Wealth Study of Types Of Rats On Natural And Made In Ecosystems In Bengkulu Province

Rats are cosmopolitan animals because they are able to adapt to environmental changes. These small mammals can be found from primary and secondary forests, plantation areas, rice fields to human settlements. The species richness, distribution, size and dynamics of rats in an ecosystem are determined by external factors such as climate, season, availability of food, habitat / ecosystem type, barrier, type of vegetation cover, soil type, competition, predation and internal factors such as age structure and fertility. This study aims to analyze the richness of rats in natural ecosystems such as secondary forests, swamp forests, grasslands and artificial ecosystems such as palm plantation ecosystems, rubber plantations and rice field ecosystems in Bengkulu Province. The study is located around Bengkulu University, Rojolelo Park, palm plantation of PT. Bio Nusantara, North Bengkulu regency and Mekar Jaya village in Muko-Muko Regency. The study was conducted for four (4) months from April to August 2016. Rats were collected using clamps traps and all traps placed in the study areas used purposive sampling method. The results of the study found five (5) species of rats occupying different ecosystems, namely Rattus tiomanicus, R. exulans, R. argentiventer, R. novergicus and Mus musculus castaneus. Species of R. tiomanicus and R. exulans are cosmopolitan species that occupy all types of ecosystems. R. argentiventer are characteristic in rice field ecosystem, R. novergicus occupies only palm and rubber plant ecosystems while Mus musculus castaneus is found only in palm and paddy field ecosystem


Introduction
The conversion of natural forest ecosystems to artificial ecosystems such as plantations and rice fields is one of the factors causing the loss of the main habitat of mammals in the Bengkulu province. Forest conversion also has an impact on decreasing biodiversity, the formation of small populations that are vulnerable to extinction due to genetic drift and disease or increasing animal populations that are pest (Primack, 1981).
Mammalian that live in natural ecosystems conversion usually already adapted to environmental changes and one of them is rats (Ario, 2010). Rats are a group of small mammals in the rodentia order that have 2700 species throughout the world. Two-thirds of the Rodentia is Muridae family (Payne et al., 2000;Aplin et al., 2003). The existence of rats in an ecosystem can have positive and negative impacts on the environment. The positive impact, mice play an important role in the health of natural and artificial ecosystems because rodentia are the main food for predatory animals such as snakes, eagles, owls, cats, etc. The other roles rats as spreaders of seeds or plant seeds, pollinating agents (Suyanto, 2005 ), while the negative impact is that rats can become infectious pests to human and as diseases vectors such as leptospirosis, plaque,and thyphosa (Ristiyanto, 1994).
The ability to adapt to environmental changes lead to rats can be found in various ecosystems.
Rats can be found in primary, secondary, plantation and rice fields in human settlements (Payne et al., 2000). In addition, rats also fast-breeding animals, they are relatively fast to reproduce so that their population increase in short period of time (Sofyan et al., 2008). Handika (2013) reported that five types of mice found in Singgalang mountain (WestS umatera) such as Rat species that occupy an ecosystem are determined by many ecological factors such as external factors such as climate, season, food, habitat type, barrier, type of vegetation cover, soil and others as well as internal factors such as ability to compete and avoid predation, age structure, fertility and others (Krebs, 1978;Odum, 1971).
Bengkulu has a variety of ecosystems ranging from natural ecosystems such as primary and secondary forests, swamp forests, grasslands to artificial ecosystems such as oil palm plantation, rubber and rice fields. Mice with varied types occupy a variety of habitat types, but so far there has been no scientific information about what types of mice live in these ecosystems. This study aims to analyze the wealth of rats species in natural ecosystems such as secondary forests, swamp forests, grasslands and artificial ecosystems, namely the ecosystem of oil palm plantations, rubber plantations and rice field ecosystems.

Materials and Methods
The study took place in several ecosystems including secondary forests, swamp forests and grasslands in the UNIB and Tahura Rojolelo neighborhoods, the oil palm plantation ecosystem in the area of PT. Bio Nusantara North Bengkulu, the area around UNIB, the area in Mekar Jaya village in Muko-Muko and Tahura Rojolelo, the rubber plantation ecosystem in the Mekar Jaya village area, Muko-Muko, rice field ecosystem in the area around UNIB and Tahura Rojolelo.
The study lasted for four (4) months from April to August 2016.
Direct surveys of natural and artificial ecosystems as described above are carried out to determine representative land and can be used as a study area specifically for the installation of rat traps. Ten (10) fruit traps that have been prepared with bait in the form of roasted coconut are placed at points in the designated location. The method of spreading rod clamp traps at the study site used purposive sampling method, which was based on the signs of the presence of rats in the area such as holes in the soil, traces, paths, remnants of dirt and food debris, fallen trees and weathered, water channels and residential areas (Bismark, 2011;Payne et al., 2000;Cunningham & Moors, 1996). Installation and laying of traps at the research location were carried out in the afternoon starting at 16.00 WIB and re-examined the next morning at 07.00 WIB. The location of each trap is marked with a wooden stick with a red ribbon. Trapping is carried out in five (5) replications where all the traps are installed on the checking day, especially in the afternoon. . The types of mice that were identified were arranged in the inventory list and equipped with photographs. Each type is described using the reference book or guide.

a. Types and Distribution of Mice Collected from Several Types Ecosystem
During the four months of the study in several ecosystem types, 72 individual mice were collected, consisting of five types, namely Rattus tiomanicus, R. exulans, R. argentiventer, R.
novergicus and Mus musculus castaneus (Table 1).  Genus Rattus is a group of mice that have a very wide distribution because of its ability to easily adapt to environmental changes and be able to occupy different ecosystems by consuming a variety of food sources (Suyanto, 2002). Ratus tiomanicus and R. exulans are found in all types of ecosystems because this type is not only easy to adapt to new environments with varied feed preferences but also has the ability to breed quickly (Sudarmaji, 2005).
Rattus argentiventer is only found in rice field ecosystems and does not spread to other ecosystems because the main habitat of this type is the rice field area by making nest burrows in rice fields. These mice live not far from water channels that are overgrown with shrubs or weeds.
Rice plants are the main food and are very popular with these rats so that the population is commonly found in rice field ecosystems (Singleton et al., 2010, Priyambodo, 1995Rahmini, 1997

Conclussion
From the results of a study on the richness of rat species in natural and artificial ecosystems in the province of Bengkulu, it can be concluded: a. Recorded five (5)  c. R. argentiventer is a species that is characteristic of occupying the rice ecosystem, while R.
novergicus is only found in the oil palm and rubber plantations ecosystem and Mus musculus castaneus is found in the ecosystem of oil palm plantations and rice fields.