The bird is actually carrying the feed for baby birds and is really alert before reaching its nest as it may get shot from bird-hunters. So, it was taking longer route to reach its nest and probably, i guess, it was noticing me, and was resting on the tree trunk stump which was right before its nest. And other reason may also be, to confuse the people about where its nest actually is. Its not directly flying to its nest , so that people would not know easily where its nest is.and thus its baby birds can be safe