A 10-hour flight can leave humans longing for solid ground beneath their feet, but for some birds that might not be the case even after months, not hours, on the wing.
The common swift, Apus apus, spends 10 months of the year aloft, according to research published Thursday in the journal Current Biology.
This new study makes the bird a record-setter. Previous research had pointed to the Alpine swift, Tachymarptis melba, as being able to fly non-stop for some 200 days, 100 days less than the common swift. So this new research “extends the range that we know birds can fly,” Niels Rattenborg, a researcher at the Max Planck Institute for Ornithology in Germany who was not involved in the study, tells The Christian Science Monitor.
“Humans didnt learn to fly until a little bit over 100 years ago, for a few seconds,” study lead author Anders Hedenström, a professor of evolutionary ecology at Lund University in Sweden, tells the Monitor. “But evolution has come up with an organism that can spend almost their entire life airborne. I think that is absolutely fantastic.”
“Its not a physical necessity to come down,” Dr. Hedenström says. “I think its more of an emergency thing.” His team noted that a handful of individual birds landed to roost for a few nights during the winter months. But those instances were extremely rare, accounting for less than 1 percent of the non-breeding time, so the researchers chalked these roosting events up to stormy weather or other extreme conditions forcing the swifts to land. Recommended
The birds may prefer an aerial lifestyle because their bodies arent built for efficient movement on the ground. With short legs and clumsy feet, swifts could be easy snacks for terrestrial predators.
But as fliers, the birds are adept and quick, Hedenström says. They can fly at top speeds of about 75 miles an hour, and their body plans allow them to coast on air currents without flapping.
So what are the animals doing up there for months at a time? Everything, Hedenström says.
The birds deftly catch insects in midair to munch on, so they dont need to land to get a snack. They can even mate in the air, adds Hedenström, although they come down to the ground to lay their eggs.
The one puzzle is sleep. All animals need to sleep, he says, so the swifts must have found some way to nod off safely on the wing.
A study of frigatebirds published earlier this year found that they could sleep while airborne. But these sleeping soarers only got about 42 minutes of sleep per day when they were aloft, says Dr. Rattenborg, who conducted the study. Perhaps the same is true for swifts, he says, but how much sleep they need is “really up in the air.”
“We found that the frigatebirds sleep only when theyre gliding, not when theyre flapping,” Rattenborg says. But when it comes to the swifts, “anything is possible. Maybe they can also sleep while theyre flapping their wings,” he says. “We simply do not know.”
Hedenström and his team did observe a curious pattern in the birds flight that might be a clue. Twice a day, at dawn and dusk, the swifts seem to flap a lot more than usual. These high-activity periods are then followed by flight with a lot less flapping. And the birds appear to do this every day.
This pattern is consistent with previous observations of the birds climbing to between one and a quarter miles and two miles in altitude. “We think they climb to high altitude at one time around dawn and one time around dusk,” Hedenström says.
Although the team doesnt know why the birds are doing this, Hedenström suspects it might have something to do with sleep. Perhaps the swifts are climbing high enough to glide down in a long, slow nap. Recommended
“Ornithologists have long speculated about the possibility that common swifts could actually be airborne for their entire non-breeding period of up to 10 months,” Hedenström says. In fact the idea had been formally suggested nearly 50 years ago.
But, Hedenström says, these speculations were merely conjectures based on circumstantial evidence. For example, he says, ornithologists hadnt observed the common swifts roosting in their tropical African wintering “grounds” in any significant number.
So, Rattenborg says, “this is the first study to actually demonstrate that swifts remain flying throughout most of the non-breeding season.”
Hedenström and his team strapped little data loggers to the birds to monitor and record acceleration. These devices sensed when the birds were actively flying.
Common swifts have been known to live to the ripe old age of 20, and with all that flying, Hedenström said, one bird could make it to the moon and back seven times. Youve read of free articles.
About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review under the charming heading of do things that dont interest you:
Many things that end up being meaningful, writes social scientist Joseph Grenny, have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things boring simply because they lie outside the box we are currently in.
If you were to come up with a punchline to a joke about the Monitor, that would probably be it. Were seen as being global, fair, insightful, and perhaps a bit too earnest. Were the bran muffin of journalism.
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A Birds Sex Organs
Your parents did not conduct adequate research if they taught you about “the birds and the bees.”
In contrast to the majority of mammals, 2097% of birds do not have a penis or vagina. Talk about angry birds!.
As an alternative, birds have an internal multipurpose opening called the cloaca, which is also known as the “avian vent.”
Both males and females have the same cloaca, or vent, which functions as genitalia for them.
When the male rubs the female’s cloaca during mating, sperm from its cloaca are released.
The reproductive system of the female is linked to her cloaca, which receives and permits sperm to enter the ova and fertilize the egg.
Therefore, none of them have the normal sex organs that most mammals have. As far as sexual organs are concerned, birds actually resemble fish and reptiles more than mammals.
Scientists are still not clear on why birds genitalia have evolved the way they have, although it is now understood how this happens from a genetics standpoint.
The cloaca is an internal orifice that is present in all female birds and 2097% of male birds.
This multi-purpose organ does a bit of everything. This is where birds lay their eggs, have sex, and expel waste. Yes, the majority of birds only have one “hole” where they use for feces, urination, mating, and even giving birth.
Actually, because they both emerge from the same hole, birds urinate and poop simultaneously rather than at different times.
Additionally, female birds lay their eggs from this same location.
Oddly, only the left ovary and oviductalso referred to as the fallopian tubeare functional in nearly all species of female birds.
Speculation is that having two functional ovaries may create two eggs at the same time and they could possibly collide and break within the oviduct thus harming the female or causing death. But this thus far is speculation and there is no scientific data to explain the reasoning.
How Do Birds Mate?
If youve ever seen birds mate, you know it isnt always romantic. In fact sometimes it looks pretty aggressive.
However, they give what is known as the “Cloacal Kiss” when they mate. The reason for the word “kiss” is that the act itself only takes a few seconds.
Hormonal changes cause each bird’s cloaca to swell and protrude slightly outside of its body when the breeding season reaches a point where it is ready to breed, signaling to the other bird that it is ready to mate.
The female will then let the male perch on her back and move her tail feathers to the side, allowing their cloacals to briefly touch, or “kiss.”
At this point, the male releases the sperm he has stored in his cloaca into the cloaca of the female, where it ascends to the ova (yolk) that develops in the ovary, starting the process of an egg’s development as we know it.
All of this occurs very quicklyusually in a matter of seconds. However, it can also happen more than once before the male bird gets off the female.
Typically, the birds will carry on reproducing for several days or even a week in order to maximize their chances of successful reproduction. During this period, certain birds will also mate with several partners. Both males and females.
Before eggs are fertilized, some female birds may store the sperm for a few days or weeks.
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