This is scientific American 60 second science. I'm Christopher Intagiyata.

Birds in Europe have the same problem as residents of cities like New York in LA,

a housing crisis.

Not enough nest space to go around.

For a species called pied flycatchers

that migrate from West Africa,

things can get deadly if they end up nesting in the wrong spot.

There's no chance for them.

Yelmer Samplonius is a climate change ecologist

at the University of Edinburgh.

He says the flycatchers face fearsome foes

in the form of bigger resident songbirds called Great Tits.

The Great Tits basically splits open a skull at the back and eats the brain.

That's the gist of it.

Samplonius and his colleague Christian Both recorded more than a decades worth of those conflicts in nearly a thousand nestboxes in the Dutch countryside.

They determine that warmer winters can boost resident great-tit numbers, increasing the chance of flycatcher slaughter.

But warmer springtime temperatures can throw the two species nesting times out of sink, which would actually

reduce deadly conflict.

In addition, over the past 30 years, male flycatchers seem to be arriving

earlier and earlier, regardless of springtime temperature trends. In other words,

it's complex. But the upshot is that conflicts between the two birds are on the rise

when some of these shifting factors align and when they do as many as one in

...