 The main cause of nest failure among the species is due to nest abandonment , the leading cause of which is inundation from extremely high tides . Parents abandoned 61 % of all nesting starts either during or immediately after extremely high tides . The eggs float out of the flooded nests , or get washed out into the sea by wave action . <unk> parents usually abandon the nest when the water or tidal levels reaches 3 to 8 cm ( 1 @.@ 2 to 3 @.@ 1 in ) above the bottom of the nest cup . Nevertheless , there have been instances where the parents have been observed to transport their eggs to another nest in an attempt to salvage some eggs . However , despite the fact that some nesting sites face high chance of tidal damage every breeding season , American white ibises still continue to nest in these areas because of other favorable conditions such as abundant nearby food sources and low egg predation rates . 
