 Pairs may breed alone or in loose groups . In South Africa , nests may be within 50 m ( 160 ft ) of each other , and breeding densities of up to 13 @.@ 7 nests per square kilometre ( 35 @.@ 5 per square mile ) have been found in Louisiana . The nest , 19 – 26 cm ( 7 @.@ 5 – 10 @.@ 2 in ) across , is made from plant leaves and stems and has little or no soft lining . It is usually built in dense vegetation and close to water , but sometimes in tree holes . In India , the use of tree holes , and even the old nests of raptors or crows , is much more common than elsewhere . Eggs are laid at roughly 24- to 36 @-@ hour intervals , starting before the nest is complete , resulting in some losses from the clutch . They are whitish and on average measure 53 @.@ 4 mm × 40 @.@ 7 mm ( 2 @.@ 10 in × 1 @.@ 60 in ) and weigh 50 @.@ 4 g ( 1 @.@ 78 oz ) . The clutch is usually around ten eggs , but other females sometimes lay into the nest , so 20 or more may be found on occasion . Eggs may also be added to the nests of other species , like ruddy duck . 
