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Genetic Alteration Keeps Chickens From Caring For Their Eggs

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Commercial chickens do not make good parents. It’s not their fault, though. They’ve been bred to care as little as possible about their offspring. 

Chickens are brood animals, and they have a natural tendency to sit on the eggs they’ve laid to keep them warm. But this tendency, called broodiness, is a problem for farmers who raise chickens for eggs. The more time a hen spends trying to raise the eggs she’s laid, the less time she spends laying new ones. So farmers have bred broodiness out of commercial chickens. 

There's a genetic basis for chickens wanting to take care of their offspring. One particular gene—scientists don’t know exactly which one, but a 2010 study suggests the dopamine receptor D1 (DRD1) gene could play a role—controls whether a hen wants to pluck her own feathers and use them to keep her nest egg warm, or whether she would rather be preening or roosting far from her offspring. When that gene gets bred out of a chicken breed, the hens are more likely to be indifferent to their eggs. 

The mutation likely occurred naturally at first, in White Leghorn chickens, but has since been selected for in other breeds, because bad parenting means good money for chicken farmers.  

[h/t: io9]

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Why Can Parrots Talk and Other Birds Can't?
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If you've ever seen a pirate movie (or had the privilege of listening to this avian-fronted metal band), you're aware that parrots have the gift of human-sounding gab. Their brains—not their beaks—might be behind the birds' ability to produce mock-human voices, the Sci Show's latest video explains below.

While parrots do have articulate tongues, they also appear to be hardwired to mimic other species, and to create new vocalizations. The only other birds that are capable of vocal learning are hummingbirds and songbirds. While examining the brains of these avians, researchers noted that their brains contain clusters of neurons, which they've dubbed song nuclei. Since other birds don't possess song nuclei, they think that these structures probably play a key role in vocal learning.

Parrots might be better at mimicry than hummingbirds and songbirds thanks to a variation in these neurons: a special shell layer that surrounds each one. Birds with larger shell regions appear to be better at imitating other creatures, although it's still unclear why.

Learn more about parrot speech below (after you're done jamming out to Hatebeak).

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Extinct Penguin Species Was the Size of an Adult Human
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A penguin that waddled across the ice 60 million years ago would have dwarfed the king and emperor penguins of today, according to the Associated Press. As indicated by fossils recently uncovered in New Zealand, the extinct species measured 5 feet 10 inches while swimming, surpassing the height of an average adult man.

The discovery, which the authors say is the most complete skeleton of a penguin this size to date, is laid out in a study recently published in Nature Communications. When standing on land, the penguin would have measured 5 feet 3 inches, still a foot taller than today’s largest penguins at their maximum height. Researchers estimated its weight to have been about 223 pounds.

Kumimanu biceae, a name that comes from Maori words for “monster" and "bird” and the name of one researcher's mother, last walked the Earth between 56 million and 60 million years ago. That puts it among the earliest ancient penguins, which began appearing shortly after large aquatic reptiles—along with the dinosaurs—went extinct, leaving room for flightless carnivorous birds to enter the sea.

The prehistoric penguin was a giant, even compared to other penguin species of the age, but it may not have been the biggest penguin to ever live. A few years ago, paleontologists discovered 40-million-year-old fossils they claimed belonged to a penguin that was 6 feet 5 inches long from beak to tail. But that estimate was based on just a couple bones, so its actual size may have varied.

[h/t AP]

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