BASICS


BASICS: This is a blog about my summer life at the Baiting Hollow Hummingbird Sanctuary, at my winter garden, Calypso, in the Bahamas, and aspects of life in general.
The sanctuary is ONLY open certain, very limited, dates/times, starting july 20, and ending sept 15, and ONLY by specific private appointment, at particular, available "slot" times posted at this blog. No visits of any type without a confirmed appointment (paul.adams%stonybrook.edu)

Thursday, November 10, 2016

Hummingbird Hovering

Here's a new video about how hummingbird hover:

http://www.biographic.com/posts/sto/lens-of-time-how-hummingbirds-hover

and for a detailed technical/engineering analysis by the same group see here:

http://lentinklab.stanford.edu/uploads/1428083645_2014%20hummingbird%20wings%20kruyt.pdf

They compare hummingbird hovering with the advanced military Black Hornet micro-helicopter :


The wing shape (width/length ratio) is similar in both hummers and microhelicopters (and much less slender than in regular helicopters. Obviously the wing movements are quite different in the 2 cases: the hummingbird wing flaps and the microhelicopter wing rotates, but this difference is not fundamental: the hummer wing generates lift on both down- and upstrokes by changing the angle of attack (by swiveling the wing) and the rotor instead maintains the same attack angle consistently by continuous swiveling. Nevertheless the paper concludes that the hummingbird is about 27% more efficient than the microhelicopter.

Meanwhile here are more examples (including a Cloudless Sulfur and an American Lady) of the more leisurely flight of butterflies at the sanctuary











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