Author: Simon Bruslund

Author Tom Squires, PhD Candidate at Manchester Metropolitan University, UK

The Bali myna (Leucopsar rothschildi), so emblematic of the island it is endemic to, has been reintroduced to Bali Barat National Park over the past 30 years in attempts to re-establish a wild population. The population of this highly sought-after songbird was decimated from the mid-20th century onwards by trapping to supply the insatiable demand from the cagebird trade. In support of latest reintroduction efforts, an ecological monitoring project has been undertaken, its goal being to gather detailed information on the wild population and share this with the national park for the benefit of important ongoing conservation activities. Such monitoring can provide valuable insight regarding the species’ ecology, demographics, dispersal, and long-term population viability. Much of the data required for this analysis have been collected over the past 12 months, but fieldwork is still ongoing. Here, we provide a summary of the monitoring work we have been carrying out.

Population Distribution and Abundance
For the past 12 months, Tom and research assistants Panji Gusti Akbar, Muhammad Arif Romadlon and Aldina Rahmadhani, mapped the occurrence of Bali myna within and surrounding Bali Barat National Park. Well over 1,000 encounters with Bali myna were recorded, giving us a good idea of where birds spend their time, as well as daily and seasonal variation in habitat use. With this information, we will be able to determine which areas are most likely to support a range expansion, and areas outside the national park that birds might be expected to disperse to in the future.

Habitat Preference and Suitability
To complement the bird occurrence data, we undertook an extensive park-wide habitat survey, recording habitat structure and vegetation characteristics in 10 m radius plots. Muhammad and Aldina, recent Indonesian graduates with a primary interest in botanical field research, joined the project and after an instructive week with Bali Barat’s botanical expert, Bapak Putu Yasa, amassed an impressive dataset of >700 habitat plots across the national park and in the area immediately surrounding it. These data will be used to generate an up-to-date supervised habitat classification for Bali Barat National Park and its surrounds, as well as to examine more detailed habitat associations of Bali myna.

Productivity
Nestboxes have been installed at each Bali myna release location to offer birds safe and easy access a nesting site. This has the added benefit of enabling relatively straightforward monitoring of breeding productivity, although it is still demanding work that takes time and patience throughout the breeding season, and an in-depth understanding of behaviour to ensure disturbance to birds is minimised. Mas Untung, Andri and Sasmita have taken on this task of detailed monitoring of the nestboxes and natural nest cavities used by Bali myna in close cooperation with national park staff. They are collecting extremely valuable breeding data, and with the help of an endoscope (or “snake camera”), have been able to collect some of the first definitive data on clutch size, numbers of chicks, and nesting success from wild birds. This work will continue until the end of the breeding season, thought to be around May/June, although some birds may actually continue to breed after this period, one reason for this important work to be a continual effort.

Above Untung and Andri are in the process of checking a nest with an endoscope

Survival and Movement
Ever since the first aluminium ring was attached by Hans Christian Cornelius Mortensen in 1899 to another member of the Sturnidae, the European starling, modern-day bird ringing has helped us determine how long birds live for and where they go. The use of coloured plastic rings now means that birds need not be re-caught to know their identity, reducing disturbance. Using these methods in Bali Barat on a sub-sample of the Bali myna population has helped us to understand the movement of birds between release sites – indeed, we have confirmed that birds are moving more than we expected! Furthermore, through continual monitoring and repeated registrations of the same birds over time, we are able to measure the birds’ apparent rate of survival, an important metric required to help build a population viability analysis.

With the end of the current breeding season will arrive the final data required for the planned analysis to begin and for results to be published and shared with the national park, project partners, and wider scientific community. Completion of this initial analysis is anticipated by July 2020.

This work has been made possible thanks to funding from the EAZA Silent Forest campaign, and Tom also receives funding from Chester Zoo and MMU as part of his PhD.

Authors Sunny Nelson, Stuart Marsden & Tom Squires

Sunny (Lincoln Park Zoo) along with Tom and professor Stuart from Manchester Metropolitan University recently visited Bali Barat National Park, Bali Safari & Marine park and Nusa Penida to develop the Silent Forest Campaign pre-selected Project for Bali Myna conservation. We concentrated on community projects – the rationale being that local communities need to be on board if conservation efforts to bring the species back to the wild are to succeed long-term.

First stop was to work with our friends from Bali Barat National Park. Talks with park director Pak Agus Krisna and his staff were fruitful and we hope they will pave the way for some imaginative outreach projects with local primary school children all centred around Bali Mynas. Monitoring of the Bali Myna releases at BBNP has shown that some of the offspring of released birds are on the move – and this movement is tending to be towards the eastern parts of the park and even to community areas outside of the park.

Another project component we are currently planning is to work with hotels and other businesses near the tourist resort of Pemuteran. If hotels can be persuaded to put up nest boxes and provide feeding stations for the birds, then this might be a win-win situation with the mynas finding a safe haven outside the national park while local businesses promoting themselves to tourists as a ‘Jalak Bali-friendly community’ (Jalak is the Indonesian word for starling).

Here Sunny is discussing and learning about local community projects

Next stop for the team was a visit to the new Bali Myna release site at Bali Safari & Marine Park. We were so impressed with the release efforts of Dr. Kadek and his team, all backed up with some great outreach efforts with local communities led by Dayu Ari. It will be of course some time before it is known whether this release has ‘taken’ or not, but early signs are good.

Searching for Bali Mynas on Nusa Penida with the FNPF team.

Our final stop was the island of Nusa Penida, where the inimitable Dr Bayu and his team at Friend of the National Parks Foundation (FNPF) have been working for more than a decade on Bali Myna releases. This release is going well with several pairs observed on the island. We expect to support some work on both monitoring and assessing community engagement needs naturally depending on future funding opportunities.

The EEP Committee has approved the name change of the EAZA Passeriformes TAG into “EAZA Songbird TAG” as per 6 January 2020.

During the last TAG meeting in Valencia we proposed this name change to the participants with the argument that the scientific order name is not always really user friendly. Also, sometimes it tough to stay scientifically accurate as a “order name” might indicate because taxonomy changes happen, or practical accommodations has to be made for certain species to be integrated in a different TAG than the name might indicate.

Currently the EAZA Songbird TAG covers “only” species of the order Passeriformes which is already the largest group of birds with more than 6600 different species distributed throughout the world.

Under the TAG the working group on Asian Songbirds threatened by trade was instrumental for initiating and developing the Silent Forest Campaign between 2017 and 2019. This working group will continue its important work as a part of the Songbird TAG under the name Silent Forest Working Group. Members of this group routinely meets twice a year, mostly in conjunction with another EAZA meeting.