Happy Thought for 13 February 2026

Have a Happy Thought:

Humans on bicycles are the most energy efficient animal movement we have yet discovered.

In the chart below, animals (as well as human-created vehicles) are plotted on a graph showing energy cost of transport, per weight. The bottom-right corner is the most efficient – moving the most weight for the least amount of effort.​

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DTAN Studio; Sources: “Energetic Cost of Locomotion in Animals,” by Vance A. Tucker, in Comparative Biochemistry and Physiology, Vol. 34; June 15, 1970 (most data); chart by Dan Todd in “Bicycle Technology,” by S. S. Wilson, in Scientific American, Vol. 228, No. 3; March 1973 (data for human on a bicycle); Tyson Hedrick/University of North Carolina at Chapel Hill (velomobile calculation)

 

So for example a fruit fly and a bee are very light, but not very efficient because it turns out that flying is very “metabolically expensive”.

Things that can swim, like salmon, can be really efficient due to body shape but also because they don’t have to fight gravity (yay buoyancy!)

A human on foot is pretty efficient, all things considered!

But put one of us on a bicycle, and between coasting, using gears to turn muscle power into multiplied forward motion, and the benefits of not fighting gravity all the time:

= near-perfect movement.

(You can look up what a velomobile is on your own time!)

 

This week for #ShareGoodNewsToo:

Scotland’s native flapper skate is on the rebound!

(are you done laughing yet? Grow up!)

(ok I laughed too)

The flapper skate is a type of fish that many of us might call a “ray”.​ (Apparently that would be very wrong though, because while skates lay eggs like most fish, rays give birth to live young!)

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Image: Fenella Wood, University of Aberdeen

Commercial fishing of this and a similar species was banned in Scotland’s waters in 2009. Since then, the number of skates seen both inside and outside of Marine Protected Areas has been increasing. This is according to a recent study that interviewed commercial fishers about how often they see these creatures – most responding “daily”.

Also, if any of you find yourselves in coastal Scotland, you can report any that you see through SkateSpotter.

Thanks to the BBC for bringing us this good news: Flapper skates make a recovery in Scottish waters