Hummingbirds and Waterfalls

[Recusant]

High speed cameras were used to look at how hummingbirds and other small flyers get through falling sheets of water. The hummingbirds mostly seem to favor a sideways approach.

"Scientists Film Hummingbirds Flying Through Waterfalls, And It's Beautiful And Genius" | ScienceAlert

Image credit: Victor Ortega-Jimenez

For all the little creatures out there, falling water can be a big hazard. When water drops are a large percentage of your body size, you need clever adaptations to survive even commonly occurring phenomena such as rain. So even greater volumes of falling water, like a waterfall, may as well be a wall to delicate fliers.

But for some insects and small birds, this seemingly impenetrable barrier is surmountable. Several species of birds at least, make use of these natural barriers by tucking their nests safely behind the shimmering walls. Some are known to fly right through this plummeting liquid.

To get a better idea of how this works, researchers filmed hummingbirds passing through falling water. And were surprised at the clever and elegant way they tackle this obstacle.

As we can see below, most of the Anna's hummingbirds (Calypte anna) in the experiment pushed through the water side on - using a leading wing to pierce the wet veil.

"Nothing in the literature could predict that," lead researcher, biologist Victor Ortega-Jimenez from Kennesaw State University, told Science.

[Continues . . .]

The paper is open access:

"Natural barriers: waterfall transit by small flying animals" | Royal Society Open Science

Abstract:

Waterfalls are conspicuous geomorphological features with heterogeneous structure, complex dynamics and multiphase flows. Swifts, dippers and starlings are well-known to nest behind waterfalls, and have been reported to fly through them. For smaller fliers, by contrast, waterfalls seem to represent impenetrable barriers, but associated physical constraints and the kinematic responses of volant animals during transit are unknown. Here, we describe the flight behaviour of hummingbirds (the sister group to the swifts) and of various insect taxa as they fly through an artificial sheet waterfall. We additionally launched plastic balls at different speeds at the waterfall so as to assess the inertial dependence of sheet penetration. Hummingbirds were able to penetrate the waterfall with reductions in both their translational speed, and stroke amplitude. The body tilted more vertically and exhibited greater rotations in roll, pitch and yaw, along with increases in tail spread and pitch. The much smaller plastic balls and some flies moving at speeds greater than 2.3 m s−1 and 1.6 m s−1, respectively, also overcame effects of surface tension and water momentum and passed through the waterfall; objects with lower momentum, by contrast, entered the sheet but then fell along with the moving water. Waterfalls can thus represent impenetrable physical barriers for small and slow animal fliers, and may also serve to exclude both predators and parasites from nests of some avian taxa.

[Randy]

That truly is beautiful.

[Tank]

Gosh!

[xSilverPhinx]

Just this morning I saw a hummingbird flying from flower to flower in the patio. It's been a while since I've seen one.

[Randy]

They're so fast that they are fun to watch.

[Tank]

If I could import a type of creature into the UK I think I would choose humming birds.