With our lapwings they will bomb dive very close driving you off.
Tenacious birds sadly the fate in your case was flooding and cattle, down here we have the monkeys raid the nests, snakes, monitor lizards so birds do have a rough time raising their young.
Nice you found the eggs and kept a watchful eye on what was going on.
!BEER
RE: Lapwings in a Flooded Field of Cows: SMaP Entry