Good morning,

This is Summer and I will be sitting in for Duke this week.

Today’s story takes us into the tall grass and fence lines of the countryside, where a small brown bird with a big reputation makes its mark — the cowbird.

Now, the cowbird might not look like much — dark plumage on the males, soft brown on the females — but behind those calm eyes is one of nature’s most cunning survival strategies.

Cowbirds are what biologists call brood parasites. That means, instead of building a nest of their own, a female cowbird lays her eggs in other birds’ nests — letting the unsuspecting foster parents do all the hard work.

While the host species — say, a warbler or sparrow — sits patiently on her clutch, one of those eggs doesn’t belong. It’s a cowbird egg. When it hatches, that chick often grows faster and louder than the others, hogging food and attention until the rightful nestlings can’t keep up.

It sounds harsh — and it is — but for the cowbird, it’s been a successful strategy for thousands of years.

So why did cowbirds evolve this way?

It goes back to their origins — they followed bison herds across the Great Plains, feeding on the insects kicked up by hooves. Because those herds were constantly on the move, cowbirds couldn’t stay in one place long enough to raise their young.

So nature found a loophole: lay your eggs in someone else’s nest and let them handle the parenting.

That adaptation allowed the cowbird to thrive — and now, they’re found all over North America, often in agricultural areas or open pastures where livestock still roam.

Adult cowbirds forage in flocks, pecking for seeds and insects. Males are easy to spot — sleek, black bodies with glossy heads — and when they sing, they bow and spread their wings in an odd metallic-sounding song that carries across the fields.

But even young cowbirds have a secret school of their own. Juveniles actually flock together to learn their species-specific songs and social cues, so they grow up recognizing their own kind — even if they were raised by a different species.

And then… there’s the darker side of the story — something researchers call “mafia behavior.”

If a host bird removes a cowbird egg from its nest, the female cowbird may return and retaliate — destroying the host’s remaining eggs or even attacking the hatchlings. It’s brutal, but effective — over time, many host species have learned that it’s safer to raise the cowbird chick than risk losing their own.

Nature, as always, plays tough.