Flashing wings as a hunting technique

Northern mockingbird IMG_2475©Maria de Bruyn resLast year, during a nature walk, I witnessed young Northern mockingbirds (Mimus polyglottos) displaying odd behavior as they strutted around on the ground. They would walk and hop a bit and then suddenly spread their wings wide and wider still, then close them and continue pecking on the ground.

Some research on the Internet revealed that they were engaged in a phenomenon known as wing flashing. There are various theories about why mockingbirds flash their wings -– to startle insects, ward off predators, attract a mate. So far, there is no scientific consensus on why they do this.

Northern mockingbird IMG_8889©Maria de BruynresNorthern mockingbird IMG_8904©Maria de Bruynres

Having seen both adult and juvenile birds performing this behavior again this year, however, I’ve become convinced it is part of their hunting technique. Those who promote this idea have suggested that the sudden appearance of the bird’s white wing-bars startles insects, but others argue that insects are not alarmed by the color white.

Northern mockingbird IMG_2816©Maria de Bruyn res

Northern mockingbird IMG_2604©Maria de Bruyn res

My own theory is that when the mockingbirds flash their wings, it creates air currents and disturbs the grasses, thereby uncovering and rustling up bugs. This year I clearly saw the birds catching and consuming insects just after a completed wing flash.

snowy egret IMG_3610© Maria de Bruyn

Later in the summer, I witnessed a similar kind of wing flashing used as a hunting technique by an entirely different species, the snowy egret (Egretta thula). These elegant white birds have long black legs ending in feet that look like they are covered with yellow rubber gloves. They stalk the shallows of waterways such as marshes and ponds looking for prey. The bird I saw was fishing in tidal pools along the Atlantic Ocean shore.

snowy egret IMG_3286© Maria de Bruyn

snowy egret IMG_3270© Maria de Bruyn

It is thought that the egrets use their large feet to stir up the sand underwater so that they can more easily see potential food as they forage. Part of the time, they will simply stand like statues, waiting for a fish to swim nearby so that they can suddenly plunge their long beaks into the water to get their meal.

snowy egret IMG_3313©Maria de BruynThis worked at least part of the time for this particular bird, as s/he got a few fish down. It required a lot of patience, however.

snowy egret IMG_3423© Maria de Bruyn res

At a certain point, the bird decided on a more active approach. S/he flew to another tidal pool and then began running to and fro in the water, flapping his/her wings open and closed.

snowy egret IMG_3575© Maria de Bruynsnowy egret IMG_3574© Maria de Bruyn

Occasionally, this was complemented by a leap into the air and plunge into the water – obviously behavior calculated to startle and scare up the fish lurking below the water’s surface.

snowy egret IMG_3606© Maria de Bruynsnowy egret IMG_3617© Maria de Bruyn

snowy egret IMG_3623© Maria de BruynThe tactic worked.

It was fascinating for me to see two such different bird species using their wings in a similar fashion as a hunting method. One of the things I love about wildlife watching -– you can always see and learn something new!

snowy egret IMG_3659© Maria de Bruyn

8 thoughts on “Flashing wings as a hunting technique

  1. Pingback: A tiny bundle of yellow-feathered joy | My beautiful world

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  3. Interesting theory and observation. Could it also be possible that the Mockingbird’s behavior of wing flashing is a instinctual warning to an extinct predator? These birds have been around for a long long time. This would be very difficult to prove, however.

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    • Since writing the blog, I’ve observed mockingbirds engaged in wing flashing more often; it really seems to me that they are doing it to scare up insects since most of the time after they do it, I’ve seen them eating something. The scientists are still debating the purpose of the behavior, however. Thanks for responding to the blog!

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  4. Certainly plausible. I have several returning pairs of Mockingbirds annually. I find them to be extraordinarily interesting creatures. They recognize me and pay no attention. With strangers, cats or squirrels, WW3 begins. I witness these beauties flash their wings while on the ground or perched atop a wall fence. Since there aren’t insects to be had atop the fence, I suppose the wing flashing is reflexive. These ancient birds evolved characteristic behaviors, beak adaptations, coloring and size long before humans emerged. Why did they evolve with large white patches on their wings? It seems to serve no purpose. It is possible that the Mockingbird developed these anomalies against a predator that has gone extinct.

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  5. That’s an interesting idea, John! (Maybe the amount of white on the wings makes them more or less attractive to mates; another idea.) Several birders of my acquaintance dislike the mockingbirds, saying they chase everyone else away from feeders. The mockingbirds at my house don’t do that; they seem content to share the feeders with the other birds.

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  6. Our Mockingbirds are frantic right now. They have fledglings and work together guarding and distracting prey from their nest. They are noisy through the night and I can hear their baby’s piercing whine, which unfortunately attracts the neighborhood cats and squirrels. These pairs return annually because we always have clean water available to them.

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    • How cool that you have birds returning year after year. I’m fairly certain I have catbirds, ruby-throated hummingbirds and a ruby-crowned kinglet returning here each year. Enjoy the birds!

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