Sentences with word «cowbird»

They played videos of trucks approaching at speeds ranging from 60 to 360 kilometers per hour toward brown - headed cowbirds in an enclosed chamber and studied the birds» behavior.

For some victims of cowbirds, these assaults take a toll.

Social guidance of vocal learning by female cowbirds validating its functional significance.

This name was coined by the great naturalist William Swainson (1789 — 1855) after he observed cowbirds feeding greedily near cattle pens.

The research could help explain why cowbirds lay their eggs in now - accessible forest birds» nests, even though they once were limited to field habitats.

The threatened saffron - cowled blackbird (Xanthopsar flavus) in Argentina has declined in numbers partially because of the shiny cowbird's vicious egg destruction.

That's likely because the victims of screaming cowbird parasitism have wisened up.

Eons ago ancestral male cowbirds probably gathered insects from the backs of the huge bison herds in the Great Plains and carried them back to their mates on the nest.

Despite their stable upbringing, when the young cowbirds grew up they too must have felt the ancient call of the herd.

While the Eurasian cuckoos are threatening to invade North America, American cowbirds are increasing their presence in Eurasia.

So a team of researchers led by Romina Scardamaglia, a behavioral ecologist at the University of Buenos Aires, decided to use new radio - tracking technology to snoop on two kinds of devious cowbirds in Argentina.

What better symbol of our national character than the sleek insouciance of the brown - headed cowbird right on the dollar bill itself?

A few cowbirds actually establish monogamous breeding pairs.

Some North American birds have evolved defenses against cowbirds, which are native brood parasites.

Cowbirds cause more trouble for forest - dwelling species than those in fields.

To see where cowbirds reproduce most successfully, conservation biologist Rachael Winfree of Princeton University in New Jersey compared nests in an old field to those in a patch of forest.

Frank Thompson, a wildlife biologist with the U.S. Forest Service in Columbia, Missouri, says of Winfree's work, «It's important to understand why cowbirds prefer certain habitats to breed in — and this is going to help do that.»

«Honeyguides are the real Jekyll and Hyde of the bird world... like cowbirds or cuckoos, honeyguides are brood parasites — they lay their eggs in other birds» nests and exploit the care of other species to raise their young.

Other researchers have also created functional robotic cowbirds, turkey chicks, and even bees and cockroaches.

Each of the screaming cowbirds later returned to the scene of the crime, too — one even went back to the same nest 39 times after laying.

In the United States, for instance, cowbird populations have exploded thanks to the easy food and nesting opportunities offered by sprawling patchworks of forest and agricultural land.

A new study lays out just how two devious cowbird species plan and execute the perfect crime, and sometimes even return to the scene after the deed is done.

A new study at Western University, however, has shown female brown - headed cowbirds perform spatial...

For this reason, evolutionary pressures have compelled female cowbirds to become more sexually active in order to produce more eggs to leave in more places» as many as forty a year nowadays.

The shiny cowbirds, on the other hand, tended to avoid nests after they parasitized them.

The male cowbird has no parental instincts at all» his life is sex and a casual diet of bugs and seeds.

The bird that best reflects our changed America is the brown - headed cowbird.

But the ancestors of the cowbirds were more committed to their lifestyle.

The scientific name for the cowbird genus is molothrus.

I say it's time to elevate the cowbird to its proper place.

Unfortunately for the cowbird, some bird couples tapped for involuntary surrogate parenthood aren't stupid and will recognize and destroy the cowbird eggs left in their nest or abandon the nest altogether when the foreign deposit appears.

Either way, the cowbird doesn't appear destined for widespread monogamy.

Not surprisingly, cowbirds are more flexible with respect to sexual relationships than are many other bird species.

The story of the cowbird is a resonantly American one.

Someday we may indeed find our parking space as a nation and enter the mall of our destiny, but until then the cowbird best captures where we're headed and why.

Even as each baby cowbird grew to a size and shape entirely unlike the adopted parents, the involuntary surrogate parents never caught on and continued to feed the cowbird as one of their own.

With the coming of European settlers and the massive forest - clearing that followed, the cowbird began to filter into farms, cities, and suburbs where it now thrives in great numbers» at the expense of those species who accept the burden of raising cowbird young.

They were incubated and hatched and the cowbird babies fed by the adoptive parents.

It appears from his notes that Swainson actually meant to use the Greek word molobrus («parasite or greedy person») but he misspelled it and the cowbird has been stuck with «molothrus» ever since.

It is believed that the female cowbird will try to find a nest of the same species that raised her, an example of the well - known biological principle that no good deed goes unpunished.

The abundance of modern U.S. farms and gardens now gives the cowbird an unprecedented opportunity to settle down in fixed territories like other birds.

Many Eurasian birds have evolved defenses against cuckoos, but cowbirds are less picky about choosing their hosts, and might threaten other species that are not parasitized by cuckoos and have no defenses.

Once limited to the Great Plains — a huge field, basically — cowbirds have expanded their range in the past 300 years.

Female cowbirds were better off laying their eggs in forest nests: Cowbirds that laid eggs in fields averaged only five fledglings, she estimated, whereas those that laid eggs in forest birds» nests ended up with 12.7 fledglings.

The brown - headed cowbird is a so - called brood parasite that lays its eggs in other birds» nests, thereby letting other species do all the heavy lifting of chick rearing.

Humans have fragmented forests with fields, giving cowbirds access to habitats they otherwise couldn't penetrate — and apparently hastening the decline of forest songbirds, which can't rear their own chicks as successfully while trying to stuff the gaping maws of cowbird chicks.

The finding could help explain why cowbirds are such a scourge for forest - dwelling songbirds, which run themselves ragged trying to feed baby cowbirds.

«Cowbirds are just doing what they've evolved to do,» Hoover says.

«If the host throws out the cowbird's egg, the cowbird will destroy the nest again and again,» says William Feeney, an evolutionary biologist at the University of Queensland in Brisbane, Australia.

And in the United States, at least two threatened species have been hit hard enough by brown - headed cowbirds (M. ater) to spark cowbird - killing efforts by conservationists.