart Special or 19 and Counting.

Anyway this is at least interesting, and a start.

Thanks for passing it on.