Biological richness of Gunung Slamet, Central Java, and the need for its protection

Abstract

Designating protected areas remains a core strategy in biodiversity conservation. Despite high endemism, montane forests across the island of Java are under-represented in Indonesia's protected area network. Here, we document the montane biodiversity of Gunung Slamet, an isolated volcano in Central Java, and provide evidence to support its increased protection. During September–December 2018, we surveyed multiple sites for birds, primates, terrestrial mammals, reptiles, amphibians and vegetation. Survey methods included transects, camera traps and targeted searches at six sites, at altitudes of 970–2,512 m. We used species distribution models for birds and mammals of conservation concern to identify priority areas for protection. We recorded 99 bird species (13 globally threatened), 15 mammals (five globally threatened) and 17 reptiles and amphibians (two endemic). Our species distribution models showed considerable cross-taxon congruence between important areas on Slamet's upper slopes, generally above 1,800 m. Particularly important were records of the endemic subspecies of the Endangered Javan laughingthrush Garrulax rufifrons slamatensis, not recorded in the wild since 1925, the Endangered Javan gibbon Hylobates moloch and Javan surili Presbytis comata, and the Vulnerable Javan lutung Trachypithecus auratus and Javan leopard Panthera pardus melas. Recent forest loss has been modest, at least 280 km2 of continuous forest remain above 800 m, and our surveys show that forest habitats are in good condition. However, the mountain is widely used by trappers and hunters. Given its importance for biodiversity conservation, we discuss different options for improving the protection status of Gunung Slamet, including designation as a National Park or Essential Ecosystem.

Distribution and abundance of threatened and heavily traded birds in the mountains of western Java

“…Indeed, the objective of our fieldwork was either to support moves towards gazetting further areas as formal reserves, or to enhance protection in alternative ways. Several mountains have stood out as particularly warranting protection, including Mount Slamet, the furthest east of our sites, along with Masigit, Kencana, and Tilu (Devenish et al 2022). Key taxa driving these judgements included the Endangered Javan Hawkeagle Nisaetus bartelsi, Javan Leopard Panthera pardus melas, and Javan Gibbon Hylobates moloch, which are among the Indonesian governments "Priority" species for recovery (Mardiastuti et al 2008), but others such as Critically Endangered Rufous-fronted Laughingthrush should also guide decisions.…”

“…How individual sites are best protected is open to debate, but the Indonesian authorities have recently moved away from the idea of further "national parks" towards a more integrated form of land management. This, largely but not wholly in partnership with private sector entities, involves land and forest protection combined with income generation in an "Essential Ecosystem Areas" (EEAs) framework (Sahide et al 2020, Devenish et al 2022. Some of our key species will of course benefit from forest protection and restoration, particularly at the lower sections of mountains which have lost most forest in recent decades (Higginbottom et al 2019).…”

“…We undertook a two-year bird survey across 11 West (plus one western Central) Javan mountains aimed at identifying areas for enhanced biodiversity protection; mammals and certain amphibians were also surveyed (see, e.g., Devenish et al 2022), but will be reported elsewhere. Here we present occurrence data for bird species from 622 km of transects from 37 sites on the 12 mountains, and encounter rate data (groups encountered per hour) aggregated across sites.…”

Correlates of persistence in remnant populations of two Critically Endangered cockatoos

“…NGOs working with local communities to raise awareness for cockatoos and biodiversity have managed to preserve the species at sites on Sumba, Flores and Masalembu (Burung Indonesia, 2011; Nandika et al ., 2020). Although mining is well known for its negative effects on wildlife throughout the world (Gould, 2011; Sonter, Ali & Watson, 2018) and in East Nusa Tenggara itself (Erb, 2016), the security measures associated with such operations can reduce bushmeat consumption (Randriamamonjy et al ., 2015) or bird trapping (Devenish et al ., 2021). A mining operation with its associated security, local economic benefits and an enthusiastic ecologist has contributed to the survival of the only known population on Sumbawa (Yusuf, 2014).…”

Controlling trapping, overgrazing and invasive vegetation is key to saving Java’s last population of the Black-winged Myna

“…Nevertheless, open-country starlings and mynas tend to make medium-distance movements to forage and explore (Bruun and Smith 2003, Minderman et al 2010, Astudillo et al 2019, so protected areas cannot be expected to harbor them indefinitely. In the longer term, therefore, such species, especially if under pressure from trapping, will have to be conserved by management strategies that embrace adaptation and improvisation, taking advantage of the various types of security provided by mining or geothermal operations (Randriamamonjy et al 2015, Devenish et al 2021, religious sites (Colding and Folke 1997), tourist resorts (Moritz et al 2017) and organic farming, all of which may to some extent be leveraged to create appropriate socio-ecological conditions to allow them to survive within working landscapes. Other interventions proposed for exploited wider-ranging species include demand reduction (Burivalova et al 2017, Marshall et al 2020, commercial breeding (Jepson et al 2011) and better enforcement of trade laws (Nijman 2010), and all of these measures could be applied in the case of the Black-winged Myna, whose recovery in Baluran could also be abetted by supplementations of captive-bred birds.…”