Question 314840
Find your favorite bird (one that's not flightless). 
My favorite is the cardinal. 
Average weight is 46 grams. 
In order to determine the wingspan, I need to convert from grams to lbs since the formula works with lbs.
W=46g*(2.2 lb/1000 g)=0.101 lb
Then using the wingspan formula,
{{{L=2.43*W^0.3326=2.43*(0.101)^0.3326=2.43*0.4665=1.13}}}
So from the formula, I would expect the approximate wingspan of a cardinal to be 1.13 feet. Seems high to me but I've never really measured one.
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So pick your favorite (non-flightless) bird, find it's average weight (Internet search), convert to lbs, and crank through the formula.