The Storm's Stork Ciconia stormi in Indonesia: breeding biology, population and conservation

Abstract

Storm's Stork Ciconia stormi is one of the rarest of the storks, regarded as globally endangered and found only in parts of western Indonesia, Malaysia and Brunei. Prior to this study, its breeding biology was unknown and the population status in Indonesia was not well understood. Its breeding habitat, prey, behaviour, voice, eggs and the development of the young are described here for the first time. Breeding biology was studied in 1989 at a nest in south Sumatra, Indonesia. The nest was in the transition zone between mangrove and freshwater swamp forest. Incubation took less than 29 days, and two eggs hatched. Fish 2-7 cm long comprised 67% of the prey for feeding young. The chick was fully feathered at 52-57 days and was seen flying when 57-62 days old. The species is rare in south Sumatra. It occurs in low numbers and flocks of up to seven birds were observed. The density is estimated at 2 0 4 0 birds within 110,000 ha of primary swamp forest. At this density, the population would be below 100 birds in south Sumatra and between 100 and 300 in Indonesia. The species is threatened swamp forest.

Analysis of Reproduction Indicators of the Yellow-Billed Stork (Mycteria ibis)

“…When compared to the painted stork (Rečková et al, 2017), the average length of the eggs of the yellow-billed stork is shorter by 2.50 mm, and Urfi (2011) also reports a longer average egg length in the painted stork -69.58 mm. On the contrary, when comparing the eggs to those of the Storm's Stork from the same family (Danielsen et al, 1997), the eggs of the yellow-billed stork were longer by 5.87 mm.…”

“…Urfi (2011) reports 43.72 mm as then average width of the eggs of the painted stork, which is less by 3,10 mm than what we found in the yellow-billed stork in our study. When comparing the eggs to those of the Storm's Stork (Danielsen et al, 1997), the eggs off the yellow-billed stork were wider by 5.12 mm.…”

Reproductive Characteristics of the Captive Milky Stork (Mycteria cinerea) in Zlin Zoo, Czech Republic

“…The Milky Stork egg was 0.6 mm wider than that of the Painted Stork (Rečková et al, 2017) and the width of the Yellow-billed Stork eggs was almost identical (Rečková et al, 2019). When comparing the size of the Milky Stork eggs with the Storm's Stork from the same family, the Milky Stork eggs were 5.5 mm longer and 5.1 mm wider than that of the Storm's Stork (Danielsen et al, 1997). The weight of the Milky Stork's eggs with other storks was almost identical to 79.8 g of Painted Stork and 80.5 g of Yellow-billed Stork (Rečková et al, 2017;Rečková et al, 2019).…”

Kind to kin: weak interference competition among white stork Ciconia ciconia broodmates

“…Fragmented food is common even in heron species whose nestlings feed mainly from food regurgitated on the nest floor (Werschkul , Fujioka , Marchant , Marchant and Higgins , Hafner et al , Medeiros et al , Mccrimmon et al ). By contrast, storks only seldom fractionate the food bolus, regurgitating a large amount of food onto the nest that can be accessed by several nestlings simultaneously (Hoogerwerf , Haverschmidt , Kahl , , , , , , Thomas , Hancock et al , Danielsen et al , Coulter et al , Klosowski et al , Maheswaran and Rahmani , Falk et al , Urfi ; but see Thomas () and Coulter et al () for adults fractioning the food bolus when caring for very young nestlings).…”