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Researchers find narrow window in songbird migration



Migratory songbirds usually fly under the cover of darkness, but the reason for their flight has long eluded researchers. Now, a couple of studies show that birds rely on the onset of twilight and the assumption of clear skies ahead as cues for flight.

The study, published in the journal Movement Ecology, used radio tracking devices and analyzed data from nearly 400 songbirds belonging to nine migratory species, including the yellow-rumped warbler, American redstart and Bicknell’s thrush.

Like most other migratory birds, these species migrate at night, probably to avoid predators, keep cool, and use the daylight hours for feeding. However, the exact reasons why they start their flights when they do so have long been a matter of debate, with some scientists suggesting that they time their sorties to maximize night flight time, or that they rely on celestial objects. such as visible stars, for flight reference.

To try to better understand the timing of birds, the researchers decided to conduct their research where migration begins rather than at stopping points along the way. This allowed them to reduce the impact of variables, such as fuel availability, that could influence the birds’ flight decisions.

The radio data showed a much narrower migration take-off window than expected. ninety percent of the birds identified by the researchers as capable of seasonal migration did so within 69 minutes of dusk.

“It’s a very narrow window, which suggests there’s something important going on at this time of night,” said Nathan Cooper, a research ecologist at the Smithsonian National Zoo and Institute for Conservation Biology and the paper’s first author. news release. “And we argue that this constant early-night departure time is related to the maximum increase in night flight time.”

Second analysis disclosed that migratory songbirds are good meteorologists. When the researchers took a closer look at the four species, they found that the likelihood of departure was “associated with changes in barometric pressure, almost entirely independent of species, season, or location.” They are likely to depart when the barometric pressure has risen in the previous 24 hours, indicating good weather in the coming days.

However, the weather is likely just one of many factors driving the birds to migrate, the researchers say, citing other sources. research this suggests that the timing of migration also depends on sex, age, and celestial signals.

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In coastal Bangladesh, climate change undermines women’s reproductive health



Research published last year by IpasA US-based reproductive justice NGO has found that global warming has exacerbated existing gender inequalities and directly or indirectly affected women’s sexual health, pregnancy outcomes, contraceptive use and fertility intentions in Bangladesh and Mozambique, two climate-sensitive countries.

The report says that during extreme weather events exacerbated by climate change, such as cyclones, access to medical care and contraceptives was limited. The researchers also found that the climate crisis has exacerbated economic instability and added an additional burden to women’s caregiving responsibilities.

In some cases, this could mean women taking on dangerous jobs to provide for their families, says Sally Deikerman, a senior researcher at Ipas who worked on the report.

“You, as a woman, may be forced to roam waist-deep in water where you catch fry to feed your family, and these rivers are not only polluted by cyclones and the destruction of sewer systems, but sea levels are rising, leading to more and more salinization of the water,” she said. “It directly affects their reproductive organs, causing infections, cancer and injury.”

In Sathira, salt water intrusion has cut off access to clean drinking water, Akhter said.

“There is not a drop of fresh water in the whole area,” she said. “It will take two hours to get fresh water.”

Fatima Idris Eva, a health worker in the Shyamnagar city of Sathira, said she had noticed an increase in the number of patients, including men, with sexual or reproductive ailments over the past two years. According to Eva, this includes women reporting irregular periods, discharge, and sores around the uterus.

“The water in different parts of Shyamnagar is extremely salty,” she said in Bengali. “We have a lot of patients coming in who have uterine problems due to drinking salt water. It’s worrisome.”

But the burden on some women may come long before climate-related health problems arise. Poor families may force their daughters to drop out of school to work or decide to marry off their girls at an early age to alleviate financial stress. Akhter said she herself stopped going to school and got married after Cyclone Ayla that hit Bangladesh in 2009 left her parents in a financial crisis.

“This salt water ruined my childhood, school and life,” she said.

Similarly, twelve-year-old Sakila Akhtar had her childhood years stolen to help her family out of poverty. She said that she once dreamed of becoming a politician in order to change the fate of people in her hometown, but now she is the mother of a one and a half year old daughter.

“I wanted to discover the world in different ways and be able to do many things, like crafts, but now I have to work as a day laborer with a child in my arms,” Akhtar said in an interview in Bengali. “My father has nothing. I had to settle down and get married. My husband is also poor.

Sakila Akhtar said she once dreamed of becoming a politician to change the fate of the people in her hometown, but now she is the mother of a one and a half year old daughter.Fabeha Monir for NBC News

Akhtar said she has irregular periods and heavy discharge and her doctor recommended fresh water bathing, but there is none nearby.

Jahanara Begum, 65, remembers when it wasn’t always like this.

“Once there was fresh water here,” she said in Bengali, adding that she now has to travel more than 4 miles to bring drinking water.

Even during the rainy season, households cannot store enough rainwater to last for a long time.

Begum said her husband was ill and she was suffering from uterine cancer and diabetes. Prolonged exposure to brackish water also caused her to itch all over her body.

“I visit doctors and take medication, but there is no solution,” she said. “So many diseases have settled in my body in these few years.”

Women’s reproductive health risks are expected to rise as cyclones and floods become more frequent and intense due to global warming, and as sea levels continue to rise. Studies show that global average sea levels have risen more than 8 inches since 1880, and scientists predict that by 2050 roughly 17% of Bangladesh could be flooded.

“Here everything turns into a cyclone,” said 12-year-old Akhtar. “Here, thinking about the future of people, the storm breaks houses, breaking people’s lives. Here everyone is happy, but everyone is sick.”

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Poem: “Confluence” – Scientific American



Science in meter and verse

This article was originally published as Confluence in Scientific American 328, 5, 24 (May 2023).

doi: 10.1038 / scientific American 0523-24


Marianna Karplus, a geophysicist and associate professor at the University of Texas at El Paso, was inspired to write poetry during her scientific field trips to the US west, the Himalayas and Antarctica. Her poems have been published in several literary magazines.

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NASA, Rocket Lab Update Tropical Cyclones Mission Launch Information



After the previous target launch date was changed due to weather conditions in New Zealand, NASA and Rocket Lab are now targeting 9:00 pm ET on Sunday, May 7 (1:00 pm on Monday, May 8, EST New Zealand) to launch two CubeSats to track storms. into orbit

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