Musim Mas
Search Menu

By Devane Sharma

With the growing world population, demand for agricultural produce continues to increase. This includes vegetable oils, of which palm is the most-consumed and the highest yielding. Palm oil yields at least 4 to 7 times more oil per hectare than other vegetable crops such as soy, sunflower, and canola. The growth of oil palm plantations to meet this demand over the last half-century has reshaped biodiversity patterns across tropical rainforests in Southeast Asia.

Since its establishment in 2004, the Roundtable on Sustainable Palm Oil (RSPO) has been the leading industry standard and has pushed for improved sustainability standards across the palm oil industry. RSPO requires members to set aside and ‘maintain and/or enhance’ areas of High Conservation Value (HCV) and High Carbon Stock (HCS) along with any rare, threatened, and endangered (RTE) species found within them (Principle 7; RSPO, 2018). There is currently limited understanding of the impact of management and monitoring practices by RSPO members on conserving biodiversity within oil palm landscapes.

Musim Mas’ Effort to Understand Biodiversity Trends in its Conservation Areas

Musim Mas Group is one of the world’s largest sustainable and integrated palm oil corporations and was the first palm major in Indonesia to join the RSPO (in 2004). Musim Mas has undertaken a variety of conservation interventions across the company’s plantations in Indonesia.

Musim Mas’ conservation effort includes forest stewardship, riparian buffer restoration, and active monitoring of wildlife and other environmental indicators within both HCV areas and the surrounding land concessions.

Going beyond conservation alone, the group would like to assess its interventions’ effectiveness to ensure they have the intended positive impacts on biodiversity. Musim Mas set out to understand how biodiversity was responding in the plantations, whether its conservation management plan was helping to maintain or enhance biodiversity, and if there were ways monitoring and management could be improved.

Designing Musim Mas Biodiversity Assessment: A focus on the bird species richness

Musim Mas recorded monthly bird diversity in its concession areas across 14 oil palm plantation estates. A total of 12 years of data was accumulated for the assessment. To analyze the data scientifically, Musim Mas worked with the UK-based South East Asia Rainforest Research Partnership (SEARRP) and scientists at the University of Oxford. Thereafter, the researchers conducted a workshop in October 2022 to discuss the results and recommendations of the analysis with Musim Mas field staff and to identify ways to improve our monitoring and data collection efforts.

Researchers from SEARRP and the University of Oxford at a workshop to share findings from the report with Musim Mas’ staff

Key Findings from SEARRP’s Biodiversity Assessment

  • Bird Species Richness: Biodiversity showed very variable responses across different plantations: decreasing in some, remaining stable in others, and increasing in some places.
  • Consistent and intensive management could be helping: Some of the most beneficial effects on biodiversity were seen in plantations with the most intensive and consistent management to benefit wildlife.
  • Benefits for Rare, Threatened, and Endangered (RTE) species: Patterns of RTE species changed in line with overall species richness- as biodiversity increased in an area, so did the number of RTE specifies
  • Monitoring Protocols: Monitoring programs generally work best with consistent, stable protocols, and regular data analysis can help optimize the effort needed for effective monitoring.

This graph shows the change in survey-level richness over time at Musim Mas’ subsidiary, PT MM. Each dot represents a unique survey. Colour coding represents unique plot locations, helping the reader understand how the addition or removal of plot locations may drive changes in overall species richness. The trend line represents a significant linear trend based on the statistical model.

Bird Species Richness

The study found that the scale over which the analysis was conducted was important and sometimes yielded different patterns of biodiversity change. For example, biodiversity patterns at the sampling plot level could be different from biodiversity patterns when data were analyzed for the whole plantation. Understanding the scale of changes can inform management adaptations.

Lanius schachBentet Kelabu

Conservation Management Could be Helping

While it was not possible to definitively attribute specific management activities to biodiversity changes, it is notable that the two plantations with the most consistent increases at both local and plantation-level scales had undergone some of the most intensive conservation management in terms of the scale of set-asides and restoration, over some of the longest periods. This suggests that over time and with a particular emphasis on conservation management, there may be benefits for biodiversity.

Benefits for Rare, Threatened, and Endangered (RTE) species

The number of Rare, Threatened, and Endangered (RTE) species generally changed in line with overall biodiversity. Therefore, it is likely that management that improves overall biodiversity will also have benefits for species of conservation concern.

Elanus caeruleusElang Tikus

Monitoring Protocols

Managing such a large monitoring system over a long period of time, with changing staff and management, is a challenge. Some aspects of monitoring design and data management limited the extent of analysis and interpretation that could be achieved with the data. There are several areas where monitoring protocols could be improved to increase efficiency and enable effective analysis in the future.

The quantity of data was excellent, and the analysis of sampling efficiency found that frequency could be reduced from monthly surveys to surveys in alternate months (i.e., from 12 surveys annually to 6) while still producing robust estimates of bird diversity. This could leave more time to focus on data management, analysis, and adaptive conservation management.

Researchers from SEARRP and the University of Oxford and Musim Mas staff at the workshop to share findings from the report

Other Important Considerations for Effective Monitoring:

  • Keep plot locations as consistent as possible and carefully record unique ID codes and GPS locations for every plot. Being able to link species records to a specific site is very important because local conditions can significantly influence the species that occur there. Trends in biodiversity over time can only be accurately analyzed if monitoring occurs consistently in the exact locations and the number of plots does not vary dramatically.
  • Have a single list of clearly defined, standard habitat types that are used consistently across all plantations. This is important to draw conclusions about the effects of habitat.
  • Use one taxonomic authority ( is recommended for birds). Check and update bird IDs regularly as taxonomies change regularly. As long as the taxonomy is consistent, comparisons across time, habitat, or plantation can be more easily made.
  • Enter data in “long format” in spreadsheets wherever possible. This format for digitizing data allows all the information about each individual species record to be kept together (such as GPS coordinates, recorder identity, time, date, habitat information, etc.), making it easier to clean data and avoid problems with linking data information for later visualization and analysis.

Sampling effects can significantly impact the results of biodiversity monitoring analyses. Standardizing monitoring protocols, data recording, and management will help greatly to reduce the impact of sampling on biodiversity patterns which can mask actual ecological trends. This standardization will also create efficiencies when preparing the data for analysis.

To quantify the effect of specific management activities, such as tree-planting or patrols, the monitoring design should be carefully considered to provide baseline (pre-management) data, and, ideally, a control (areas which are similar but did not undergo management) to enable comparison. For a robust analysis, monitoring should include not only biodiversity indicators but also measurement of the direct effect of the management that we expect to impact on biodiversity, for example, tree growth or reduction in evidence of hunting. Without these data, it is difficult to attribute biodiversity responses to management versus other factors in the environment.

Researchers from SEARRP and the University of Oxford and Musim Mas staff at the workshop to share findings from the report


Overall, the study’s results showed that, despite a standard management plan being employed across all Musim Mas plantations, biodiversity responded differently in the different locations. This finding indicates that management activities should be tailored to individual plantations, depending on whether patterns of richness are increasing, decreasing, or staying the same, the scale at which these patterns manifest, and considerations about particular environmental conditions such as habitat type and availability and human pressures.