Flock of birds or something else?

[jaymo]

December 2022, Flagler Beach, Florida.

I was on the beach with two other adult family members, looking east out over the ocean. We observed what initially appeared to be a flock of birds, but quickly noticed they were moving at an unusually high speed. From our perspective, the objects appeared to be roughly a quarter mile offshore and far enough away that we could not make out any defining characteristics typical of birds.

All three of us found the formation, movement, and speed unusual and atypical enough to record a short video before they were too far away as they continued down the coastline. While the most likely explanation may be a group of birds being carried by strong winds or jet-stream conditions, we are interested in hearing additional opinions or alternative explanations.

We are back at the beach now, and seeing a normal flock of birds flying over the water reminded me of this video.

Attached is the raw video file from an iPhone.

 

[Mick West]

It looks identical to other images of birds:

https://www.shutterstock.com/image-photo/flock-birds-flying-line-across-blue-2688022833

 

[John J.]

While the most likely explanation may be a group of birds being carried by strong winds or jet-stream conditions

Looks like a flock of birds. Watch the footage closely on a decent size screen and you can see what are almost certainly wings beating.

As you say, they might be getting a bit of a wind assist, they appear to be moving pretty fast, but I don't think there's anything extraordinary going on. Some bird species are very adept at exploiting air currents.

Unlikely that jet streams are playing a direct role, they're normally a much higher altitude phenomenon:

Jet streams are relatively narrow bands of strong wind in the upper levels of the atmosphere, typically occurring around 30,000 feet (9,100 meters) in elevation.

National Oceanographic and Atmospheric Administration, The Jet Stream https://www.noaa.gov/jetstream/global/jet-stream

The jet stream is a core of strong winds around 5 to 7 miles [8 - 11.3 km] above the Earth's surface, blowing from west to east.

Met Office (UK) https://weather.metoffice.gov.uk/learn-about/weather/types-of-weather/wind/what-is-the-jet-stream

 

[jarlrmai]

This is likely to be a flock of waders, smaller (but still fast flying birds) than the typical geese one is used to see so they are smaller and closer and have more rapid wing patterns, which makes them look faster than one might expect, but they are still fast agile birds and capable of migrating thousands of miles.

 

[Smythe Bacchus]

@jaymo Your observation is an example of a long J-formation of migratory birds. Relevant details below.

Article:

Streefkerk, A.C.P. (2009) On clusters and formations: birds flying in groups. Bachelor's Thesis, Biology.

Flocks of birds perform some aerial phenomena, which have amazed many of its viewers. ... Whereas cluster flying is commonly used throughout the year by groups of birds, for example while transiting between their roosting and their foraging sites, formation flight is almost specifically used for migration... Several specific reasons have been put forward for birds to fly in clusters, mainly regarding predation prevention... Two hypotheses exist for a structured formation, like the well known V-shape. One is the aerodynamic advantage hypothesis,.. The other is the communication and orientation hypothesis,.. These explanations are not mutually exclusive

Source: https://fse.studenttheses.ub.rug.nl/8947/

Article:

Now the bird situated in another bird's upwash has to spend a lot less energy to fly since they are already being pushed upwards by the upwash of the bird in front of it.

Source: https://byjus.com/physics/why-do-birds-fly-in-a-v-format/

Article:

And although the majority of the time you look I the sky and see the birds migrating in a V structure, they also fly in a J like shape as well too. Actually, studies of several species have shown that a J formation is actually more common

Source: https://sites.psu.edu/siowfa15/2015/12/03/why-fly-in-a-v-formation/

Article:

Rotating leaders prevent fatigue

The goose at the front doesn't get any aerodynamic benefit and must work the hardest. That's why geese take turns leading the V-formation. When the lead goose gets tired , it drops back into a trailing position, and another goose takes over.

Navigational accuracy and visual cues

Flying in a V allows each goose to keep an eye on the others and maintain alignment and direction. It also enables younger birds to follow more experienced leaders during long migrations.

Why is one side of the V often longer than the other?

It's believed that the reason for this is due to wind direction. Usually, geese won't fly directly into the wind. So there will be slightly more benefit to the lift generated by the leading bird on one side than the other. The longer tail will usually be on the side providing a greater lift.

Source: https://www.wwt.org.uk/discover-wetlands/blog/why-do-geese-fly-in-v-formation-the-science-behind-the-sky-s-most-iconic-shape

Article:

Scientists calculated how air should flow around a flying bird based on what we know about planes, but almost no one had taken any actual measurements. Henri Weimerskirch changed that in 2001, when he fitted pelicans with heart-rate monitors. He found that birds at the back of the V had slower heart rates than those in the front, and flapped less often.

It was an interesting study, which confirmed that birds benefit from flying in a V. But it didn't address why or how they do so. That's what Steven Portugal wanted to know.

First, he needed the right technology. His colleagues at the Royal Veterinary College, UK developed tiny data-loggers that are light enough to be carried by a flying bird and sensitive enough to record its position, speed and heading, several times a second.

Johannes Fritz had a solution. He works for an Austrian conservation organisation that is trying to save the northern bald ibis—a critically endangered species that makes vultures look handsome. The ibis went extinct in Central Europe in the 17th century, and Fritz is trying to reintroduce it into its old range. His team have reared several youngsters and teach them to fly along their old migration routes by leading the way in a microlight aircraft.

The human/ibis flock stops at fixed places along the route, and a support team follows them on the ground. That gave Portugal plenty of chances to fit the birds with loggers, record every flap of their wings for long stretches, and retrieve the data a few hours later.

"It was always assumed that V-formation flight was learned from the adult birds," says Portugal. "But these guys are all the same age and they learned to fly from a human in a microlight. They learned [V-formation flying] from each other. It's almost self-taught."

(via https://archive.is/GVgWq)

Source: https://www.nationalgeographic.com/science/article/birds-that-fly-in-a-v-formation-use-an-amazing-trick

Discussion of Steven Portugal's study of the bald ibis below.

Article:

The next time you see birds flying in a V formation, consider this: A new study says they choreograph the beating of their wings with exquisite precision to save energy. (Jan 15, 2014)


Source: https://www.youtube.com/watch?v=zkEvEWX9KG8

Source: https://www.youtube.com/watch?v=zkEvEWX9KG8

Longer video of the Steven Portugal study from Nature below.

Article:

In this Nature Video, we see how researchers at the UK's Royal Veterinary College put data loggers on ibises to record their position, speed and wing flaps when they migrated. The ibises position themselves within the V so that they benefit from the flow of air created by the bird in front. They carefully time their wing flaps with their flock mates', to get an extra lift when flying high. (Jan 16, 2014)


Source: https://www.youtube.com/watch?v=fKkzqk3RMLc&t=7s

Source: https://www.youtube.com/watch?v=fKkzqk3RMLc&t=7s

News and letter of Steven Portugal study in Nature Volume 505 Issue 7483, 16 January 2014 is also attached.