Cuckolded Sparrow Fathers Stop Feeding Their Kids

“Predictably Philandering Females Prompt Poor Paternal Provisioning”—that’s the name of a recent report on infidelity in house sparrows. The paper was published in The American Naturalist.

Monogamy means different things to different people—and different animals. House sparrows mate for life, yet years of observation of birds in the wild suggest that they’re also pretty prone to sleeping around. An international team of researchers had a lot of questions about how this works. Are house sparrows really that promiscuous, and, if so, does such behavior pay off? How do the mates of cheating sparrows respond? And how does that affect their kids?

To find out, the researchers set up shop on Lundy Island, an itsy-bitsy spot in the UK’s Bristol Channel. They caught, tagged, and took tiny tissue samples from 200 male birds and 194 females, then released the birds and watched the avian soap opera unfold. Tiny implanted trackers made it possible to tell which bird was which, and when that bird had entered his or her nest.

"Lundy is a unique natural laboratory because it is almost a closed system,” said lead author and Imperial College of London biologist Julia Schroeder in a press statement. “Very few birds leave the island or arrive from the mainland. In the entire 12 years, only four birds immigrated to Lundy, possibly carried by boat."

During that same period, the birds formed 313 pairs and produced 863 broods of baby birds. DNA tests of the birds’ tissue samples, and those of their babies, allowed the researchers to see quite plainly which sparrows were dallying outside their partnerships. A lot of them, it turns out: 38 percent of the broods included offspring from outside partners. Nearly all the couples stayed together once they had bonded, but both male and female birds cheated on their partners.

When those results were matched to video of the sparrows’ behavior, a trend emerged: Cuckolded male sparrows stopped tending to their chicks. This is a big deal for sparrows, a species that depends on care from both parents.

How could the male sparrows tell when their partners had strayed? It wasn’t from looking at the chicks and thinking, “Hey, wait a minute.” The researchers tested this by swapping out a couple’s chicks when they weren’t looking. Dad sparrows couldn’t tell which chicks were theirs, and treated all the little ones interchangeably.

"If chicks were switched into a nest where the female was faithful, then the father at that nest kept up his hard work providing for the chicks, suggesting they have no mechanism, such as smell, to determine which chicks are theirs," Schroeder said.

Instead, the birds are likely relying on context clues. As in: If your mate is going out a lot, and not with you, something might be up. “The males may use cues from the female’s behavior during her fertile period,” Schroeder said, “for example, how long she spends away from the nest.”

Here’s the thing: Animals don’t just sleep around for no reason. Some earlier studies had theorized that cheating might help female sparrows bring fresh genetic material into their nests while maintaining the social stability of a partnership. But if a cuckolded dad starts starving his kids, what’s the benefit?

There may not be one, the researchers say. It’s possible that the sparrows’ cheating hearts are just an evolutionary holdover from the days before the species became monogamous. Or, rather, “monogamous.”

These Sparrows Have Been Singing the Same Songs for 1500 Years

Swamp sparrows are creatures of habit—so much so that they’ve been chirping out the same few tunes for more than 1500 years, Science magazine reports.

These findings, published in the journal Nature Communications, resulted from an analysis of the songs of 615 adult male swamp sparrows found in six different areas of the northeastern U.S. Researchers learned that young swamp sparrows pick up these songs from the adults around them and are able to mimic the notes with astounding accuracy.

Here’s what one of their songs sounds like:

“We were able to show that swamp sparrows very rarely make mistakes when they learn their songs, and they don't just learn songs at random; they pick up commoner songs rather than rarer songs,” Robert Lachlan, a biologist at London’s Queen Mary University and the study’s lead author, tells National Geographic.

Put differently, the birds don’t mimic every song their elders crank out. Instead, they memorize the ones they hear most often, and scientists say this form of “conformist bias” was previously thought to be a uniquely human behavior.

Using acoustic analysis software, researchers broke down each individual note of the sparrows’ songs—160 different syllables in total—and discovered that only 2 percent of sparrows deviated from the norm. They then used a statistical method to determine how the songs would have evolved over time. With recordings from 2009 and the 1970s, they were able to estimate that the oldest swamp sparrow songs date back 1537 years on average.

The swamp sparrow’s dedication to accuracy sets the species apart from other songbirds, according to researchers. “Among songbirds, it is clear that some species of birds learn precisely, such as swamp sparrows, while others rarely learn all parts of a demonstrator’s song precisely,” they write.

According to the Audubon Guide to North American Birds, swamp sparrows are similar to other sparrows, like the Lincoln’s sparrow, song sparrow, and chipping sparrow. They’re frequently found in marshes throughout the Northeast and Midwest, as well as much of Canada. They’re known for their piercing call notes and may respond to birders who make loud squeaking sounds in their habitat.

[h/t Science magazine]

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5 Fascinating Facts About Koko the Gorilla
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After 46 years of learning, making new friends, and challenging ideas about language, Koko the gorilla died in her sleep at her home at the Gorilla Foundation in Woodside, California on June 21, 2018. Koko first gained recognition in the late 1970s for her ability to use sign language, but it was her friendly personality that made her a beloved icon. Here are five facts you should know about the history-making ape.


Francine "Penny" Patterson, then a graduate student at Stanford University, was looking for an animal subject for her inter-species animal communication experiment in the early 1970s when she found a baby gorilla at the San Francisco Zoo. Originally named Hanabiko (Japanese for "fireworks child," a reference to her Fourth of July birthdate), Koko took to signing quickly. Some of the first words Koko learned in "Gorilla Sign Language," Patterson's modified version of American Sign Language, were "food," "drink," and "more." She followed a similar trajectory as a human toddler, learning the bulk of her words between ages 2.5 and 4.5. Eventually Koko would come to know over 1000 signs and understand about 2000 words spoken to her in English. Though she never got a grasp on grammar or syntax, she was able to express complex ideas, like sadness when watching a sad movie and her desire to have a baby.


Not only did Koko use language to communicate—she also used it in a way that was once only thought possible in humans. Her caretakers have reported her signing about objects that weren't in the room, recalling memories, and even commenting on language itself. Her vocabulary was on par with that of a 3-year-old child.


Koko was the most famous great ape who knew sign language, but she wasn't alone. Michael, a male gorilla who lived with Koko at the Gorilla Foundation from 1976 until his death in 2000, learned over 500 signs with help from Koko and Patterson. He was even able to express the memory of his mother being killed by poachers when he was a baby. Other non-human primates have also shown they're capable of learning sign language, like Washoe the chimpanzee and Chantek the orangutan.


Koko received many visitors during her lifetime, including some celebrities. When Robin Williams came to her home in Woodside, California in 2001, the two bonded right away, with Williams tickling the gorilla and Koko trying on his glasses. But perhaps her most famous celebrity encounter came when Mr. Rogers paid her a visit in 1999. She immediately recognized him as the star of one of her favorite shows, Mister Rogers' Neighborhood, and greeted him by helping him take off his shoes like he did at the start of every episode.


Koko was never able to have offspring of her own, but she did adopt several cats. After asking for a kitten, she was allowed to pick one from a litter for her birthday in 1985. She named the gray-and-white cat "All Ball" and handled it gently as if it were her real baby, even trying to nurse it. She had recently received two new kittens for her 44th birthday named Ms. Gray and Ms. Black.


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