Latest news from the Wae Wuul Protection Plan for Komodo Dragons January 17, 2008Posted by ekologi in Uncategorized.
Tags: Chester Zoo, community awareness, Komodo dragon, wae wuul
add a comment
Latest news from the Wae Wuul Protection Plan for Komodo Dragons
source from Chester Zoo’s Action for the Wild
Posted: 02/07/2007 The Wae Wuul Protection Plan is based on the island of Flores in Southeast Indonesia. In 2001, population densities of Komodo dragons on this island were estimated at 1 individual per 20 hectares. This is a marked decrease from surveys in 1991, probably caused by human-related pressure on natural habitats in the Wae Wuul Reserve, through poaching, cultivation of land and collection of firewood.
The 2006 Komodo dragon conservation programme commenced in the dry season in July 2006. Administration issues with the local authorities were dealt with in July, with staff from Komodo National Park and the Nature Resources Conservation Office working on a long term agreement regarding joint management of the Wae Wuul Reserve. A Non-Governmental Organisation, the Komodo Survival Programme, was formed early in 2007, requesting that the European Association of Zoos and Aquaria act as a supervisor of this Komodo dragon conservation project.
Field activities followed in August and September 2006 devoted to community awareness activities and patrolling of the Wae Wuul Reserve. Community awareness activities are vital for regular interaction with the members of the 8 villages living outside the reserve to show continuous commitment to conservation, to help minimise the levels of encroachment in Komodo dragon habitat and to explain the long term effects of intensive poaching on wildlife in the reserve. Lectures in the community awareness programme covered descriptions of the current status of the reserve and its wildlife, a review of policies against cultivation and exploitation of the reserve and an outline of the activities to promote conservation and monitoring. Soon after the community awareness programme, patrolling activities commenced, conducted solely by the villagers and representatives of the Indonesian Department of Forestry. These patrols took place on alternate days in September, along 5 patrolling paths. Throughout such patrols, the villagers recorded feral dogs, signs of hardwood cuttings, a fire along the reserve boundary, and goat and water buffalo herds within the reserve boundary. These results indicate a reduced human pressure compared to 2005, possibly indicating the effectiveness of patrolling activities in the last 2 years. The feral dogs still, however, pose a threat as they hunt deer, a prey species of the Komodo dragon.
It is hoped that once the Wae Wuul Protection Plan becomes established as a regular, annual initiative then such activities within the park boundaries will stop completely and Komodo dragon numbers will increase.
Peninjauan lapangan ke Pos Jaga Cagar Alam Wae Wuul January 17, 2008Posted by ekologi in Uncategorized.
Tags: biawak Komodo, cagar alam, komodo survival program, ksda ntt, perbaikan pos, pos jaga, wae wuul
add a comment
Peninjauan lapangan ke Pos Jaga Cagar Alam Wae Wuul
16 Desember 2007.
Anggota tim :
M Jeri Imansyah (KSP)
Suprihatna (KSDA NTT)
Albert Berelaku (KSDA NTT)
Yohannes (KSDA NTT)
Cosmas Pandu (KSDA NTT)
Perjalanan dimulai dari Labuan Bajo menuju pos jaga CA Wae Wuul melalui beberapa desa di sekitar kawasan CA Wae Wuul. Kegiatan ini dilakukan untuk meninjau kondisi pos jaga dan kondisi kawasan di sekitar pos jaga. Berikut beberapa temuan yang perlu dilaporkan dari hasil pengamatan di lapangan;
- Kondisi pos
Kondis pos jaga yang dibangun pada tahun 1996 sudah dalam keadaan rusak. Beberapa bagian pos sudah rusak parah dan perlu segera diperbaiki. Kerusakan tersebut adalah :
- Instalasi air seperti bak air sudah retak dan rusak parah, pipa banyak yang patah, bak sumber air terlalu pendek.
- Lantai retak-retak,
- Kamar mandi dan septiptank tidak berfungsi,
- Tidak terdapat ruag dapur,
- Plafon rusak parah,
- Instalasi listrik rusak parah,
- Ventilasi dan sirkulasi cahaya matahari kamar tidur tidak memadai,
- Rencana perbaikan
Beberapa hal perbaikan pos jaga yang menjadi prioritas adalah sebagai berikut;
- perbaikan instalasi air, termasuk perbaikan bak penampungan air dan menyediakan satu bak air atau saluran khusus untuk keperluan masyarakat sekitar pos jaga
- perbaikan lantai
- perbaikan dinding, termasuk pemindahan jendela dan perbaikan ventilasi
- perbaikan atap dan plafon
- perbaikan instalasi listrik
- penambahan teras
- penambahan dapur
- penambahan satu kamar tidur
- pemindahan kamar mandi
- perbaikan septiptank
- penambahan tanggul di belakang bangunan pos jaga
- Pelaksanaan perbaikan
Perbaikan pos jaga akan dilaksanakan dalam waktu dekat dengan mempertimbangkan kondisi cuaca (musim hujan) yang sangat mempengaruhi kondisi jalan (berlumpur dan licin) karena sangat mempengaruhi proses pengiriman bahan bangunan dan alat. Pelaksanaan kegiatan akan dikoordinasikan dengan BBKSDA NTT
QUICK REPORT : WAE WUUL NATURE RESERVE RANGER STATION VISITATION January 17, 2008Posted by ekologi in Uncategorized.
Tags: Komodo dragon, komodo survival program, ranger station, renovation, wae wuul
add a comment
WAE WUUL NATURE RESERVE RANGER STATION VISITATION
In regard of Collaboration preparation between Komodo Survival Program and the Balai Besar Konservasi Sumber Daya Alam NTT.
A field trip to visit Wae Wuul Nature Reserve was conducted on December 16th, 2007, as part of our partnership with KSDA NTT to implement capacity building and conservation project of Komodo dragon and it’s environment on Flores. From the field trip, we identified several key findings that are important to implement.
- Renovation of Ranger Station.
Current ranger station is urgently to renovate as it is important to provide a more suitable condition for the rangers, volunteers, researchers, and stakeholders to utilize the station as basecamp of conservation works in WWNR.
- Reconstruction of zonation.
Most of the border marks (Pal, In Bahasa Indonesia) are missing. Thus the border in which separating nature reserve area and private land is unclear. This situation is could potentially causing a conflict between WWNR authority and local communities around the reserve area.
- Developing biodiversity and key species data base.
To date, no scientific information on biodiversity potential of WWNR is available as basic for the reserve authority to design and implement appropriate conservation and management strategies. Thus biodiversity assessment and documentation as well as developing data base are necessary to undertake.
- Developing specific study, monitoring and conservation strategies of Komodo dragon including the habitat.
Considering the habitat of Wae Wuul, a specific monitoring and conservation strategies of Komodo dragon and other key species, including the habitat should be considered to design. This requires a comprehensive assessment of potential and threats. Broad scale involvement of various stakeholders is necessary.
- Capacity building.
To enhance capacity and human resource skill of KSDA NTT staff in managing Komodo dragon and other key biodiversity in WWNR, capacity building activities, i.e trainings should be implemented. Specific trainings should be carried out base on the needs and priority that important to the management in WWNR.
Tags: human interaction, Komodo dragon, local community, tourist
GUIDELINE FOR THE MANAGEMENT OF KOMODO DRAGON-HUMAN INTERACTION WITHIN CONCESSION AREA
Komodo National Park was established in 1980 to ensure the long-terms survival of Komodo dragon (Varanus komodoensis), the largest living lizard in the world and the quality of its habitat (Erdman, 2004). Komodo dragon is protected species under Indonesian government regulation No. 8 1999 (Indonesia.1999). It is also listed in appendix I CITES, classified as vulnerable by IUCN (World Conservation Monitoring Center, 1996). Recently, the endangered status of Komodo dragons has been proposed to be updated following the reduction on populations, distribution and the evidence of population fragmentations (Ciofi & de Boer 2004).
Human activities within Komodo National Park has been existing before Komodo National Park established; even it is might be limited to human and wildlife interaction on local community such as nature resource harvesting (including terrestrial fruits and marine life). Apart from local community, human activities in tourism sector increased after Komodo National Park established, although UNESCO reported the statistical number of visitor showed steady decrease since 1997 to 2001 (from 29,842 to 12,612 respectively). With approximately 3000 people living in the park (located in Komodo Island, Rinca Island and Papagaran Island) (Erdman 2004) and a numbers of tourist visit Komodo National Park, it is important for management authority to manage human activities wisely along with wildlife (especially Komodo dragon and its habitat) in regard to create sustainable profitable human activities within the park including tourisms.
Due to the occurrence of interaction between human and Komodo dragon, therefore, the management authority will require a guideline for managing sort of interaction. A guideline on how human and wildlife could interact for sustainability of live hood with survival of wildlife is necessary to be developed. The guideline is including certain procedures that can be implemented by park authority within Komodo National Park.
Identification of Issues
1. How to reduce human impact on Komodo dragon and other wildlife
Wild animals are sensitive to variety of human activities, such as Bald Eagles are sensitive to visibility and noise levels (U.S. Fish and Wildlife Service 2007). The impact of human activities on Komodo dragon has documented by Lilley in Monk et al (2000), especially feeding attraction for tourist that change the natural behavior of Komodo dragons for hunting their preys. Another evidence were reported by Purwandana (2007) where nesting female avoiding human that approach to their nest.
2. How to increasing presence of Komodo dragons and others wildlife as tourism attraction.
In contrary, within tourism area, there are evidences of Komodo dragons difficult to find by tourist especially during mating season. There are several actions needed to solve the problems on managing the Komodo dragons along the tourism path.
3. How to reduce Komodo dragon’s impact on humans
The park authority should prevent the probability of wild life attack on human (villagers and tourists). The occurrences of Komodo dragon attack people (villager and tourist) should be consider as references on managing this animals when interact with people.
Several management actions are required to be implemented by park authority in order to address the issues;
1. Alternative jungle tracking / tourist paths.
à Alternative tourist path are necessary to established as substitute to the existing paths that crossing or near Komodo dragon’s nests is essential to construct and utilize during nesting season to reduce disturbance to females.
2. Limit number of visitors in a group
To reduce human impact on Komodo dragons:
à Limit the maximum number of people in a tracking group (We recommend not more than 10 people). The aim of this action is to minimize impact of visitors disturbing Komodo dragons and other wildlife.
à The gap between groups should be hold for 10 (ten) minutes each. This should be followed by sufficient number of guides. Maintaining gaps between groups will reduce the impact of human on wildlife, by minimizing contact between wildlife (especially Komodo dragons) and human. Funds should be provided for radio tranceivers to be allocated to rangers during guiding tours, in order for them to communicate with the sentry post and coordinate walking paces with preceding or following tourist groups.
à For specific flora or fauna observation interest, such as birdwatching, activities, it is more comfortable a group consist of maximum 3 people.
3. Establish observation platform or tower.
à This kind of action should be taken in order to reducing impact of human activities to active Komodo dragons nest or Megapode bird nest. The observation platform/tower could be permanently far from nest location (Jessop et al. 2004 has identified almost all nest location in Komodo Island). Another option is the alternative paths during nesting activities (Komodo dragons and Megapode bird).
4. Waste Management
Waste management should eliminate the attractiveness of Komodo dragon and other animals disturbing rubbish, and change the animal’s behavior to stay around the camp.
à Plastics material should not left in the islands. Plastics bags (from food) could eat by Komodo dragons and damage their digestive system.
à Rubbish from food (chicken/fish bones) should left from bungalows, ranger’s kitchens, and restaurant because Komodo dragons may still hang around the camp and change their natural behavior such as hunting. However, this is not immediately change the behavior of Komodo dragons around the camp, as the present situation has been going on for long time ago (more than 10 years).
5. Terrestrial Monitoring and Surveillance.
à Terrestrial monitoring and surveillance should focus on how to reduce number of illegal poaching (especially for deer) and illegal logging. Partially in Loh Liang, Illegal deer poaching might not occurred. However, evidence of illegal logging (including harvesting Tamarind and Srikaya fruit) in Loh Loh liang are frequently happened by villagers. Consider Loh Liang as tourism area, totally eliminate villagers activities are important. As the result, compensation area should be provided (Loh Kubu and Loh Bube)
6. Hanging bait
à Hanging bait might be performed in order to increase number of Komodo dragons sighting. However, this have to be wisely execute in order to eliminate behavior changes, therefore the Komodo dragon still hunt their preys. This can be done such as in random place and random time (once every month) along tourist paths
7. Establish and maintain artificial waterponds
à To increase wildlife sighting, rearrange artificial waterponds might become a consideration. This was demonstrated by Smit et al. (2007) on ungulates distributions in Africa are affected by location of artificial waterhole. Artificial waterhole may include next to the nest to increase probability of nesting females get enough food for body recovery.
à Certain education should conducted by park to villagers, people from Flores and Sumbawa mainland, including tourist. The material of education should encourage people to be wisely interact with wildlife, safety information when visit park, educate people to responsible of their own rubbish.
Tags: avifauna, bird, cockatoo, deer, habitat, Komodo dragon, mark-recapture, megapodius, Monitoring guideline, nest, reptiles, terrestrial, transect, wildlife
add a comment
In archipelagoes such as Indonesia, a nation with extraordinary high levels of biodiversity and endimicity, and where human perturbation is not uncommon, even within protected areas, overcoming the intrinsic biogeographic variation of managing such biodiversity is likely to be another challenge for conservation efforts. Komodo National Park (KNP) is a world heritage site, this area has a high biodiversity of tropical marine and the only potential habitat of giant endemic reptile Komodo dragon (Varanus komodoensis). Like most of National Parks in Indonesia, wildlife management in KNP restrain by less of reliable monitoring data base, because of limited source of fund, logistic, and local staff capability (Jessop et al., 2004). This guideline provides methods which technically can be adopted and used by KNP management to collect high accuracy and reliable database.
The major outcomes of this guideline are to increase knowledge of differences among island within
KNP with respect to prey availability and its influence on the demographic features of Komodo dragon populations. Second, collection of the appropriate life-history information that can be used to build specific population models that could assist in the management and conservation of key terrestrial species within KNP. Third, increasing the capacity of staff from KNP to effectively monitor wildlife populations within the park.
Specific Aims to research:
1. Life history and demographic differences in Komodo dragon populations across 4 islands within KNP.
Mark-Recapture studies should be used to assess demographic variation among island populations with respect to the following demographic parameters:
a) Population abundance of Komodo dragons at 10 study sites across four islands.
b) Age specific growth rates of Komodo dragons at 10 study sites.
c) Spatial ecology of Komodo dragons at 10 study sites
d) Assessing annual female reproductive rates across specific island sites
e) Hatchling production to assess variation in recruitment
f) Sex ratio.
Also recommend for further studies
f) Age specific survival rates of Komodo dragons at 10 study sites.
g) Parasitological (health and desease) of Komodo dragon
2. Prey density and diversity among four islands within Komodo National Park.
These monitoring activities will quantify temporal and spatial difference of large ungulate prey within Komodo National Park. Key criteria gathered from this monitoring include the following parameters. Knowledge of these parameters is essential for determining interactions between Komodo dragon and their prey.
a) Spatial and insular differences in density of Timor deer in KNP.
b) Spatial and insular differences in density of wild pigs in KNP.
c) Spatial and insular differences in density of water buffalo in KNP.
d) Spatial and insular differences in density of rats in KNP.
e) Spatial and insular differences in density of tokay geckos in KNP.
3. Assessment of habitat and other key and endangered species
a) Assessment of food resource (grass) availability
b) Active nest of Megapode birds
c) Active nest and direct population counting by vantage count for Cockatoo
d) Monitoring diversity of birds
e) Assessment the presence of exotic/invasive species
1. Life history and demographic differences in Komodo dragon populations across 4 islands within KNP.
Mark Recapture is a very effective method that most scientists implement to collect information on population ecology, age specific growth rates and spatial ecology (inter valley or inter islands migration) of Komodo dragon. Radio telemetry method is applied to assess more detail spatial ecology, i.e. movement pattern, home range, and behavior. Nest survey method that implemented transect grids method is very useful to assess annual female reproductive rates. Nest fencing method also useful to assess variation in recruitment by counting hatchling production from active nests.
Komodo dragons are captured by baited trap, noose or by hand. These methods are extremely effective for capturing all size classes of monitor above yearlings, which are largely arboreal. This trapping technique requires a 300 cm x 50 cm x 50 cm long box traps baited with goat meat (≈ 0.5 kg). Distance between traps is recommended between 200 m and 700 m from each other, depending on topographical and vegetation. Traps are positioned in shaded areas in order to avoid overheating of trapped individuals and are checked twice daily.
Following capture, Komodo dragons are restrained with rope and their mouths taped shut. Several morphological characters, including head length, and snout to vent length (SVL) are measured using calipers and a fiberglass tape. Body mass is obtained using digital scales. Komodo dragons are permanently identified using passive integrated transponders (i.e. PIT tags- Trovan ID100) inserted in to their left hind leg.
Mark recapture data then are entered into a central data base (Excel) and then transferred to demographic programs including MARK which will enable estimation of key demographic processes including population growth.
Radio telemetry is applied to assess a fine scale spatial ecology, especially to determine movement pattern and home range of Komodo dragon. This method requires transmitters, receivers, and antennas to be able to locate monitored animals. Transmitters are attached to selected animals either by harness, duct taped, or glued to the base of tail as it is considered the best site for placement. Attaching transmitters on juveniles by means of a harness was not feasible, thus use of duct tape or glue are consider the most feasible. Individuals are located either by direct observation or triangulation techniques (White & Garrot 1990). During tracking, certain parameters for habitat type or tree visited by animals recorded as follows; habitat type, tree species, breast height diameter, and tree height. Data will be calculated by means of a computer program ESRI ArcView 3.2 (ESRI 1999) with X-Tolls and Animal Movement program (Hooge et al. 2003).
Nest surveys by implementing transect grids
Field method implemented to inventory Komodo dragon nesting sites is consisted of intensive focal sampling across consecutive transect grids. This method involved multiple observers (5–8) walking at intervals of approximately 25 m apart along a series of parallel transects marked with projected GPS way points. The length and number of transects in each valley was defined by the prevailing topography of the valley. The purpose of these comprehensive transects was to identify and mark (with GPS point) all potential Komodo nesting sites and all megapode nests within each valley up to an elevation of 100 m above sea level. Once all nest are located, following annual monitoring are not require another intensive focal sampling, enough by checking the status of all marked nests and identify whether it is active or not.
Komodo dragons are known to use three types of nest and categorized as follows:
1) Ground nests- consisting of deep sloping horizontal burrows constructed in the ground.
2) Hill nests- typically consisting of large excavations resulting in one or more tiered platforms across the face of the hill. Into these excavations females would dig an egg chamber alongside a number of decoy chambers. These nests are situated in open savanna grassland which covers most low hillsides.
3) Mound nests- Komodo dragons utilized mound nests constructed by orange footed scrub fowl. Active Scrub-fowl mound nests are distinguished from active Komodo mound nests chiefly by the amount of debris and recent diggings that had occurred, particularly during August and September. This is fairly easy to determine as Orange-footed Scrub-fowl nest earlier in the year, with eggs recorded from January until April (Lincoln, 1974), plus megapode nests tend to incorporate vegetative debris into the mound and the chambers into which the birds oviposit (Frith, 1956; Jones et al., 1995).
Komodo dragon nests are identified by the presence of large chambers up to 2 meters long sloping into a nest. These nesting chambers are distinguished from resting chambers (Auffenberg, 1981) by the presence of multiple decoy chambers. Komodo dragon nests are confirmed active by the presence of recent digging activity by females (beginning in August) or by repeated observations of the female in association with the nest (August through November). Inactive Komodo dragon nests are confirmed by the absence of recent digging activity or female guarding the nest throughout the nesting season. These inactive nests are known to be used by Komodo dragons due to observations by park rangers (prior to the current season) of female digging and nest attendance activities or due to changes in structural characteristics, particularly the size and number of chambers in the nest. The density of active and inactive Komodo dragon nests is analyzed by dividing total nest number for each category by the area searched as calculated by shape polygons using Arc view 3.1 (ESRI). As an index of nest dispersion, the mean nearest neighbor measurement was calculated between valleys as the average distance to the closest neighbor from each active nest in a survey location.
Komodo dragon active nests monitoring should be undertook during early nesting season (August-September) each year. Monitored nests on Komodo and Rinca can refer to Jessop (2007) data.
Komodo dragon nests are confirmed active by the presence of recent digging activities by females (beginning in August) or by repeated observations of the female in association with the nest (August through November). Active Komodo nest will be guarded by associated female that laid her eggs in the nest for about 3-4 months (August-December). Once the female that guarding active nest is leaving, by late December, nest need to be fenced by 1,5 meter metal-sheeting plate. This fence is constructed to avoid emerged hatchling escapes before counted and measure, also to give protection to the hatchlings from being attacked by predators. Once nest-fence established, the nest should be checked twice daily. When hatchlings emerge from nest, all hatchlings are needed to capture, measure, and permanently marked. After all emerged hatchlings are released from the nest, to assess fecundity nest should be dug, to find and count the number of eggs and compared to number hatchlings that emerged.
Genetic and health studies
For further study, sex ratio and age specific survivorship of Komodo dragon by mean of genetic analysis and long term mark recapture method is highly recommended. Blood samples (300 µl) are collected from the caudal vein of new individuals (please refer to previous work of Jessop et al 2002-2006 of CRES ZSSD to identify marked and unmarked animals), using a 21 g needle and 3ml syringe, to enable further genetic sexing analysis of dragons. These blood samples should be stored and transported by staff of Balai Komodo National Park prior to further analysis at Genetic lab in Indonesia, i.e. LIPI.
Individual and population health of Komodo dragons is an important point that also necessary to monitor. Parasitological condition should be monitored by mean of fecal analysis and direct observation for thick that exists on the Komodo skin.
2. Prey density and diversity among four islands within Komodo National Park.
Assessment of density in large prey
Three species of large ungulate prey including the Timor deer (Cervus timorensis florensis), Wild pig (Sus scrofa) and Water buffalo (Babulus bubalus) are monitored by implementing indirect survey techniques (reviewed in Thompson et al. 1998) based on faecal counts: estimates from these techniques should be less influenced by the tendencies of prey to avoid people or be missed in forest. Counts of the standing crop of ungulate pellets or faecal pellet groups have been widely used to estimate the relative or absolute abundance of many ungulate species (Bennett et al., 1940; White, 1992; Thompson et al., 1998).
An indirect index of prey density is calculated using pellet counts on linear transects. Within each site between 20 and 49 permanent linier transects were randomly positioned and orientated (refer to Jessop 2007). Pellet groups are tallied from 30 sample plots placed across each 150 meter long transect. Each plot is a circle with a radius of 1 m and encompasses an area of 3.14 m2. All deer pellet groups within the plot were recorded. A group is standardized as a dense aggregation of pellets exceeding 40 pellets; groups below 40 are counted as individuals then divided by the mean pellet count (taken from counting 60 intact pellet groups). Pellet groups that are greater than 50% inside the plot area are counted as an entire group. To standardize seasonal differences, in pellet density it is important to conduct all pellet surveys across the 10 sites in late September and early October of 2006.
To calculate means bootstrapping technique is necessary to operate (Manly 1997), 95% confidence intervals (‘CI’) and CVs for the plot-based estimates of faeces abundance (per ha) for each large prey species at each site. Bootstrap estimates were based on 10 000 samples. The CV was:
Assessment of density in small prey
Rat (Rattus ratus)
Rats are captured by operating Elliot traps spaced at 10 meter intervals along randomly positioned trap-lines at each study site. Trap-lines placed with at least 200 m apart to reduce the possibility of animals being sampled by more than one trap-line. Trapped rats are individually identified, measured and released at the point of capture. Newly captured animals were given a unique mark by ear tagging. On their first capture during a trapping session animals are weighed and sexed. The head and body length is taken as being from the tip of the nose to the middle of cloaca, the tail length from the middle of cloaca to the tip of the tail. Tails with a terminal scar were assumed to be shortened and were excluded from measurement.
To assess differences in prey density among the five islands the plot counts, distance and mean number of rats per trap night should be undertook. The four sites on both Komodo and Rinca islands are pooled and used to infer a total island sample. Comparison of island means for each of the five species are analyzed by parametric and non-parametric analysis of variance depending on data meeting the assumptions of normality and homogeneity of sample variance. To discriminate significant differences among islands appropriate post- hoc methods (Tukey’s test and Dunn’s method) was used to identify subgroups.
Tokay Gecko (Gekko gecko)
Gekko gecko are monitored by using line transect technique. During the day prior to each survey mark out transect lines with fishing line marked for every five meters with flagging tape. All gecko surveys begin after dark, using powerful head-mounted 6V spotlights conducted by three people. Geckos counted by slowly walking along the transect line, searching every tree, shrub and vine mat within sight, on both sides of, and directly above the string. As often as possible walk off the transect line a few meters on either side; to give a wider range of viewing angles and the ability to more carefully search within trees directly above the transect line. When a gecko is sighted, measure the perpendicular distance at ground level directly beneath the gecko to the transect line (to within 0.1 m), and estimate the geckos height above ground to the nearest meter.
To estimate the density of geckos, use conventional Distance sampling method analysis. In this method the number of geckos located within the survey area are modelled as a function of perpendicular distance of the detected lizard from the line (Buckland et al. 2001). Data analysed using the program DISTANCE 4.2 release 1 (Buckland et al. 2001). DISTANCE is freeware available at http://www.ruwpa.st-and.ac.uk/distance/, and is widely used for the analysis of line transect data.
3. Assessment of habitat and other terrestrial key with focus on endangered species
Vegetations are monitored by plot method; permanent plots are placed in each represented habitat composition on each of 10 study sites. A 20×20 m permanent plot is established to estimate tree density with number of plots repetition depends on habitat size. Seedlings and saplings should be estimate by established subplots. Grass as the main food for herbivore animal is also monitored by using similar plot method. Density of grass is estimated by measuring 10 1×1 meter permanent plots in each of 10 study sites. Morphological characters like tree and grass species, DBH, height and canopy cover are measured by plastic measuring tape.
Active nest of Orange-footed Scrub-fowl (Megapodius reindwardt)
Orange-footed Scrub-fowl build conspicuous incubation mounds (Jones et al. 1995, Palmer et al. 2000). For each mound located, we recorded the location, elevation, status (active or inactive), overhead vegetation cover (0-25, 26-50, 51-75, or 76-100%), adjacent vegetation type (open forest, closed forest, savanna, or grasslands), and soil type (loamy, sandy, rocky, or gravelly). Inventoring incubation mounds is implemented by intensive focal samplings across consecutive transect grids with multiple observers (5 – 8) walking at 25-m intervals along parallel transects. The length and number of transects in each valley were determined by topography. Following annual monitoring will not require another intensive focal sampling, enough by check the status of all marked nest and identify whether its active or not. Structural characters of each mound are also need to recorded, including length, width, height, number of chambers excavated in each mound, and adjacent habitat type.
Active scrub-fowl mounds are those used for breeding during breeding season, and are distinguished from inactive mounds by evidence of recent digging, incorporation of new leaf litter, and, in some instances, the presence of adults at a nest or the presence of their tracks. Inactive mounds are those not being used in that breeding season and ranged from mounds with egg chambers containing old leaf litter to flattened mounds with no evidence of activity and covered in grass. The density of active Orange-footed Scrubfowl nests is calculated by dividing total nest number for each category by the area searched as calculated by shape polygons using Arcview 3.1 (ESRI). As an index of nest dispersion, the mean nearest neighbor measurement is calculated within valleys as the average distance to the closest neighbor from each nest in a survey location.
Due to the difficulty of measuring egg predation directly, we can use an index of predation based on the presence of fresh excavations into the egg chambers of active scrubfowl nests. Predators are identified by their tracks and associated burrowing as either Komodo dragons or wild pigs (Sus scrofa). Excavation by predators is likely to be repaired by scrubfowl, so observed excavations are likely made in the week preceding the survey.
Active nest and direct population counting by vantage count for Yellow-crested Cockatoo (Cacatua sulphurea)
Active nests survey
Nest survey is carried out by systematic searches (Mexquida, 2004) across consecutive transect grids, in which multiple observers (3-5 persons) walked at ≈ 25 meter intervals along parallel transects. The length and number of transects in each valley is defined by the prevailing topography of the valley. Nest searching is carried out across the valleys and including hills up to 60 meters elevation. Active nests are indicated by the present of young(s) in the nest and parents guarding the nesting location.
Once an active nest was located, data should be taken to record characteristics including location (GPS position), elevation, adjacent vegetation type (Open forest, closed forest, savanna), and nesting tree species. Structural characters of each nest are also recorded including tree DBH, tree height, and nest height. Nest locations are marked by means of GPS Garmin Etrex Vista (Garmin). Tree and nest height are measured by means of Suunto Clinometer (Suunto, Finland). To avoid disturbance to the occupants of the nests, nest parameters, i.e width, length, and depth, did not measured. To analyze the spatial distribution pattern, the nests were mapped and nearest neighbor-distances were calculated using the computer program of ArcView 3.1 (ESRI).
Population and Density Estimates
The Yellow-crested Cockatoo population estimate using direct counting of vantage point method in each valley (Bibby et al., 1992). Direct counting of vantage points method is carried out from hills, which provides observers a well suit observation points to observe the whole valleys and feasible to count all individuals sighted. To assess the density of this species within each valley, divide the highest number of the birds counted by the size of the valley. Sizes of the valleys are calculated by creating polygons, based on GPS points that collected during the field study, and covered the entire studied valley area on the map using the computer program of ArcView 3.2 (ESRI).
Monitoring diversity of birds
Inventory and monitoring of avifaunal diversity, can implement intensive focal sampling across permanent line transect. The length of each transect is 1 km, and number of transects in each valley are determined by topography and size of valley. Observer walking slowly across transect line, birds identified base on field guide. Duration of observation, number of observer must be recorded. Observation should be done minimum twice, early in the morning and afternoon (when the birds are most active).
Assessment the presence of exotic/invasive species
Field methods used to inventory presence of exotic/invasive species consisted of intensive focal sampling across consecutive transects grids. This method involved multiple observers (5–8) walking at intervals of approximately 25 m apart along a series of parallel transects marked with projected GPS way points, and then record all the exotic/invasive species (e.g. cactus, dogs, cats). The length and number of transects in each valley was defined by the prevailing topography of the valley. The purpose of these comprehensive transects was to try and identify all presence of exotic/invasive species within each valley. Once exotic species identified and located, further monitoring should be undertook on the same location. Further, elimination efforts should be consider preventing disturbances to the native wildlife and habitat in the Komodo National Park.
DRAFT: KOMODO DRAGON AND TERRESTRIAL WILDLIFE January 15, 2008Posted by ekologi in Uncategorized.
add a comment
We are now developing a Komodo dragon population management protocol that provided for the Komodo National Park authority. This draft is need to be further developed, therefore any suggestion are most welcome… to give comment or suggestion, please email us at firstname.lastname@example.org or email@example.com, or phone +62 361 7420434, or fax +62 361 710352.
KOMODO DRAGON (Varanus komodoensis) AND TERRESTRIAL WILDLIFE
A guideline is crucial to be developed as reference for the management of Komodo dragons, associated prey species, and their habitat. The guideline is provided for the management authority in response primarily to these following management issues:
· Declines in populations of Komodo dragons;
· Declines in populations of prey populations of Komodo dragons;
· Declines in habitat of Komodo dragons or their prey;
· Disturbances to Komodo dragons during mating;
· Disturbances to nesting females;
· Feeding of Komodo dragons – should this be allowed, and if so under what circumstances should it be allowed and what conditions?
· Creation of new ponds and the maintenance of existing ponds;
· Frequency of monitoring and management of data; and
· Translocation of dragons between islands and/or the mainland.
Current Status of Komodo dragons and affecting factors
Komodo dragon (Varanus komodoensis) is listed in the Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and classified as Vulnerable by the International Union for the Conservation of Nature and Natural Resources (IUCN 2000). The range of the Komodo dragon has decreased significantly over the last three decades due to several threatening processes including the suspected decline of large prey, such as Timor deer (Cervus timorensis) and anthropic habitat fragmentation and disturbances. Degradation of the environment is considered to be a major threatening process that could influence the viability of the extant dragon populations.
Density estimates of Komodo dragons were significantly different among four major islands in the Komodo National Park. Population density on Rinca (30.58 ind/km2) was significantly higher compared to the three other islands (18.82, 13.38, and 11.80 ind/km2 for islands of Komodo, Gili Motang and Nusa Kode respectively). Population abundance was varied among island with the highest was in Rinca (1046) and followed by Komodo (672), Gili Motang (127) and Nusa Kode (87) (Table 1). Dragon density estimates were significantly correlated to the density index of deer on each island. Insular population estimates of Nusa Kode and Gili Motang approximate or fall below several theoretical thresholds used to flag extinction proneness. Demographic stochasticity is usually the major component threatening population viability when the population size is in the order of 100 individuals or smaller.
Table 1. Density and abundance estimation of Komodo dragon in the Komodo National Park
* Obtained by measuring valleys that similar to study sites
** Results from extrapolation
REPRODUCTION AND ANNUAL RECRUITMENT
Komodo dragons displayed a declining trend in female nesting activities. In 2002, twenty seven (27) nests were recorded active, in subsequent years, the numbers declined to 22, 17, 17, and 7 in 2003, 2004, 2005, and 2006 (Figure 1a). Annually, 12 – 36 hatchlings are emerge from nests in February or March (averaged 19 hatchlings per nest per year) as new recruitment. Female’s reproduction related-activities was varied between months and showed a significant changes between July – September (Figure 1b). During the nesting activity, a female spend more energy to build and guard her nest and appears associated with a period of reduced feeding as females are observed to decrease weight (on average 3.42 kg). The interesting interval for females is variable, with only one female recorded nesting in 4 consecutive years, two females were active for two consecutive years; most females were recorded active only once. This suggests that most females are breeding less than annually.
SPATIAL MOVEMENTS AND ACTIVITY AREAS
Movement of hatchlings from their nests was largely linear consistent with natal dispersal. Rates of daily movement and size of activity areas in hatchlings were significantly less compared to juveniles (Table 2). However, habitat use in both classes of immature Komodo dragons was similar, both preferentially utilizing dry monsoon forest over other more xeric habitat types. During their early life stage hatchlings were predominantly arboreal compared to juveniles, and the degree of arboreal activity was strongly correlated with an individual’s size.
In adults, both female and male Komodo dragons displayed monthly variation in the daily movement and size of activity area (Figure 2). Nesting females exhibited nest-centered activities during the nesting period (August to December). Nesting females increased their rates of daily movement and size of activity areas after the third month. However, their core areas were not significantly different between months. Rates of daily movement in Adult male Komodo dragons varied among months. The highest movement rates were recorded in June, when the mating season begins and the lowest were in September, when the mating season ended and the females started nesting.
In general, rates of daily movement and activity areas in larger Komodo dragons were significantly larger compared to small dragons. Distance of movement and size of activity areas were significantly correlated with individual’s body size (Table 1). These distinct differences in spatial ecology suggest important changes in selection pressures operating on different size classes of Komodo dragons.
Table 2. Size, distance and size of activity areas of Komodo dragons.
ANNUAL PREY DENSITY
Annual density indices for large prey of Komodo dragons, Timor Deer (Cervus timorensis), indicated fluctuating trends over the last four years and potentially in decline. Overall prey density was correlated with island area with deer density on the larger islands of Komodo and Rinca been significantly higher than that of the smaller islands. The highest average density for deer was recorded on Komodo island (27.37), whilst the lowest was on Gili Motang (5.63).
- Biological and ecological constraint
As other reptiles, Komodo dragon has a very limited number of hatchlings that survive become adult as high mortality during the first age. Young Komodos are threatened by predation, cannibalism, and also extreme weather condition (e.g. hard-contiguous rain). Yet, survivorship of Komodo dragon is still unknown by scientist yet and require further study.
- Decreasing on reproduction rate
Declining in reproduction rate can be recognized by decrease in number of annual active nest and in turn reduce number of recruitment into population. This pattern is driven by Females are also known decreasing its body condition during nesting period and reduce its reproductive ability. The decreasing is correlated with the availability of deer as main prey of female Komodo dragons. Females require source of energy to recover and prepare them for nesting.
- Declining in key prey species population (Timor deer)
Deer population is also known correlated to the insular population of Komodo dragons body condition and population size. It is also believe that disappearance of resident Komodo dragons on Padar Island is stemmed from the decline of Timor deer (Cervus timorensis) populations due to illegal hunting. It was reported that there were at least 37.5 % cases of law violations in Komodo National Park between 2000-2001 was illegal deer poaching. Deer population also threatened by the existence of exotic species such as feral dogs, particularly on Rinca island.
- Grassland fires
There are number of forest fires incident happened within last decades. During 2002-2006 at least six grassland fires occurred within Komodo National park. The fires could affect the wildlife and habitat composition. Event though some grass or shrub species are fire-adapted and could contribute on regeneration of habitat, nevertheless major threats that from fires is not to the savanna but to the adjacent forested areas. Fires could degrade suitable habitat for Komodo dragons and its associated prey species. Fires could be deliberated by natural causes (extreme dry condition) and human (fires for poaching deer, extracting honey bee).
- Illegal logging
Villagers are extracting logs as their firewood, housing, carving and boat materials even though it is prohibited. There were several illegal logging cases, particularly in Loh Liang, Loh Lawi (Komodo island) and Gili Motang island, occurred between 2003-2006. Damages that caused by this activity, in turn, could risk Komodo dragon population. Trees are important for Komodo dragon as sleeping shelter and hiding place from predator for hatchling and juvenile, and provide shade during hot day. Trees also used as shelter by deer which mean can provide source of food for Komodo dragons.
- Unsustainable fruit harvesting
Villagers are harvesting tamarind fruit mostly in July and August. Uncontrolled harvesting activities can affect in reducing food resources for Timor deer population, and disturb arboreal Komodo dragons. Numerous people that involved during the harvesting process could also increase disturbance to the wildlife and habitat.
- Exotic species
Feral dogs are known existing in the wild, particularly on Rinca island and occasionally hunt for deer and suspected as one of young Komodo dragons predator or competitor for adult. During 2002-2004 cactus were found and spread in Loh Buaya. This exotic plan was so dominating and reduce suitable habitat for Komodo dragons. With a specific insect that could kill cactus, this exotic plan can be eliminated from Loh Buaya. Those are as example how exotic species can be a threat to terrestrial wildlife and particularly Komodo dragons.
- Lack of terrestrial and remote areas security system
Terrestrial and remote areas (Gili Motang) surveillance was not as frequent as marine surveillance. This lack could increase human disturbances that can increase risks of illegal wildlife poaching, habitat fires, illegal logging.
Proposed Management guidelines
To assist park authority, we propose several efforts that could be implemented in managing the extant population of Komodo dragon and its associated terrestrial wildlife and habitat. It is should be underlined that, to increase local community’s participation in protecting wildlife and habitat, involving villagers are important in every level of management activities.
1. Habitat protection and management
1.1. Prevention on forest fire and illegal logging;
à Educate local people to not to use fire next to either grassland or forest and increase their participation on fire extinguish incident.
à Educate local people to not extract live tree, and offer alternative of wood for their needs, i.e solar, gasoline, etc.
à Educate visitors to not to use fire along path or during their visit.
à Regular surveillance across terrestrial areas with particular land patrol on high risk spots and law enforcement.
à Train park rangers and villagers in fire fighting techniques and provide fire fighting equipment which should be kept ready at any time (backpacks, machetes, shovels, , face masks, personal equipments).
1.2. Manage fruit harvesting activities by villagers
à Managing occasion and specific areas that compensated for villagers to harvest fruits from the park. In Loh Liang, it is recommended to assign Loh Bube and Loh Kubu (Eastern Loh Liang) as traditionally areas for fruit, particularly tamarind, harvesting.
à Regular surveillance across terrestrial areas with particular land patrol on high risk spots.
à Educate villagers to harvest natural fruits form the wild within allocated areas for harvesting and by mean of sustainable harvesting techniques without causing any damages to habitat.
1.3. Monitor impact from tourism activity
à Tourism activity will affect on environment and its wildlife, including establishment of facilities. Impacts that caused by should be minimize and monitored to ensure that this activity minimize disturbance to both animal and plans.
à Educate visitors and guides to not disturb animals or plans during their activities.
à Study effective number and appropriate timing for tourist that allowed visiting into the wild. It is necessary to reduce disturbance to animal, especially during breeding season.
1.4. Habitat rehabilitation
à Habitat rehabilitation efforts should only be undertaken in severely damaged areas to recover their original condition. Only native species should be planted and, if possible, seedlings should be obtained from adjacent areas.
à Prior to any large scale rehabilitation, a pilot study should be undertaken to study the success level.
à It is also necessary to design the rehabilitation to mimic natural succession pattern and species association.
2. Wildlife management and monitoring
2.1. Intensive monitoring on terrestrial wildlife
à Intensive monitoring activities on terrestrial wildlife should be carried out with particular reference to study and monitor annual trends on Komodo dragon population, reproduction ecology, growth rate, prey availability (including large and small mammals, reptiles), and change of threat risks. This kind of monitoring should be undertook with yearly basis
à Intensive monitoring activities should be also highlight Gili Motang population, due to its remoteness, high risks of local extinction of Komodo dragon populations, and lack of management implementation in the past.
2.2. Restricted supplemental feeding strictly only for nesting female during nesting period to maintain its condition to prepare nest, lay eggs, guarding nest, and reproduce again on next breeding season;
à A very strict supplemental feeding may be given to only nesting female. This can be only given to nesting females which is in a very poor condition. Supplemental feeding can be only given once a month at the most located near nesting female in order to give energy for female to recover from its severe lack of nutrition during nesting period.
2.3. Intensive surveillance activities, with particular reference on the western part of Komodo and Rinca island and on the smaller islands of Gili Motang and Nusa Kode to prevent wildlife and habitat disturbances;
à Related surveillance activities, such as regular terrestrial and remote areas patrol, should be established and maintained to ensure security and prevention from illegal poaching, forest fires, and illegal logging. This activity can also be benefit in eliminating exotic animals, e.g feral dogs. Surveillance activities should be done with monthly basis.
2.4. Establish and maintain artificial water hole (ponds) within Komodo dragons “hot spot” and near nesting areas for females;
à Establishing artificial water ponds are necessary to attract and increase wildlife presence. Concentrated animal near ponds can be benefit as source of food (prey) for nesting Komodo dragons and tourist attraction.
2.5. Intensive control of pests and exotic species (e.g. feral dogs, cats).
à Exotic species should be controlled or even removed to reduce disturbance to native species by capturing or eliminating efforts.
2.6. Implementation of long term population monitoring
à Long term monitoring would ensure that managers have robust data to address population trends and decide which conservation options that the most appropriate. Population monitoring should be done with at least for every three years.
2.7. Regular monitoring program to observe further changes (decline or incline) of Komodo dragon’s population, prey species, predator, habitat, and environmental condition (climate);
à Regular monitoring on affecting factors to the Komodo dragon population is essential to anticipate any changes which effecting the population.
à Monitoring programs should be implemented in regular time basis and refer to monitoring guideline.
3. Human-wildlife interaction Management
3.1. Intensive monitoring to observe impact from ecotourism activities within tourism areas.
3.2. Limit number of tourism activities around active nests during nesting period
à Limit and arrange number of visitors and visiting time within concession areas.
3.3. Establish alternative tourist paths and observation stations
à Alternative tourist path are necessary to established as substitute to the existing paths that crossing or near Komodo dragon’s nests is essential to construct and utilize during nesting season to reduce disturbance to females;
à Establish observation stations, i.e. near Komodo dragon nest, would be useful to allow visitors in observing female’s activity during nesting period and to observe other wildlife and their interaction. It is also would be useful to reduce impact from human-wildlife interaction.
3.4. Improve tourist education to reduce perturbation to the habitat, including wild fauna and flora, particularly the Komodo dragon.
à Educate visitors to not disturb wildlife and habitat during their visit, including prevention from fires, rubbish management, and interact with Komodo dragons and other wildlife.
3.5. Increase local community participation in protecting habitat and wildlife
à Increase local community’s awareness to increase their responsibilities and participation in habitat and wildlife protection
à Provide alternative income to reduce disturbance on habitat from harvesting actitivies.
4. Species Translocation
Translocation might be needed to recover a severe declining population and as the last option and other conservation has failed. As translocation process may risks remaining population at targeted location, this option should be undertaken only as a measure of last resort as natural restocking. This option could be only chosen if indispensable to recover population declines.
4.1. Translocation of ungulate, i.e. Timor deer, to Gili Motang to increase prey availability for Komodo dragon on this island. This option should consider following issues prior to implementation:
à Develop a strict standard procedure of relocation as this option is strictly chosen as last alternative as other measurements are fail, including pre release and training facilities and procedure.
à Conduct detail habitat assessment, prey population capacity, existing Komodo dragon population and carrying capacity on release site.
à Ensure the individuals that are translocated have the most genetically and ecologically analogous and in a very health condition between source and targeted population.
à Develop a reliable monitoring and security system.
4.2. Translocation of Komodo dragon individuals from high density islands and/or Indonesian zoological gardens to low density islands(s) as reservoir for the long term maintenance of genetic variability and prevent local extinction. However this option should consider these following issues prior to implementation :
à Conduct detail habitat assessment, prey population capacity, existing Komodo dragon population and carrying capacity on release site.
à Ensure the individuals that are translocated have the most genetically and ecologically analogous and in a very health condition between source and targeted population.
à Develop a reliable monitoring and security system.
Further research / monitoring
There are numbers of research and monitoring should be carried out in the future to investigate several issues that contribute to the management of the extant population of Komodo dragon :
- Develop population models for Komodo dragon
- Investigate age-specific survivorship
- Investigate breeding participation rates of adult females
- Annual estimation on population demography
- Levels of Komodo dragon migration between islands
- Investigate annual trend on recruitment (number of clutches)
- Annual trend on nesting activity
- Annual trend on prey (ungulates, small reptiles, avian)
- Investigate competition between Komodo and other species, i.e wild boar.
Rain and Temperature dynamics on Komodo Island January 14, 2008Posted by ekologi in Uncategorized.
add a comment
2) Komodo National Park, Indonesia
3) Dept . of Animal Science, Univ. of Florence, Italy
4) Center for Conservation and Research on Endangered Species, USA
* Contact : firstname.lastname@example.org
RESULTS> There is a difference on rainfall pattern between the top of Mount Ara and coastal of Loh Liang valley. On Mount Ara, rain fall mostly between December to April with the highest in April (203mm). In Loh Liang, rain fall mostly between January to May, with the highest in April (236mm). During 2006 rain fall on Mount Ara was 689 mm while in Loh Liang was 637 mm.
> Mount Ara was cooler than Loh Liang valley with daily average temperature on Mount Ara was ranged from 19°C to 23°C, compared to Loh Liang valley which ranged from 23°C to 30°C. Daily average temperature on Mount Ara was also less fluctuated than that in Loh Liang valley.
> During 2004-2006, annual temperature dynamic in Loh Liang valley showed a similar pattern, with the highest in November and the lowest in August. In general, 2006 daily average temperature was lower than previous years.
> The highest temperature in Loh Liang valley was 36.6oC on November 2006 during midday and the lowest was 15.6oC on August 2006 in the morning. Daily temperature dynamic inside Komodo dragon’s nests in Loh Liang Valley was higher than that in the environment (outside nest) temperature. Hill nest has wider temperature range (27°- 32°C) and less fluctuated compared to ground nest (28° – 31°C).
We acknowledged Tim Jessop (CRES USA / Victoria Zoos Australia) and KNP staff who has helped us during the study, especially for Matheus Ndawapunga, Alo Sahu, Ayat, and Tresna. This study was conducted with support from the Zoological Society of San Diego, American Association of Zoos and Aquariums, and the European Association of Zoos and Aquaria. Approval for research was conducted under a MoU between the Zoological Society of San Diego and The Nature Conservancy (Indonesia Program) and the Indonesian Department of Forest Protection and Nature Conservation (PHKA).
Island specific conservation strategies January 14, 2008Posted by ekologi in Uncategorized.
add a comment
(Abstract presented in the International Seminar of Biology, Gadjah Mada University, Yogyakarta Indonesia, 7-8 September 2007)
Insular species are mostly susceptible to threatening processes due to limiting environmental factors including habitat loss, harvesting and invasive species because they are isolated and occur on smaller land masses (Burkey, 1995). Komodo dragon (Varanus komodoensis) is an endemic and vulnerable species inhabiting five islands in the Lesser Sunda region, southeastIndonesia. To facilitate implementation of management and conservation strategiesfor Komodo dragons in Komodo National Park, we identified insular differences among four major island populations by examining 1) Komodo dragon population density, 2) Komodo dragon body size, and 3) density of prey species (the Timor deer Cervus timorensis).
MATERIALS AND METHODS
The study was undertaken from 2003 to 2006 across 10 study sites on the islands of Komodo (393.4 km2), Rinca (278.0 km2), Gili Motang (10.3 km2), and Nusa Kode (9.3 km2) within the boundary of Komodo National Park. Capture-mark-recapture techniques were implemented to estimate differences in population density and body size among island Komodo dragon populations. Indices of Timor deer density, the main prey of Komodo dragons, was estimated by implementing pellet group density counts along line transects.
RESULTS AND DISCUSSION
The study showed significant insular divergences in Komodo dragon population density, body size for both SVL and weight, and Timor deer density as its main prey (One way ANOVA F3,3=120.67, p<0.001;>F3,99=10960.97, p<0.001) name=”OLE_LINK4″>F3,99= 6707.63, p<0.001), style=”color: black;”>F3,1218=120.67, p<0.001, respectively) (Table 1). Smaller islands showed significantly lower values of these parameters than the larger islands. Timor deer density index was showed significant correlation with Komodo dragon population density (R2=0.635, F2,202=191.74, P<0.001)>2=0.80, F2,96=191.74, P<0.001) and weight (R2=0.73, F2,96=131.05, P<0.001).
The study suggests that there are major divergences in both population (density and body size) and ecological parameter (main prey density) among insular Komodo dragon populations. In particular, the Komodo dragon population on Gili Motang island displayed significant differences in both population size and individual body mass from the other islands. Ciofi & Bruford (1999) showed that the Gili Motang population had the lowest level of genetic diversity compared to other insular populations as a result of limited gene flow and high genetic drift. Low population density, a reduced degree of genetic variation and a shortage of main prey species demand for island-specific conservation strategies for Komodo dragons on Gili Motang. Current management strategies adopted by Komodo National Park authority do not include the Gili Motang Komodo dragon population within the park conservation priorities.. Therefore, management officials should consider design of island specific conservation strategy of Komodo dragon populations in Komodo National Park, particularly for small islands such as Gili Motang.
Table 1. Summary results of Komodo density, body size, and prey density index
||Komodo Density (ind/km2)
||Komodo SVL (cm)
||Komodo weight (kg)
||Deer density (pellet group/ transect)
Figure 1. Correlation between Deer density index and Komodo density
 Burkey, T.V., “Extinction rates in archipelagos: implications for populations in fragmented habitats”, Conservation Biology 9, 527–541. 1995.
 Ciofi, C., Bruford, M.W., ”Genetic structure and gene flow among Komodo dragon populations inferred by microsatellite loci analysis”, Molecular Ecology 8, S17–S30.1999.
 Jessop, T.S., Madsen, T., Ciofi, C., Imansyah, M.J., Purwandana, D., Rudiharto, H., Arifiandy, A., Phillips, J.A, “Island differences in population size structure and catch per unit effort and their conservation implications for Komodo dragons”, Biological Conservation 135:247-255. 2007.
Komodo eating Turtle January 14, 2008Posted by ekologi in Uncategorized.
Tags: carnivore, green seaturtle, Komodo dragon, komodo preys, nature predation
add a comment
It is well known that Komodo dragon is a carnivore and scavenger. Komodos main prey item is Timor deer (Cervus timorensis), however, this giant lizard is able to feed on various things such as buffalo, lizards, snakes, avians, small mammals (rats), and fishes (Auffenberg, 1981). Auffenberg (1981) also noted that Hawksbil sea turtle (Eretmochelys imbricata) and its eggs is one of Komodos prey among reptiles as their food.
A recent documentary (Aug 17th, 2007) showed three adult Komodo dragons are eating on a young Hawksbill sea turtle. This video is taken in Loh Liang, Komodo island, the biggest island within Komodo National Park.
Video showing adults Komodo dragon eating sea turtle
(sorry due to technical problem, the video can not be shown)
Komodo pulau kecil rentan punah January 14, 2008Posted by ekologi in Uncategorized.
Tags: ancaman kepunahan, biawak Komodo, pulau kecil
1 comment so far
Biawak Komodo di pulau kecil lebih rentan untuk punah.
Sebagian dari hasil proyek konservasi dan penelitian biawak Komodo di Balai Taman Nasional Komodo oleh CRES dan BTNK.
Dimuat di Warta Herpetofauna Indonesia Agustus 2007 sebagai artikel
Tim S Jessop, Claudio Ciofi, M Jeri Imansyah, Deni Purwandana, Achmad Ariefiandy, Heru Rudiharto
Biawak Komodo (Varanus komodoensis Ouwen) adalah biawak terbesar di dunia (King & Green, 1999), namun sebarannya sangatlah terbatas dan hanya dapat ditemukan di lima pulau di daerah Tenggara Indonesia (Ciofi & de Boer, 2004). Selain Flores, pulau terbesar dalam cakupan wilayah sebaran biawak Komodo, empat pulau lainnya, yaitu Komodo (393.4 km2), Rinca (278.0 km2), Gili Motang (10.3 km2), dan Nusa Kode (9.3 km2), termasuk dalam wilayah pengelolaan Balai Taman Nasional Komodo (Jessop dkk., 2007a; PHKA, 2000). Bobot biawak Komodo dewasa dalam keadaan normal dapat mencapai 81.5 kg dan panjang tubuh keseluruhan dari moncong hingga ujung ekor mencapai 305 cm (Jessop dkk. unpublished data). Makanan utama Komodo dewasa adalah mamalia besar seperti Rusa Timor (Cervus timorensis), Kerbau (Bubalis bubalus) dan Babi (Sus scrofa), dengan mengandalkan strategi penyergapan dalam memburu mangsanya, sedangkan Komodo anak lebih aktif mencari untuk mendapatkan mangsanya seperti tokek pohon (Gekko gecko), telur Ayam hutan (Gallus gallus), ular, dan tikus (Auffenberg, 1981).
Ketergantungan yang cukup tinggi akan rusa sebagai makanan utamanya (>40%, Auffenberg, 1981) menyebabkan Komodo sangat rentan terhadap perubahan yang terjadi pada populasi rusa di wilayah sebaran Komodo (Ciofi & de Boer, 2004; Jessop dkk., 2006). Indeks tahunan kepadatan spesies mangsa besar untuk biawak Komodo, Rusa Timor (Cervus timorensis) mengindikasikan kecenderungan penurunan selama kurun tahun 2003-2006 (Gambar 1a). Kepadatan rusa diketahui berkaitan secara positif dengan luasan pulau, di mana pulau besar, Komodo dan Rinca, secara signifikan lebih tinggi dari pada kepadatan di pulau kecil, Nusa Kode dan Gili Motang. Indeks kepadatan rusa tertinggi tercatat di pulau Komodo, sedangkan terendah di Gili Motang (Gambar 1a; Jessop dkk., 2007a).
Tabel 1. Kepadatan Komodo tiap pulau di TNK
Ukuran pulau (km2)
Gambar 1. Grafik fluktuasi indeks kepadatan tahunan rusa (a) dan korelasi kepadatan Komodo dengan indeks kepadatan rusa (b).
Kepadatan Komodo saat ini diketahui pada tingkat rata-rata di bawah 20 individu per km2 tiap pulaunya (Tabel 1). Secara keseluruhan, kepadatan populasi pulau tertinggi terdapat di pulau Rinca (30,58 individu/km2), sedangkan kepadatan terendah terdapat di Nusa Kode (11,80 individu/km2) (Jessop dkk. 2007a). Kepadatan biawak Komodo secara signifikan berkorelasi dengan indeks kepadatan rusa sebagai mangsa utamanya. Sebagai mangsa utama bagi komodo, kondisi populasi rusa merupakan komponen kunci yang sangat berpengaruh terhadap kondisi populasi komodo, baik secara fenotif, maupun tingkah laku (Jessop dkk., 2007b). Seiring dengan kondisi kepadatan Komodo tiap pulau yang berkorelasi dengan ukuran pulau, ukuran tubuh dan tingkah laku biawak Komodo pun nampaknya berkorelasi pula dengan ukuran pulau. Komodo di pulau besar cenderung memiliki ukuran tubuh besar dan memiliki agresivitas yang lebih tinggi, sedangkan Komodo di pulau kecil, yang memiliki ukuran tubuh relatif lebih kecil dan lebih waspada terhadap kemungkinan pemangsaan, dalam hal ini kanibalisme oleh Komodo yang lebih besar (Jessop dkk., 2007b).
Dari keseluruhan populasi pulau biawak Komodo di TNK, nampaknya populasi di Pulau Komodo dan pulau Rinca berada dalam kondisi aman, sedangkan populasi di pulau kecil Gili Motang dan Nusa Kode menunjukkan gejala berada dalam kondisi ancaman kepunahan yang lebih tinggi dari pada populasi pulau lainnya (Jessop dkk., 2007a). Hal ini terutama ditunjukkan dengan rendahnya kepadatan populasi biawak Komodo (>15 individu/km2), juga disertai dengan rendahnya nilai indeks kepadatan rusa sebagai mangsa utama (> 10). Perbedaan jenis dan ketersediaan mangsa antar pulau, serta kompetisi intraspesifik diketahui secara jelas menjadi faktor seleksi penentu perubahan populasi dan pembentukan struktur komunitas, dan akhirnya survival spesies, dalam habitat kepulauan (Grant, 1998). Perbedaan tingkah laku kewaspadaan antar populasi pulau dapat juga mencerminkan peningkatan tekanan predasi intraspesifik (Cooper 2003; Heithaus dkk. 2002; Stone dkk. 1994). Hal ini nampak dari respon biawak Komodo di Gili Motang dan Nusa Kode yang lebih sering menghindari kehadiran manusia dari pada populasi di pulau Komodo dan Rinca (Jessop dkk., 2007c).
Dari sudut pandang manajemen, perbedaan berbagai aspek biologi dan ekologi Komodo antar pulau dapat menggambarkan adanya kebutuhan untuk mengembangankan rencana spefisik pulau yang disesuaikan dengan kondisi populasi (Jessop dkk., 2007c). Hal ini terutama penting sehubungan dengan informasi demografis jangka panjang mengenai perbedaan kondisi populasi pulau di TN Komodo, dan awal gangguan terhadap populasi-populasi ini di mana penyebaran dan imigrasi dibatasi oleh halangan lautan (Whittaker, 1998).
Daftar Pustaka / References:
Auffenberg, W. 1981. The Behavioral Ecology of the Komodo Monitor. Gainesville : University of Florida Press.
Ciofi, C. & de Boer, M.E. 2004. Distribution and conservation of the Komodo Monitor (Varanus komodoensis). Herpetological Journal 14: 99-107.
Cooper, W. E. Jr. 2003. Effect of risk on aspects of escape behavior by a lizard, Holbrookia propinqua, in relation to optimal escape theory. Ethology 109, 617-626.
Grant, P.R., 1998. Evolution on Islands. Oxford University Press, UK.
Heithaus, M. R., Frid, A. & Dill, L. M. 2002. Shark-inflicted injury frequencies, escape ability and habitat use of green and loggerhead turtles. Mar. Biol. 140, 229–236.
Jessop dkk. 2007a. Ekologi populasi, reproduksi, dan spasial biawak Komodo (Varanus komodoensis) di Taman Nasional Komodo. Disunting oleh Imansyah, M.J., Ariefiandy, A. dan Purwandana, D. BTNK/CRES-ZSSD/TNC.
Jessop, TS., Madsen T., Ciofi, C., Imansyah, M.J., Purwandana, D., Ariefiandy, A., Phillips, J.A. 2007b. Biawak Komodo plastis: respon predator besar terhadap pulau kecil. Terjemahan. Ariefiandy, A., Purwandana, D., Imansyah, M.J. CRES-ZSSD/BTNK/TNC. Labuan Bajo, Flores, Indonesia.
Jessop, T.S., Madsen, T., Ciofi, C., Imansyah, M.J., Purwandana, D., Rudiharto, H., Arifiandy, A., Phillips, J.A. 2007c. Island differences in population size structure and catch per unit effort and their conservation implications for Komodo dragons. Biological Conservation 135:247-255.
Jessop, T. S., Madsen, T., Sumner, J., Rudiharto, H., Phillips, J. A. and Ciofi, C. 2006. Maximum body size among insular Komodo dragon populations covaries with large prey density. _/ Oikos 112: 422_/429.
King, D.R. & Green, B. 1999. Goannas: the biology of Varanid lizards. Sydney: New South Wales Press Ltd.
PHKA. 2000. 25 years master plan for management Komodo National Park, Book 2: data and analysis. Jakarta: PHKA, The Nature Conservancy, Manggarai District Authority.
Stone, P. A., Snell, H. L. & Snell, H. M. 1994. Behavioral Diversity as Biological Diversity: Introduced Cats and Lava Lizard Wariness. Cons.Biol.8,569-573.
Whittaker, R. J. 1998. Island Biogeography: Ecology, Evolution and Conservation. Oxford: Oxford Univ. Press.
Tim S Jessop1,2, Claudio Ciofi3, M Jeri Imansyah1,4*, Deni Purwandana1,4, Achmad Ariefiandy1,4, Heru Rudiharto5
1) Center for Conservation and Research of Endangered Species; the Zoological Society of San Diego; San Pasqual Valley road, Escondido, CA. 92027-7000, USA.
2) Zoos Victoria; Elliot Avenue, Parkville, Melbourne, Victoria 3052, Australia.
3) Department of Genetic and Animal Science, University of Fiorentina, Florence, Italy
4) Balai Taman Nasional Komodo; Jl Kasimo, Labuan Bajo, Flores, Indonesia.
5) Komodo Species Survival Program Indonesia; Jl Sudirman IV, Gg Karya Bhakti II no 6, Denpasar 80232, Bali, Indonesia, ph 0361-7420434.
* Kontak: email@example.com