There are three tables, each assuming different atmospheric densities because Lift scales linearly with atmospheric density over the range here.
Then for each table we look at a baseline Harpy eagle and a baseline Philippine eagle (aka Monkey eagle) and scale and modify from there.
On the table columns:
Scale Factor: Size increase in every dimension from the base creature.
Wingspan: Wingspan in meters, using value for largest normal member of species.
Lift: Combines the weight of the largest normal member of the species with the largest prey it has been observed to grab and fly away with.
Weight: Weight of the largest normal member of the species.
Load: Lift minus Weight, so this is what your mount can lift off the ground, carry and still fly.
Modifications to the base animal simply assume a greater strength to weight ratio. In some very cursory internet research there is a wide variation in this between birds. Not surprising as there are many other things that are more important than this depending on a bird's niche and place in the predator prey web.
Thus a mod of x1.25 means that pound per pound the bird is 25% stronger than baseline, so keeping the form factor and lift constant that means the stronger bird is 1/1.25 times lighter. There are three postulated extra-strong versions from baseline Bird Plus (x1.25 strength/weight); Super Bird (x1.5 strength/weight), and Mega Bird (x2 strength/weight).
Then for each table we look at a baseline Harpy eagle and a baseline Philippine eagle (aka Monkey eagle) and scale and modify from there.
On the table columns:
Scale Factor: Size increase in every dimension from the base creature.
Wingspan: Wingspan in meters, using value for largest normal member of species.
Lift: Combines the weight of the largest normal member of the species with the largest prey it has been observed to grab and fly away with.
Weight: Weight of the largest normal member of the species.
Load: Lift minus Weight, so this is what your mount can lift off the ground, carry and still fly.
Modifications to the base animal simply assume a greater strength to weight ratio. In some very cursory internet research there is a wide variation in this between birds. Not surprising as there are many other things that are more important than this depending on a bird's niche and place in the predator prey web.
Thus a mod of x1.25 means that pound per pound the bird is 25% stronger than baseline, so keeping the form factor and lift constant that means the stronger bird is 1/1.25 times lighter. There are three postulated extra-strong versions from baseline Bird Plus (x1.25 strength/weight); Super Bird (x1.5 strength/weight), and Mega Bird (x2 strength/weight).