Using acoustic monitoring to understand human impacts on Amazonian wildlife

Posted by Oliver Metcalf

It was dawn on my first morning in the Amazon. 24 hours earlier, I had been walking through the snow in Manchester to catch a bus to the airport, now I was stood 50m up on a scaffolding tower, soaring above the rain forest canopy, listening to the forest come alive. We had been so keen to get here that we hadn’t slept, briefly dropped our bags at the accommodation and then headed straight out on dirt roads, so that my first sight of Brazil should be deep in the heart of pristine rain forest. Moments earlier, there had only been the occasional mournful whistle of a tinamou and the otherworldly, nightmare-ish growl of howler monkeys, but now the dawn chorus had started and songs and calls came from all directions.

The Tapajos National Forest at dawn – the sun glowing red from the smoke of surrounding small wildfires (Photo: Oliver Metcalf)

Alex Lees, my PhD Director of Studies, rattled off the species names like a football commentator during a particularly frenzied passage of play, recording each species on eBird as he pointed them out – cryptic forest-falcon, black-tailed trogon, rufous-winged antwren, three-striped flycatcher - before long my head was spinning and I couldn’t keep up. Zoning out of trying to identify individual species, I took a minute to feel this new environment, to indulge the surreal feeling of being so far from home, in the world’s greatest rain forest. But something jarred with the image my eyes were providing of pristine wilderness, there in the background of sensory overload was the acrid, lingering smell of smoke. 

Above: Undisturbed forest looks dark because of an intact canopy layer. Below: Burned forest lets in more light as dying trees open up gaps in the canopy. Many species in the Amazon are photophobic and won't cope well with these brighter conditions (Photos: Oliver Metcalf)

The ecological and environmental impact of deforestation in the Amazon are well known and well publicised. Many of us have watched news reports of falling canopy giants accompanied by the soundtrack of screaming chainsaws, or learnt in geography classes about the harm slash-and-burn agriculture can cause. However, the high visibility of this environmental destruction has led to the Brazilian government taking action, and the rate of deforestation has declined since their 2004 peak (albeit with some recent increases). Various sustainable forestry initiatives have been used to slow the rate of deforestation– including extractive reserves which permit selective logging. These allow large areas to be set aside ostensibly for conservation purposes whilst still generating income from extractive industries.

Delights and dangers of Amazonian fieldwork. Above, the lovely Wing-barred Piprites Piprites chloris (Photo: Nárgila Moura); Below, a Fer-de-lance Bothrops atrox sharing the trail with us (Photo: Oliver Metcalf)

Large swathes of Amazonia are now subject to disturbance from selective logging and fire, yet our understanding of the impacts of such disturbance on biodiversity is still limited (Barlow et al., 2016). One of the most harmful consequences of selective logging is an increase in forest susceptibility to wildfire, exacerbating an already volatile situation caused by drought and climate change. In fact, during the El Nino events of 2015-2016, there were so many wildfires in the Santarem region (where my study site is located), the area was responsible for driving a large rise in atmospheric carbon dioxide levels. Fire can have devastating and immediate impacts on tropical forests. During my PhD, I will be working with the Sustainable Amazon Network, a transdisciplinary research consortium that studies the effects of disturbance on all levels of the rain forest environment and its biodiversity, as well as the best means to avoid and mitigate these impacts. I will be working in a protected area that allows selective logging, the Tapajos National Forest (FLONA) in Para state, Brazil, to establish the impact of logging and fire on the biodiversity of the park, large areas inside and outside of the reserve were burnt in 2015-2016. Consequently, my study design will focus on establishing the impacts of disturbance on biodiversity across a degradation gradient – comparing areas that are variously undisturbed, logged, burned or logged and burned.

Layard's Woodcreeper Lepidocolaptes layardi (Photo: Alex Lees)

Technical innovations in measuring biodiversity in the rain forest

Of course, comparing ‘biodiversity’ in such a diverse and challenging region is easier said than done. Trekking from point count to point count, transect to transect can be extremely hard work, time consuming and even dangerous, with a preponderance of poisonous snakes, bullet ants and wasps. Even if everything goes to plan, observing wildlife can be extremely difficult, frogs hide in hollow logs, birds feed in canopies 50m above and mammals run for cover well before a surveyor can clap eyes on them. This means that the best way to survey a wide range of species in the Amazon is to listen for the sounds they make. Even then, some species will only call at dawn and dusk–particularly birds such as forest falcons and tinamous, whilst others will wait for the dead of night or the heat of the day before making noise. This means that any attempt to survey all species using point counts or transects will inevitably miss a range of species, unless repeated a huge number of times across the day.

Some of the wildlife we hope to record; Above: an Amazonian pygmy owl Glaucidium hardyii, Below: a white-cheeked spider monkey Ateles marginatus (Photos: Oliver Metcalf)

Instead, I will be using passive acoustic recording devices from Frontier Labs to record continuously for a week at each of 40 transects spanning the degradation gradient, once in the wet and once in the dry season. These devices allow a huge amount of data to be collected with comparatively little time required in the field, and have previously been used to survey a wide range of species, as well as anthropogenic disturbance events such as chainsaws and gunshots. The difference here is that I will aim to detect the vocalisations of all the species within each transect, including birds, mammals, frogs and insects (although many of the insects will be morphotyped rather than identified to a species level). This will allow a greater understanding of how entire forest communities are affected by disturbance, rather than particular species within it.

The widespread Forest Elaenia Myiopagis gaimardii should feature on the 'tapes' (Photo: Nárgila Moura)

Of course, analysing the huge amounts of data collected (over 20 terabytes) is a challenge in itself, and it would be impossible to manually listen to all of the sound data that will be collected. I will instead be using Tadarida, a program that utilises machine-learning algorithms, to automatically detect vocalisations. This is a painstaking process in which I must iteratively train the program to recognise each of the call types present in the data. To start with, I will focus my attention on the nocturnal and crepuscular communities, as these are the least studied and hardest to survey using traditional techniques – and the simpler soundscapes will give the automated recognition software the best chance of performing well. Even still, I will have my work cut out for many months to come! After the training process, the program will look through the entire dataset for further similar calls allowing the creation of a database of the presence or absence of a wide range of taxa, equivalent to many hundreds of repeat transect surveys.

A spectrogram of a small section of the data so far recorded – most of the marks below 6kHz are bird calls, whilst the dark line in the centre is an insect being very noisy!

This will allow us to understand, at a broader scale than ever before, how communities respond to the disturbance gradient, and gain a through understanding of how the precious, unique biodiversity of the Amazon is being impacted by ongoing human disturbance.
 
Oliver's PhD at MMU is supervised by Dr Alexander Lees, Professor Jos Barlow (University of Lancaster) and Stu. The PhD is a component of Rede Amazônia Sustentável (RAS), a multidisciplinary project on sustainable land use in the Amazon. 

Myna miracle needed for Indonesia’s threatened starlings

Posted by Tom Squires

Trade-driven extinction threatens a growing number of Indonesia’s songbirds, as unsustainable trapping to supply the cagebird trade continues seemingly unabated (Eaton et al. 2015). In 2016, 19 of Indonesia’s bird species, all bar one songbirds, were uplisted to a higher extinction risk category on the IUCN’s Red List for birds. Indonesia is home to ten Critically Endangered species on the brink of extinction, primarily because of trapping. All except the helmeted hornbill Rhinoplax vigil, a species long-exploited for its ‘ivory’ casque, are traded as songbirds. In response to the significant and growing threat of extinction facing Southeast Asia’s songbirds, the first Asian Songbird Trade Crisis Summit convened in 2015 to devise a conservation strategy to tackle the issue.
 

Manchester Metropolitan University (MMU) and Chester Zoo developed two research projects that will focus on Indonesia’s cagebird trade (see Stu’s previous post). Tom’s 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. Here, he introduces his research project and outlines its objectives.

Bratang bird market, Surabaya, East Java - not only can you buy songbirds, parrots and owls, but also reptiles, amphibians and mammals. (Photo: Tom Squires)

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.

Black-winged myna populations have plummeted in response to increased trade demand. They are a next best replacement for the coveted, but hard to obtain, Bali myna. (Photo: Jonathan Beilby)

My project will include ecological studies of two of Indonesia’s most endangered birds, the black-winged myna Acridotheres melanopterus and Bali myna Leucopsar rothschildi, both members of the starling family. The black-winged myna was formerly quite common in the lowlands of Java and northwest Bali, but in recent decades has become almost impossible to find, except in local bird markets (see Nijman et al. 2017). Nevertheless, small populations persist at up to ten locations, and current actions – including a reintroduction at Taman Safari in West Java and a captive breeding programme to enable further releases – provide hope of a species recovery. I will carry out fieldwork at one of the most important remaining sites for the species, 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.

Bekol savannah at Baluran National Park supports one of the largest remaining populations of black-winged myna. (Photo: Tom Squires)

Bali myna: king of cagebirds, this species may have been trapped to extinction in 2006  (Photo: Jonathan Beilby)

The iconic Bali myna, Bali’s faunal emblem and its only endemic bird, is highly coveted as a cagebird for its song, pristine white plumage that has symbolic associations with peace, and rarity. Consequently, the Bali myna has suffered a steady population decline since the 1960s and 70s, when its popularity as a cagebird reached its pinnacle, with hundreds being exported overseas annually. Habitat conversion, from monsoon forest to agricultural land, has certainly contributed to this decline, but in part only because it made birds more accessible to poachers. Despite being listed on Appendix 1 of CITES (prohibiting international trade) and protected under Indonesian law since 1970, numbers in the wild continued to diminish until a possible extinction in 2006 (Jepson 2015). Since then, conservation efforts and releases of Bali myna at various locations on Bali and its neighbouring island of Nusa Penida mean that they can still be seen in the wild, albeit in small numbers.

A released Bali Myna seen using one of the artificial nest-boxes provided (Photo: Tom Squires)

The number of released Bali myna in the wild probably remains at around 100, suggesting that conservation efforts have been hampered. It is unclear what the outcome of all releases of birds has been, but is highly probable that birds have suffered continued illegal poaching for the cagebird trade, and birds may have also failed to reproduce. I plan to initiate a radio tracking study to follow the fortunes of reintroduced Bali myna closely at release sites. Daily monitoring of released birds, for the lifetime of the radio tags, will be carried out to collect data on post-release dispersal, mortality, feeding behaviour and habitat-use. Additionally, birds will be colour ringed to facilitate a long-term monitoring project of the releases, hopefully with collaboration from Indonesian partners. This post-release study is urgently required to establish patterns of behaviour following release and ultimately optimise conditions for future releases.

The blue-winged leafbird Chloropsis moluccensis may grow in popularity similar to its cousin, the greater green leafbird C.sonnerati, whilst the Javan nominate of crested jay (or jay shrike) Platylophus galericulatus is already being substituted by the Sumatran and Bornean subspecies coronatus (in photo; Photos: Jonathan Beilby)

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, an objective of this project is to investigate broad patterns of change in the range of species affected by trade. To achieve this, I will build species distribution models (SDMs) 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. This will serve as a predictive tool to pre-empt areas of concern for species that begin to emerge in large numbers at bird markets.

Living rent-free: the endemic Java sparrow is clinging on in unlikely places, like at this hotel in Yogyakarta city centre, Java. (Photo: Tom Squires)

An interesting feature of the distribution of some species threatened by trade is that they appear to thrive in some unusual locations, either because they have so many visitors that trappers cannot covertly take birds, or security arrangements exist which indirectly protect birds. A couple of examples include the Java sparrow Lonchura oryzivora that I saw in Yogyakarta, roosting under the eaves of an exclusive hotel, and the Bali myna that were out in the open near a temple and very conspicuous to visitors of the site. I will review as many of these sites as possible to understand why species persist in these locations but are missing from others, and discover what is happening in terms of population dynamics. I will carry out bird surveys and collect environmental and socio-economic data in and around the sites supporting target species including Java sparrow, Javan myna Acridotheres javanicus and ruby-throated bulbul Pycnonotus dispar. Assessing these sites and searching for sites with similar attributes could help find locations for future species reintroductions, and possibly even new populations of threatened species. This work will certainly help document the biodiversity value of such sites and may highlight a need to formalise their protection wherever possible.

This project is joint-funded by MMU and Chester Zoo and is a collaboration between these organisations, Burung Indonesia (Indonesia’s BirdLife partner), and Universitas Indonesia. Tom’s supervisors are Stu, Nigel Collar (BirdLife International), Andrew Owen (Chester Zoo), Christian Devenish (MMU), Simon Tollington (Chester Zoo), Huw Lloyd (MMU) and Nurul Winarni (Universitas Indonesia).

References

Collar, N.J. & Butchart, H.M. (2014) Conservation breeding and avian diversity: chances and challenges. International Zoo Yearbook 48: 7-28

Eaton, J.A., Shepherd, C.R., Rheindt, F.E., Harris, J.B.C., van Balen, S. (B.), Wilcove, D.S. and Collar, N.J. (2015) Trade-driven extinctions and near-extinctions of avian taxa in Sundaic Indonesia. Forktail 31: 1-12

Jepson, P.R. (2016) Saving a species threatened by trade: a network study of Bali starling Leucopsar rothschildi conservation. Oryx 50: 480-488

Lee, J.G.H., Chng, S.C.L. and Eaton, J.A. (eds.) (2016) Conservation strategy for Southeast Asian songbirds in trade. Recommendations from the first Asian Songbird Trade Crisis Summit 2015 held in Jurong Bird Park, Singapore, 27-29 September 2015

Nijman, V., Sari, S.L., Siriwat, P., Sigaud, M. & Nekaris, K.A-I. (2017) Records of four Critically Endangered songbirds in the markets of Java suggest domestic trade is a major impediment to their conservation. BirdingASIA 27: 20-25.

Salone's gangs: Children of a civil war

Posted by Amy Marsden

For three months, I lived in Kenema, in Sierra Leone’s Eastern Province, as part of the ICS scheme. Our group was mainly involved in peaceful conflict resolution discussions with members of violent street gangs and young people in the four different communities. Over the course of 12 weeks, we covered everything from Ebola, to mental health, and the civil war in our group discussions.

 
Sierra Leone has a long history of disruption, disasters and violence, the most recent of which being the devastating landslides in Freetown. However, it is arguably the eleven year civil war (1991- 2002) that caused most chaos and that is almost as prevalent today as it was 15 years ago. During this period of war, war crimes were unabashedly committed and countless human rights were breeched. It is thought that at least 50,000, if not as many as 300,000 lives were taken. A prominent feature of this war, as with some other African conflicts, was the proportion of children involved in the fighting.

The aftermath of the war is still painfully prominent in Salone society, both in its people and its geography. Deep into the Kambui hills and those of the Gola rainforest, you can still stumble across rebel ammunition and weaponry; both of which can be easily found in the Kenema black market. If it isn't enough of a reminder being in the shadow of rebel hideouts up in the hills, you can see the effect of the war in Kenema's people.

Child soldiers. Above - the reality; below - J-Boy and Small Mikey play with wooden guns in the yard (Photo: Amy Marsden)

The stories of burned villages, mass executions, war rape, child soldiers and cannibalism lives on brutally in the minds of survivors, now 15 years since the war ended. It isn't any wonder that there are many suffering with severe mental health problems because of what they experienced. One of the older participants in our group sessions in a community called Nydandeyama, was a young man during the civil war. He told us of the joy in which the rebels executed people, and the songs they sang before they did. He remembers the hysterical fear he felt when hearing one of these songs as he was stopped at a rebel checkpoint with his mother. He felt sure that if they had not been hidden in the back of the van, they would have both been killed.

As UK volunteers, we couldn't help but wonder at how these kind of experiences had affected people. With only one mental health nurse in the whole of the country, and no NGOs working in this area, there is no help for those who desperately need it. When we spoke to people about the war in our talks, they were understandably reluctant to open
up. Sierra Leonians don't talk about the civil war, it seems that they prefer to pretend it never happened, potentially providing a breeding ground for further emotional and psychological issues. However, some seemed relieved to unburden themselves from the pressure of this secrecy. Many spoke of their personal grief; losing mothers, standing as their homes burnt to the ground. However, it is arguably the long- term effects of the war that have created the biggest impact on modern Salone society. This is primarily because of what the children of Sierra Leone experienced in those eleven years at war.

Small Mikey doing headstands on the dining room table (Photo: Amy Marsden)

Kenema’s Street Gangs


It is the children (now aged between 20-40) who lost parents and senior members of their families who have grown up without essential support systems. Those who did not find this support in religious or community groups formed or integrated into street gangs, known in Sierra Leone as ‘cliques’. This could have been to simply to feel a sense of community and togetherness they no longer had within a family. It seemed that the bonds they shared and the power they felt from having such a support system could have been a small comfort against the losses they experienced in their childhoods. Despite how charming and seemingly childish these men are, the vast majority of gangs are involved in serious violence, the most powerful having mafia- style authority over their communities. Although most of the younger men involved in the cliques have typical jobs, like okada drivers (giving people lifts on their motorbikes or mopeds), the older men seem to be a part of something a little more suspect. Some of them are part of the diamond trade, one that is still as dishonest and unsafe as ever. Many diamond traders and labourers are part of street gangs; helping to find, sell and trade both illegally and unethically sourced gems. Sierra Leone is the fourteenth poorest country in the world, and for young adults and children living in poverty, these wealthy gang members must be inspirational for some of them. Young people in Kenema are desperate for jobs or some source of income, and from the outside, these ‘cliques’ seem to provide that, despite their members being frequently in and out of prison for violent crime.

Howareyou playing in unfinished house (Photo: Amy Marsden)

During the war, boys as young as 5 were taken from their homes to fight. These children, now men, are less likely to be involved at all in Salone society, or even in street gangs. They were subject to such extreme and constant violence that they were expected to become immune to  it. Many were forced to kill their own families, because, in theory, if you've killed your own parents, who will you not kill? These child soldiers were also forcibly given drugs and strong alcohol as a further brainwashing technique, to keep them inhumanely detached from their actions. Because of this, there are many survivors today with chronic drug and alcohol issues, either unable to break from the addiction that engulfed them during their time in the war; or because they are using these substances as a coping mechanism. These young people are often isolated, or isolate themselves from society. 

One would think that the atrocities seen during the Salone civil war would be enough to persuade the country to be peaceful for a long time afterwards. However, in the community named ‘Burma 4’, many of the people we spoke to believed that another civil war was inevitable. The government is still selfishly corrupt, and those it is meant to be helping are still desperately trying to carve themselves a life out of poverty. Our community discussions indicated that many people across Kenema believed this to be the case, that a second conflict was on its way, as shortly as 15 years after the last ended.

Amy is about to start her BSc in International Disaster Management and Humanitarian Response at the University of Manchester.

Understanding demand for songbirds in Java

Posted by Harry Marshall

Back in February I attended the Asian Songbird Crisis Summit in Singapore, as a prospective PhD student soon to begin working under the supervision of Stu, Nigel Collar (Birdlife), Andy Moss (Chester Zoo), and Alex Lees (MMU). My research is being funded by Chester Zoo and MMU, and will be a collaboration between the aforementioned institutions, Burung Indonesia (the BirdLife partner in Indonesia), and Universitas Atma Jaya Yogyakarta.

Where it all began: The ASC in Singapore, a stand-out talk by Madelon Willemson from TRAFFIC (Photos: Harry Marshall)

South-East Asia is currently facing an avian extinction crisis driven by a huge volume of domestic and international trade in wild birds (Nijman, 2010; Eaton et al., 2015). Indonesia in particular, is considered a central hub for trade, typified by recent evidence demonstrating how domestic trade is driving major population declines in wild birds in Sumatra (Harris et al., 2016). Moreover, trade is considered a significant threat to at least 28 globally threatened species with a range that includes Indonesia (Eaton et al., 2015). As with many conservation issues, the full consequences of this crisis for biodiversity and ecosystem services remain poorly understood. My research is therefore aimed at understanding the characteristics of demand for songbirds, and using this information to investigate and identify measures that will reduce the impact on wild bird populations and improve sustainability of the industry.

Pramuka bird market on a rainy day...(Photo: Harry Marshall)

Bird-keeping in Indonesia is no recent phenomenon, keeping a bird in a cage is one of the five traditional symbols of Javanese knight (known as Kukila), and has been apparent for centuries. However, in the last 20-30 years there has been an explosion in popularity of singing competitions, whereby hobbyists come together and let their birds sing under the watchful eyes of judges, who rate birdsong on a number of different aspects. Since the turn of the century there has been a reduction in the number of birds imported into Indonesia (due to avian influenza), consequently native species from across the archipelago are being targeted to supply demand and some have already started disappearing from their native ranges. As species have become scarcer within Indonesia there is a growing number of people dedicating themselves to breeding birds commercially, however, evidence is inconclusive as to whether captive breeding is in fact reducing the impact (of the trade) on wild bird populations (Eaton et al., 2015; Burivalova et al., 2017). The shifting context of bird-keeping (from Kukila to singing competitions) demonstrates the complexity of demand, and how the biological impact is tied to changes in the cultural, political, and economic contexts. Indeed, not only is bird-keeping important culturally, economically the industry is worth around $80 million a year.

Examples of singing contests held all over Java, practically on daily basis (Photos: Harry Marshall)

We have developed a survey to gather data on the bird-keeping habits of respondents, alongside their perceptions and beliefs relating to bird-keeping, such as how many, and what types of birds they own, why they keep birds, and whether they see a connection between their birds and wild populations. The surveys will be administered by a team of students from Indonesia and myself. We have chosen study sites (using stratified sampling techniques) to capture an equal share of urban and rural settings within each administrative region in Java. Previous work on this topic has mainly focused on urban populations of bird-keepers, however by including rural localities we hope to uncover a more nuanced understanding of demand across Java.

Left to right: a woman selling bird food at Pramuka bird market; Orange-headed Thrush Geokichla citrina singing in its famous ‘drunken master’ trance; chicks spray painted in every colour of the rainbow to be sold as novelty items for children (Photos: Harry Marshall)

Due to the prevalence of songbird contests across Java, any examination of songbird demand should at some point turn its attention specifically to the numerous hobbyists who take part in, or attend these bi-weekly events. To gain a better understanding of the mindset and culture of hobbyists, in-depth interviews will be used to gather data on their behaviour, and attitudes towards the environment and sustainability. The qualitative methods used will allow a deeper understanding of the situation in Java, and allow a more personal exploration of why keeping and competing songbirds is so widespread. The keeping of birds, just like other hobbies or obsessions is both influenced by our nature and culture, and can even affect society, as this story from the Jakarta Post demonstrates.

A man tends to his lovebird after competing in a singing contest. Flags used to award points to birds during singing contests (Photos: Harry Marshall)

Another dimension to the situation is that as the sale of birds in markets appears to have decreased in recent years (in part thanks to work by NGOs exposing illegal trade), and it is now becoming easier to buy wildlife on the internet. Trade now happens over social media, which isn’t surprising considering Indonesia has one of the fastest growing social media markets, and has the fourth highest number of Facebook users globally. New techniques to monitor trade and trends in demand are therefore urgently required to ensure that up-to-date information is being used to tackle unsustainable supply. An online version of the survey will therefore be made available and shared at singing contests, at universities, and via social media links to allow access to a much larger audience. Another exciting part of my project is using web-scraping to gather information on the habits, perceptions and beliefs of hobbyists, and subsequently using text-mining analytics to determine what key factors influence a bird’s popularity, and what species may become threatened in the future. The results from these online-based techniques will be compared with the results from the face-to-face survey to determine whether they represent a cost-effective means for collecting crucial data on bird-keeping in Indonesia.

The trade in songbirds is moving from the market place to the internet via social media (Facebook & Twitter)

Through combining these various methods (from face-to-face interviews to web-scraping), we aim to build a comprehensive picture of the drivers and factors that are influencing demand for cagebirds, to inform and create evidence-based intervention strategies that reduce the impact on wild bird populations in the long-term. Ideally, these methods will also be replicable to other instances where demand for wildlife is driving populations to the brink of extinction.

References
Burivalova, Z., Lee, T. M., Hua, F., Lee, J. S. H., Prawiradilaga, D. M. and Wilcove, D. S. (2017) ‘Understanding consumer preferences and demography in order to reduce the domestic trade in wild-caught birds’, Biological Conservation. Elsevier Ltd, 209, pp. 423–431.

Eaton, J. A., Shepherd, C. R., Rheindt, F. E., Harris, J. B. C., van Balen, S., Wilcove, D. S. and Collar, N. J. (2015). Trade-driven extinctions and near-extinctions of avian taxa in Sundaic Indonesia. Forktail 31: 1–12.

Harris, J. B. C., Tingley, M. W., Hua, F., Yong, D. L., Adeney, J. M., Lee, T. M., Marthy, W., Prawiradilaga, D. M., Sekercioglu, C. H., Suyadi, Winarni, N. and Wilcove, D. S. (2016). Measuring the Impact of the Pet Trade on Indonesian Birds. Conservation Biology 31: in press. 

Nijman, V. (2010). An overview of international wildlife trade from Southeast Asia. Biodiversity and Conservation 19: 1101–1114. 

Survival ecology for the Yellow-crested Cockatoo

Posted by Anna Reuleaux

Two years ago we attended a workshop on Yellow-crested Cockatoo conservation on Sumba which quickly resulted in several research projects on the species. These research projects funded by Loro Parque Fundación (LPF) and Zoologische Gesellschaft für Arten- und Populationsschutz (ZGAP) were combined into a PhD project for Anna. Here she reports on the first full year of work.

Cockatoos on Sumba inspecting cavity (Photo: Anna Reuleaux)

Yellow-crested Cockatoo Cacatua sulphurea is endemic to Indonesia and Timor Leste, and Critically Endangered. They used to be common throughout the Lesser Sundas and Sulawesi - so common that most older villagers remember being sent to the fields to kill cockatoos in their childhood to protect the corn harvest. Now the cockatoos are so rare that the majority of children have never seen one. Anna’s PhD research aims to provide the knowledge base for urgently needed conservation action for this charismatic species. This includes finding out which of the former cockatoo populations on the Lesser Sundas and Sulawesi still prevail, estimating their numbers, and, most importantly, understanding why the species survived in some locations and died out in others. Examining the productivity of the species and its limiting factors is also essential for understanding viability, or lack of it, within the populations. 

Climbing ladders to access cockatoo nests were still evident on Pantar (Photo: Anna Reuleaux)

Dynamics of the Sumba population

The largest remaining population is found on Sumba with remaining population numbers of the orange-crested sub-species C. s. citrinocristata thought, at the last count, to be in the thousands (Cahill et al. 2005). Burung Indonesia (the Birdlife Partner) and the Fund for Endangered Parrots (a working group of ZGAP) have been working together in a successful long-term public awareness campaign on the island, which has resulted in the creation of a National Park, and poaching coming to a virtual halt on Sumba.

Cockatoo roost on Sumba (Photo: Anna Reuleaux)

In order to judge viability of the population it is essential to understand the demographic parameters and limiting factors for reproduction. Therefore Anna and the cockatoo team of Burung Indonesia have set out to monitor nests during the core breeding season from October to March. Finding active nests has proven difficult, but with increased search efforts in the 2015/16 season, the team found 19 sites that were prospected by cockatoos. Unfortunately only five had eggs laid in them and only one chick fledged. A second single chick was already sticking its head out of the cavity entrance which indicated nearing fledging but on the next visit it looked like this (see Figure below). This cockatoo chick died shortly before fledging, probably due to predation. The skeletonised remains were found in the cavity without the skull.

This cockatoo chick died shortly before fledging, probably due to predation (Photo: Ana Reuleaux)

Cockatoo chicks very much alive and looking forward to contributing to viability of the Sumba population (Photo: Anna Reuleaux)

Frustrated with the unknown causes for nest failures in the first season, the team installed camera traps above the entrances of prospected cavities for the 2016/17 season. Although there was no lack of cockatoo activity around the monitored cavities, only two active nests were found, both late in the breeding cycle, and in previously unmonitored cavities. One of the pairs even fledged two chicks, which is a first in documented nest attempts on Sumba.
Camera trap footage from cavities provided ample evidence of competitors and potential predators. A Long-tailed macaque Macaca fascicularis and an Asian Palm Civet Paradoxurus hermaphroditus were caught looking into a cockatoo cavity, which was luckily empty at the time. Two species of owls used the cavities at night on a regular basis, Short-tailed Starlings Aplonis minor, Great-billed Parrots Tanygnathus megalorynchos and Eclectus Parrots Eclectus roratus occupied sites that were abandoned by cockatoos.

Sumba has an inordinate number of birds species interested in holes in trees - here, the endemic hornbill inspects (Photo: Anna Reuleaux)

Where do other populations remain, and why?

There are six other C. sulphurea subspecies in the Lesser Sundas, on Sulawesi and on three small island groups in the Sulawesi and Java Sea. From March to May this year, Anna went on a ‘road trip’ to survey the populations of C. s. occidentalis on the island chain between Sumbawa and Alor. The largest remaining population of this subspecies is in Komodo National Park and will be surveyed later this year. Between Sumbawa and Alor there are about 70 locations with Yellow-crested Cockatoo records of the past (Threatened birds of Asia and other reports), most of which are certain to be free of cockatoos today. Anna and field assistant Romy from Burung’s Sumba programme set out to survey the most promising of these locations, estimate approximate numbers and find likely sets of conditions allowing populations to survive.

The team found surviving populations in fifteen locations varying in (minimum) size between four and 46 individuals. Evidence for capture of cockatoos was almost universal in all populations: captive birds in the villages, ‘harvested’ numbers reported by locals, or climbing setups still visible on the nest trees. The reasons why these populations are still clinging on are very varied and each place has its own story, but what all have in common is some sort of protection from capture for the pet trade. This may be remoteness, difficult access, a formally protected area, sacred land, exclusive and perhaps sustainable harvesting by one trapper, a climbing accident, and awareness work by NGOs. The amount and normality of trapping still happening was shocking and will surely lead to the extinction of populations in the near future, if nothing is done about it.

Cockatoos survive in areas that are difficult to access, like here on Alor (Photo: Anna Reuleaux)

From July to September Anna will survey the population on Sumba to obtain a much needed new population estimate. This distance sampling survey will try to match previous surveys as closely as possible, and will include other key bird species and habitat parameters. In October, Burung’s Ecologist Benny and Anna will estimate the cockatoo population of Komodo National Park. They will spend 4-6 weeks on the islands of Komodo and Rinca and use distance sampling methods similar to those applied on Sumba.

The Rinca-Robong-Flores daily cockatoo commute (Photo: Anna Reuleaux)

 The Sumba cockatoo breeding season will already have started when Anna and Benny get back to Sumba. The trail cameras will remain in place on the nest trees year round. Hopefully more of the monitored cavities will become active and additional ones can be found. Once the breeding season calms down with chicks starting to fledge, it will be time for Anna to survey the rest of the species’ range for remaining populations: West Timor and Timor Leste, Sulawesi and the islands of Tanahjampea and Wakatobi. The remote population of C. s. abbotti on Masalembo may not need a visit as it is tiny and closely monitored by other organisations.
 

Romy scanning for cockatoos on Pulau Adonara (Photo: Anna Reuleaux)

When the results of all these surveys come together, we will have a much better understanding of the Yellow-crested Cockatoo’s status and be able to identify key areas for immediate conservation interventions and for more long term work. Anna’s PhD, supervised by Stu, along with Martin Jones (MMU), Nigel Collar (BirdLife), and Ani Mardiastuti (Agricultural University Bogor), is due in 2019.

This project is funded by Loro Parque Fundación, Zoologische Gesellschaft für Arten-und Populationsschutz, Fond für bedrohte Papageien and Strunden Papageienstiftung. Currently Anna is supported by a scholarship of the German Academic Exchange Service (DAAD). The work is a close cooperation with Burung Indonesia, particularly with the team on Sumba. Further counterparts in Indonesia are Agricultural University Bogor (IPB, Prof. Ani Mardiastuti) and Universitas Nusa Cendana, Kupang. We are grateful that the Indonesian Government (Ristekdikti and KLHK) gave permission for this research. 

 
References

Cahill, A. J., Walker, J. S. and Marsden, S. J. (2006). Recovery within a population of the Critically Endangered citron-crested cockatoo Cacatua sulphurea citrinocristata in Indonesia after 10 years of international trade control. Oryx 40: 161–167.