LIFE AFTER MERAPI ERUPTION: The Return of The Long-tailed Macaque

by : Choiriatun Nur Annisa

November 2010 was the latest big eruption of one of the most active volcano mountains in the world, Gunung Merapi. As the last remaining forest in Yogyakarta, it compromises the habitat for many species including primates. Tlogo Muncar and Tlogo Nirmolo are known as two important habitat of the long-tailed macaque. The Tologo Muncar was affected by eruption, whereas  Tlogo Nirmolo was not. Were they able to survive from the eruption? How’s their life after the devastation? Did they come back to their original habitat?

In February 2011, the author conducted a field work to investigate the population size after eruption. Concentration counts was applied to counts number of individuals, due to very steep topography in the study area. The number of individuals in Tlogo Muncar was higher than before  which should be lower than previous number. Suprisingly, the Tlogo Muncar population even was far higher than Tlogo Nirmolo Population .

vegetation conditions after eruption in Tlogo Muncar

To investigate further explanation why Tlogo Muncar population is higher than Tlogo Nirmolo population, Annisa collected vegetation data using point centered quarter method, collecting evidence of other habitat factors such as water and covers. Five out of 13 feeding species were still found in Tlogo Muncar and either the most frequent also most dominant species were eaten by the macaque. It seems that food is not the limitation factors for the population because this population experienced food supplementation from tourist. Water and covers were also still supporting this population. Although Tlogo Muncar and Tlogo Nirmolo are neighbouring areas, the vegetation in both locations were not close similar, based on the assessment using Sorensen similarity index. Even, the most dominant species and frequent species in both location were different.

Long-tailed macaque population in Tlogo Nirmolo

 Furthermore, Annisa tried to compare population structure. She found that the group size in Tlogo Nirmolo was female deficit. It indicated a high competition between male to get female, and low birth rate. The less number of infant and juvenil in Tlogo Nirmolo was also the evidence. In Tlogo Muncar, the female was still higher than the male. Therefore, the competition would not be as high as in Tlogo Nirmolo. The indication was also from the number of infant and juvenile that was still high (40,8%) in Tlogo Muncar. Another explanation is the ability of long tailed macaque to disperse and avoid effect of eruption. When, the eruption attacked, they might be migrate to somewhere safe as being reported by the official, then came back as soon as it sprouted. From the observation, it seemed that sprouting was not taking long time. Survey on 12 January 2011 in Tlogo Muncar found that some ‘dead’ trees had sprouted. In addition, only one individual was reported death from the eruption. Indicating, that the population of long tailed macaque in Tlogo Muncar was able to survive from the eruption. 

contact: cn.annisa@yahoo.co.id