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Field research is required to further identify and map taxon distributions, population sizes, and trends in order to better understand the status of taxa, and to guide actions. Understanding population trends in the wild is also key to revising protected species lists internationally and nationally, including the IUCN Red List of Threatened Species. Field monitoring is needed to show if trade has significant effects on wild populations. It is essential that where possible systematic monitoring methodologies are set in place to evaluate threats and trends over time, and to identify emerging issues of concern. Through field work, important sites for priority species can be identified and given adequate protection.

Below are some projects relating to this theme:

Songbird strongholds on Java’s mountains

Java’s many volcanic mountains hold a wealth of endemic birds. Very few surveys have ever been done on most of these mountains, a knowledge gap that needs to be filled, especially as the island’s montane birds are under threat from forest clearance and capture of birds for the cage bird trade. Heavy trapping for the cagebird trade has brought about reportedly precipitous declines in species such as Javan Green Magpie and Rufous-fronted Laughingthrush. Our recent review of ‘the state’ of West Java’s mountains including analysis of forest cover change (Higginbottom et al. 2018) highlighted a series of around 20 mountains/blocks, all needing biological and socio-economic surveys fast. Coupled with this was a need and a desire by Indonesia’s Environment Ministry to consider expanding their protected area network in upland Java to better protect the country’s key species.


This is a four year project coordinated by Burung Indonesia, the BirdLife partner in Indonesia in partnership with Manchester Metropolitan University, which aims to identify priority areas for conservation in the Javan uplands – ones which have important populations of key species and habitats and the conditions under which these can be protected into the future – and to take one or more of these areas right through to designation as official protected areas.


One of the first steps in this pipeline to protection is to conduct socio-economic studies in and around the candidate mountains, and to survey as well as we can the wildlife they contain. The project intends to find out how local communities use the forest and perceive its value and how this might change under protection. We also want to know about patterns of bird trapping and which areas might serve as sanctuaries or release sites for threatened birds in the future. Not least, we need to know which species from a range of taxonomic groups survive on which mountains, where they occur and in what kind of numbers in which habitats.

The project uses a system of week-long surveys at multiple sites within mountains. It employs a mix of controlled and relatively high tech surveys using remote cameras and acoustic recorders arranged along transects, and more extensive ‘quick and dirty’ encounter rate searches for key species. Records from the latter may feed into spatial distributional analyses (such as ENFAs) which will help to identify hotspots for protection at the local level. Data will also yield encounter rates of key songbirds, to assess their current status, to identify strongholds for them, and to form a baseline against which future changes can be gauged.


People: Stuart Marsden, Nigel Collar, Ria Saryanthi, Ridha Junaid, Andrew Owen

Contact: s.marsden [at]

Funders: Rainforest Trust, Chester Zoo, EAZA Silent Forest campaign


Further information on this project can be found at

A re-survey of the Javan White-eye in the Javan Coastal Zone Endemic Bird Area

This is an important project looking at changes in distribution and abundance of one of the key cagebird species in trade within Java. The Javan White-eye was first surveyed at 19 sites along Java’s north coast in 2006 and 2009. This project aims to repeat those surveys as closely as possible around ten years after the original surveys were done. Thus it may be a very useful gauge as to how steep the decline in the species has been, and will help us to identify sites where the species has managed to hold on. This will be useful both in protection of the white-eye in particular, but may also help us to characterise those sites that may retain other key bird species, and why.

People: Bas van Balen, Stuart Marsden, Ria Saryanthi

Contact: bvanbalen001 [at]

Funder: Oriental Bird Club

‘Survival ecology’ of mynas and other heavily-traded Indonesian songbirds

This PhD aims to understand the ecology and management needs of some of Indonesia’s most endangered birds that are affected by trade on the Indonesian islands of Java and Bali. Unsustainable trapping to supply Indonesia’s domestic cagebird trade involves millions of wild birds annually and threatens an ever-increasing number of species with extinction (Eaton et al. 2015). Seven of Indonesia’s Critically Endangered songbirds affected by trade are endemic to Java and Bali. Java, the most populous of the Indonesian islands (145 million inhabitants in 2015), lies at the heart of Indonesia’s cagebird trade, due to its deep-rooted songbird-keeping culture and the rising popularity of songbird competitions. The project will include ecological studies of two of Indonesia’s most endangered birds, the black-winged myna Acridotheres melanopterus and Bali myna Leucopsar rothschildi. Fieldwork at one of the most important remaining sites for the former, Baluran National Park in East Java, to estimate population size and study aspects of black-winged myna ecology. Fieldwork will also be replicated at other sites where black-winged myna are known to be present. The information gleaned will help guide in situ conservation efforts for the species. Around one year of fieldwork on Bali Myna is planned within Bali Barat National Park. This will involve assessing habitat use, expansion of area of occupancy by released birds and habitat suitability across the park.

Indonesia’s cagebird markets are dynamic and trends of popularity in groups of species can change quickly. Some species, such as the greater green leafbird Chloropsis sonnerati, are beginning to exhibit worrying population trajectories that could go on to replicate historic declines of Critically Endangered species like the Bali myna (Eaton et al. 2015). Thus, another objective of the PhD is to investigate broad patterns of change in the range of species affected by trade. To achieve this, species distribution models (SDMs) will be built for a suite of traded species. Locations of species occurrence, obtained from citizen science datasets such as eBird, will be related to environmental (e.g. land-use and climate) and trade-pressure related variables (e.g. human population density and distance to bird markets), to determine which factors best predict species distribution. It is hoped that results will indicate where species are exposed to high levels of trapping pressure, as well as areas where trapping pressure is relatively low; these could be the best areas within which to search for ‘sanctuaries’ for future species reintroductions.


People: Tom Squires; Stuart Marsden, Nigel Collar, Christian Devenish, Nurul Wirnani, Andrew Owen

Contact: TOM.SQUIRES [at]

Funding: Chester Zoo and Manchester Metropolitan University, Oriental Bird Club


Further information on this project can be found at

Integration of habitat loss and poaching pressure to assess threat levels of Sundaic birds

In a recent study that drew from the combined experience of geographers, modelers, conservationists and field ornithologists (Symes et al. 2018), we evaluated the latest satellite imagery from the Sundaic region of Southeast Asia to map forest loss and integrated habitat decline with differential, species-specific effects of poaching activity to arrive at extremely precise estimates of endangerment for Southeast Asia’s rainforest birds. The study culminated in proposals for upgrading and downgrading the threat status of dozens of bird species, which we hope will be considered in future reclassification exercises of Sundaic birds. 

The original study – published in Nature Communications – can be found here (under Symes et al. 2018):

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