The Vanishing Act: A History and Natural History of the Javan Pied Starling Gracupica jalla.
Ardea, 109(1):41-54 (2021). https://doi.org/10.5253/arde.v109i1.a1
The Javan Pied Starling Gracupica jalla, a recent taxonomic split from Asian Pied Starling G. contra, has disappeared almost entirely unnoticed from its native range in Java and Bali, Indonesia; in a circumstance unique in bird conservation, the only known populations are held in bird shops. To provide an evidence base for any future endeavour to re-establish a population in the wild, we reviewed all published information on the species relevant to its conservation, supplemented by specimen label data, unpublished field notes, diaries and manuscripts. A population in eastern Sumatra (nine localities reported, including Bangka) had obscure origins. The species was widespread in Java (168 localities) and Bali (13 localities), and was described as one of the commonest birds in open, i.e. non-forest, lowland country (records up to 1600 m), having a high tolerance of disturbed habitats, especially agricultural areas, with often large roosts inside city limits. It fed mainly on terrestrial invertebrates and fruits, often consuming plant pests and frequently probing dung. It bred all year but chiefly in response to rains, with apparent peaks in January and May in West Java and April in East Java, building conspicuous untidy nests high in trees and laying mostly 3 (2–4) eggs. The cagebird trade is blamed for the massive decline that abruptly became apparent in the late 1990s and early 2000s, but the use of pesticides in Java and Bali's agricultural environment seems likely to have played an unseen role. Searches are needed to find any remnant populations, along with the creation of a programme of captive breeding and research to identify potential areas for reintroduction.