Are the calories consumed by birds sufficient to let them fly for kilometres before refuelling ?

Question

Take the example of a pigeon, eating a few grams of seeds. Are the calories sufficient to fuel the bird to fly for kilomtres ?
Could there be another mechanism helping birds to fly ? and the wings only provide steering ?
After all, the birds are decendents of dinosours ?
They have been physically evolving the longest among other species !

Answer 1

That is quite a difficult question to answer as you would have to know how many calories are in a particular food item (which can be determined using a calometry bomb) and how many calories are expended during flight. I would say that no, a pigeon would need more than a few grams of seed to fly kilometers (it also depends on how many kilometers were taking, 2 vs 100 is a huge difference). Many birds migrate overlong distances, but make stops to refuel and take adventage of flight formation (the V of geeese), wind currents, updrafts and anything else they can to make it easier so they really arent technically flying the entire distance, they glide a great majority of it. Although, knowing that they are going to be going a long way, birds do eat and store quite a bit to fuel them.
Wings and the tail provide steering, but its primarily the wings.
So, no a single meal is not enough, but yes the do consume enough calories to fly great distances.

Answer 2

The birds can also let the winds bring them to long distances. albatross do not fly with moves over hundred of kilometers they choose the wind and plane over these huge distances