 Recorded dietary items include sago shoots and insects , and it also swallows small stones to help break up its food . It is apparently monogamous , but little else is known of its courtship behaviour . The only known nest was a shallow bowl in the top of a rotting tree stump that was lined with wood chips and dry leaves . The two young chicks were entirely covered in black down typical of precocial newly hatched rails . The estimated population of 3 @,@ 500 – 15 @,@ 000 birds and the restricted range mean that the invisible rail is classified as vulnerable by the International Union for Conservation of Nature ( IUCN ) . Habitat loss has occurred through the harvesting of sago and conversion of the wetlands to rice cultivation , and the rail is eaten by local people . The described nest was in an area frequented by local villagers , so the rail may be more adaptable to habitat changes than had been thought . 
 Recorded dietary items include sago shoots and insects , and it also <a href='uninflect' title='1'><mark>swallows</mark></a> small stones to help break up its food . It <a href='drop_aux' title='2'><mark>is</mark></a>apparently monogamous , but little else is known of its courtship behaviour . The only known nest was a shallow bowl in the top of a rotting tree stump <a href='null_relcl' title='3'><mark>that</mark></a>was lined with wood chips and dry leaves . The two young chicks <a href='uninflect' title='4'><mark>were</mark></a> entirely covered in black down typical of precocial newly hatched rails . The estimated population of 3 @,@ 500 – 15 @,@ 000 birds and the restricted range mean that the invisible rail is classified as vulnerable by the International Union for Conservation of Nature ( IUCN ) . Habitat loss <a href='been_done' title='5'><mark>has</mark></a> occurred through the harvesting of sago and conversion of the wetlands to rice cultivation , and the rail is eaten by local people . The described nest was in an area frequented by local villagers , so the rail may be more adaptable to habitat changes than <a href='been_done' title='6'><mark>had</mark></a> been thought . 
Recorded dietary items include sago shoots and insects , and it also swallow small stones to help break up its food . It apparently monogamous , but lil else is known of its courtship behaviour . The only known nest was a shallow bowl in the top of a rotting tree stump was lined w/ wood chips and dry leaves . da 2 young chicks was entirely covered in black down typical of precocial newly hatched rails . Tdaestimated population of 3 @,@ 500 – 15 @,@ 000 birds and the restricted range mean dat the invisible rail is classified as vulnerable by the International Union fa Conservation of Nature ( IUCN ) . Habitat loss done occurred thru the harvesting of sago and conversion of the wetlands to rice cultivation , and thdaail is eaten by local people . The described nest was in an area frequented by local villagers , so the rail may be more adaptable to habitat changes than done been thought .