The Reason So Many Babies Are Conceived in Winter

yurizhuravov/iStock via Getty Images
yurizhuravov/iStock via Getty Images

Does it feel like many friends and family members announce the pending arrival of a baby during the fall and winter months? That’s not exactly a coincidence. It turns out the cold season is associated with more reproductive activity than any other time of the year. The month of December alone accounts for 9 percent of conceptions in the United States. Science is gaining a better understanding of why.

All living creatures heed an evolutionary instinct to target seasonal births. If conception happens during colder months, babies will be born during warmer months, when resources will be bountiful. Northern states have births peaking in June and July, while southern states come a bit later in October and November. The farther south, the later the birth peak, since people in these warm climates are less influenced by frigid temperatures.

What are frisky humans responding to in colder months? Research suggests that the cooler temperatures and shortened days signal that it's time to get busy. Other theories suggest that men may be more fertile in colder months, or that a woman’s ovum receptivity might change with decreased daylight. Not only are couples potentially more sexually active, but that activity might wind up being more (re)productive.

Are there benefits to conceiving at other times? Possibly. One 2013 study published in the Proceedings of the National Academy of Sciences gathered data from nearly 1.5 million births and found that average birth weight in the first five months of the year decreased by 10 grams. Babies born during the summer months were 20 grams heavier. Mothers who conceived in summer tended to gain more weight than those who conceived at other times.

If you have a disproportionate amount of friends with a September birthday, it’s likely that their parents consciously or unconsciously followed their evolutionary instinct nine months earlier.

[h/t Smithsonian]

Whiten Your Teeth From Home for $40 With This Motorized Toothbrush

AquaSonic
AquaSonic

Since many people aren't exactly rushing to see their dentist during the COVID-19 pandemic, it's become more important than ever to find the best at-home products to maintain your oral hygiene. And if you're looking for a high-quality motorized toothbrush, you can take advantage of this deal on the AquaSonic Black Series model, which is currently on sale for 71 percent off.

This smart toothbrush can actually tell you how long to keep the brush in one place to get the most thorough cleaning—and that’s just one of the ways it can remove more plaque than an average toothbrush. The brush also features multiple modes that can whiten teeth, adjust for sensitive teeth, and massage your gums for better blood flow.

As you’d expect from any smart device, modern technology doesn’t stop at functionality. The design of the AquaSonic Black Series is sleek enough to seamlessly fit in with a modern aesthetic, and the charging base is cordless so it’s easy to bring on the go. The current deal even includes a travel case and eight Dupont replacement heads.

Right now, you can find the AquaSonic Black Series toothbrush on sale for just $40.

Price subject to change.

 

AquaSonic Black Series Toothbrush & Travel Case With 8 Dupont Brush Heads - $39.99

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7 Facts About the Hurricane Highway

Hurricane Earl (top) and Hurricane Fiona (bottom) pummel the U.S. coast and Caribbean islands.
Hurricane Earl (top) and Hurricane Fiona (bottom) pummel the U.S. coast and Caribbean islands.
NOAA/NASA GOES Project // Public Domain

Autumn is the peak of hurricane season, also known as Cape Verde season, after the islands where the so-called "hurricane highway" originates. Here are seven facts about this awesome—and sometimes deadly—weather phenomenon.

1. The hurricane highway begins near the African coast.

The Cape Verde Islands, located off the northwest coast of Africa, are where the hurricane highway starts. Thunderstorms destined to become hurricanes often form into a tropical depression near the islands, slowly organizing and strengthening over the following week as the system moves toward the Caribbean. These storms have a long time to get their act together, but they also have to cover a lot of distance without losing their power to reach the East Coast as a hurricane. Some storms are able to thrive with little wind shear, ample warm water, and moist air, while others starve and dissipate if they encounter cooler waters and strong winds, or ingest dry, dusty air blowing off the Sahara Desert.

2. An easterly jet stream gives rise to the hurricane highway.

It’s hard to imagine from North America that a couple of thunderstorms on another continent thousands of miles away can swirl up into a monstrous storm, but it happens almost every year. The extreme temperature gradient between the blistering heat of the Sahara Desert and the more temperate climate of the savanna to its south creates an easterly jet stream that triggers clusters of showers and thunderstorms. These clouds then move from east to west, emerging off the western African coast near the Cape Verde Islands. Every year, the right conditions turn a handful of these localized storms into tropical storms that make their way across the Atlantic.

3. The biggest hurricanes start with the smallest storms on the hurricane highway.

Infrared image of Hurricane Andrew
Hurricane Andrew was a Category 5 hurricane when it made landfall in Homestead, Florida.
Xanxz/NOAA, Wikimedia Commons // Public Domain

Hurricanes, cyclones, typhoons—these are all names for the same force of nature, like Hurricane Andrew, which hit the East Coast in 1992. Cyclones like Andrew don’t just form out of thin air. All tropical cyclones require a relatively tiny “nucleus” of thunderstorms in order to develop. When the air and water temperatures are right, these groups of thunderstorms sometimes spin up into a fierce low-pressure system capable of causing a lot of damage. We see lots of these seedling thunderstorms over the ocean every year, but only a small number of them become hurricanes.

4. Hurricanes form in different places in different months.

Where a tropical storm or hurricane begins its trip across the ocean depends on what time of the year it forms. Storms that form early in the season usually get their start from thunderstorms or cold fronts that stall over the water very close to land; almost all of the storms that form in the Atlantic in June come to life within a few hundred miles of land. When we reach the peak of hurricane season, though, they start to form farther and farther out in the ocean—all the way out to the shores of Africa.

5. Fall is the peak of hurricane season on the hurricane highway.

Hurricane season in the Atlantic Ocean runs from June 1 through November 30. Storms are most common during that six-month stretch of the year, but sometimes they can form earlier or later too. That said, the period between the middle of August and the middle of October is typically the climatological peak of the season. That’s because, as the ocean water gets warmer, the atmosphere becomes conducive to vigorous storms, increasing the risk for hurricanes and tropical storms.

6. Cape Verde hurricanes can easily land in the record books.

Hurricane tracks over time

Tropical waves traveling west from the coast of Africa in the middle of the summer are the culprits behind some of the worst hurricanes we’ve experienced in the United States. For example, on August 8, 2005, a small tropical wave emerged off the coast of Africa, soon becoming Tropical Depression 10. That depression would fall apart a few days later, but its remnants kept moving toward the U.S., redeveloping into a new tropical depression over the Bahamas on August 23. That new tropical depression became Hurricane Katrina, the costliest hurricane to ever strike the United States.

It’s a similar story for many—but not all—major hurricanes in recent history. Hurricanes Andrew, Dennis, Ivan, Isabel, and Ike were all Cape Verde–type storms that sprang to life thousands of miles away from where they would ultimately wreak havoc.

7. Strong hurricanes can still form in other places in autumn.

While the far eastern part of the Atlantic Ocean is a hotbed of activity this time of the year, it’s not the only place you need to watch if you live near the coast. Storms that form close to land can quickly spin themselves into catastrophe. Hurricane Sandy formed just south of Jamaica and hit New Jersey in a matter of days in 2012. A tropical depression that developed east of Florida on September 18, 2005, exploded into Hurricane Rita just three days later, with 180 mph winds—the most intense storm ever recorded in the Gulf of Mexico.

Meteorologists are currently predicting an above-average hurricane season in 2020. It may be worth preparing: NOAA suggests gathering a few key disaster supplies to have on hand, getting an insurance check-up, and locating the safest high ground.