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PNGIBR PublicationsPNGIBR Staff and Student Honours and Masters Thesis AbstractsStaff & Student Publications | Relevant Board Publications
Gamui, B. 2005. Litter production and net primary productivity of a tropical montane forest in Papua New Guinea. Honours thesis, University of Papua New Guinea. ABSTRACT Forest Litter Production and Net Primary Productivity studies look at quantifying above ground biomass of forest plants. This is a correlate of the amount of carbon taken up by plants from the atmosphere for photosynthesis and incorporation into their living biomass. With the help of research assistants, I conducted over 12 months sampling of forest litterfall and looked for seasonality and production rates in the various litterfall components (leaves, flowers, fruits, twigs, moss, and others). To calculate above ground biomass and aboveground biomass increment, we measured trees ≥ 10 cm diameter at breast height on 20 permanent 50m x 50m vegetation plots covering a total of 5 hectares in 1998 and again in 2003. I then calculated the Net Primary Productivity for this forest, which is the sum of litterfall production and aboveground biomass increment. Litter Production in the Mekil lower montane forest is 5.59 Mg ha-1 y-1. Assuming dry mass is 50% carbon (Clark et al 2001), the forest produces 2.52 Mg C ha-1 yr-1 with a 95% confidence interval of 2.26 to 2.78. The forest is aseasonal, based on temperature and rainfall recorded. There was no seasonality in litterfall either, and leaves accounted for 61 % of litterfall, other debris for 15%, twigs ≤ 1 cm diameter for 13%, moss for 5%, fruits for 4%, and flowers for 2%. Based on the 5 hectare sample, in 1998 total above ground biomass was 196.8 Mg ha-1. In 2003 total estimated above ground biomass was 198.6 Mg ha-1. Using census and re-census data from these 5 ha over a 5.5-year census period, I measured aboveground biomass increment at 3.73 Mg ha-1 yr-1, or 1.87 Mg C ha-1 yr-1. At a time when Papua New Guinea and the world over, grapple for carbon sequestration credits and carbon trade opportunities, this study may give some insight into how much carbon a PNG forest may absorb with implications for carbon credits. Igag, P. 2003. Breeding biology and
reproductive success of three large Rain forest parrots; Palm cockatoo
Probosciger aterrimus, Vulturine’s parrot Psittrichas fulgidus and Eclectus
parrot Eclectus roratus in New Guinea. Masters thesis, Australian National
University. In this thesis I outline the breeding biology and likely causes of threat to three species of large parrot found in the New Guinea rainforest: palm cockatoos (Probosciger aterrimus), Pesquet's parrots (Psittrichus fulgidus), and eclectus parrots (Eclectus roratus). All species are threatened by loss of habitat. Palm cockatoos and Pesquet's parrots are further threatened by being hunted for food and the thriving trade in the latters' feathers. Eclectus parrots are more abundant and less threatened from hunting, and provide a good comparison with the two former species. I first describe the traditional people, how they use the resources of their land (including the parrots), and how attempts are being made to integrate conservation with their economic development. By training 23 traditional land-owners as assistants, I was able to monitor the breeding efforts and reproductive success at 51 palm cockatoo, 71 eclectus parrot and 34 Pesquet's parrot nest trees over 28 months at my 2645 ha study site. Some retrospective information was also attained from local people who knew about nest trees prior to the study. Only palm cockatoos and Pesquet's parrots showed any overlap in the species of trees they used for nesting. The hollows used by each of the three parrot species differed significantly in every quantitative physical characteristic I measured. Palm cockatoo hollows tended to be in the skywards-facing end of a broken, dead trunk. Pesquet's parrots were the only species to entirely excavate their own hollows; they used the trunks of dead trees, but their hollows had entrances that opened sideways. Eclectus parrot hollows were in taller, live trees and had entrance sites and angles that were more varied than the other two species. The density of palm cockatoo nest trees averaged 0.06 nest trees/ha, but the annual density of active nests was only 0.008/ha. The density of eclectus parrot nest hollows averaged 0.07/ha, but the density of active hollows each year was 0.023/ha. Pesquet's parrots excavated new nests each year and the annual density of these was 0.017 nests/ha. Eclectus parrots tended to nest closer to human settlements than either palm cockatoos or Pesquet's parrots. Palm cockatoos and Pesquet's parrots bred seasonally, with eggs being laid between June and October. In contrast, eclectus parrots occupied their nests and bred all year. In any one year one-sixth of all potential palm cockatoo nest trees were actually used for breeding, whereas eclectus parrot nests were active more than once per year on average. Similar figures for Pesquet's parrots were not available. Palm cockatoos always laid one egg, Pesquet's parrots laid one or two eggs, and eclectus parrots usually laid two eggs. Eclectus parrots were the most successful at fledging young - 54% of all eggs laid (in 66% of broods) resulted in a fledgling. This compares to 40% in palm cockatoos and 17% (in 20% of broods) in Pesquet's parrots. Whereas most losses in palm cockatoos and eclectus parrots were due to predation, Pesquet's parrots lost chicks (of all ages) through starvation. Data on chick growth, feeding rates, and preferred food types are also presented. I conclude that the major life-history traits that render palm cockatoos rare and vulnerable are their low density of nest trees and infrequent breeding, whereas Pesquet's parrots appear to be most affected by low breeding success. In contrast, frequent breeding attempts, relatively high breeding success, and relative immunity to human disturbance make eclectus parrots less rare and vulnerable. I suggest several recommendations to ensure the persistence of the three parrot species in the CMWMA in the short-term, and directions for future research to help secure their survival in the longer-term. Kale, E. 2008. Density, diversity
and reproductive patterns of small mammals in the Crater Mountain Wildlife
Management Area, Papua New Guinea. Honours thesis, University of Papua New
Guinea. Accurate assessment of density, diversity and reproductive patterns of tropical rainforest mammal species is important for management decisions such as determining sustainable harvest of game species. However, very few studies have been conducted in New Guinea, the world’s largest tropical island and home to hundreds of hunter-gatherer ethnic groups. To assess mammal density, diversity and reproductive patterns, I conducted a year-long mark-recapture trapping of small mammals in a 6.7 ha grid and an 850 m transect in an undisturbed rain forest at 900-1100 m elevation in the Crater Mountain Wildlife Management Area (CMWMA) in 2005. I trapped 407 individuals from three families and 12 species giving an alpha diversity of J' = 0.375. I captured 216 Stenomys verecundus; 92 Melomys platyops; 32 M. rufescens; 5 M. leucogaster; 44 Uromys caudimaculatus; 6 Dasyurus albopunctatus, and an individual each of Antechinus melanurus, Lorentzymys nouhuysi, Xenuromys barbatus, Echymipera kalubu, Myoictis melas and Phalanger gymnotis. Density estimates per hectare for the four most common species were; 43 S. verecundus, 17 M. platyops, 14 U. caudimaculatus and 7 M. rufescens. S. verecundus was the dominant species throughout the study. Breeding in S. verecundus is aseasonal and peaked from May through August. A female S. verecundus showed evidence of producing up to three litters a year. Long seasonal reproduction is observed in M. platyops from May to December. U. caudimaculatus appear to show the same pattern as in M. platyops with long breeding season observed from May to December. One U. caudimaculatus showed evidence of producing three litters per year. Breeding in M. rufescens is observed year-round indicating aseasonal reproduction. Females of M. rufescens are capable of carrying three litters per annum. Male biased sexual dimorphism was observed in S. verecundus and M. platyops while in M. rufescens, it is observed only in mass and head-body length but not in tail lengths. Sexual dimorphism was not observed in U. caudimaculatus. This is the first ever year-long study on small mammals in PNG and the data generated here can be used for sustainable management of game species in the CMWMA. Kigl, M. 2003. Riverine waste
disposal: Porgera mine sediment impact on the Porgera-Lagaip-Strickland river
systems. Honours thesis, University of Papua New Guinea. The abundance of high volume, fast flowing rivers, steep topography, and high rainfall year round would seem to favour direct disposal of mine tailings effluent and waste rock into the local rivers. Fine sediment particles added to the rivers are transported mostly in suspension and solution. The effect of sediment input varies depending upon sediment load, grain size, and river competency to adequately dispose of wastes discharged. Process chemicals and heavy metals discharged are also important environmental contaminants. The more ecologically harmful heavy metals, in both soluble and insoluble forms, are those that move freely within the water column than those that remain fixed to the sediment loads. River degradation and effects on local communities from such pollutants has attracted much controversy. Porgera’s triple bottom line approach is seen as a role model for ecologically sustainable mining. However, the project’s environmental management and monitoring program is criticized for not conducting impact assessments in addition to its compliance monitoring. The sustainable and healthy functioning of the river ecosystem has been compromised with increasing concentrations of sediments and process chemicals that exceed both pre-mine concentrations and compliance standards. Studies have indicated that extensive pollution of the entire river system has occurred. The company claims as baseless and unscientific other reported cases of adverse health and environmental impacts. The reports, however, have scientific credibility and remains to be addressed. Legra, L. 2005. Nest-site selection
and behavioural biology of the New Guinea Harpy Eagle, Harpyopsis novaeguineae.
Honours Thesis, University of PNG. Not much is known about the New Guinea Harpy Eagle (NGHE). So far only three studies have been done on the species. Two are short communications, one on temporal variation of the frequency of vocalizations and the other on attempts of the NGHE to capture a monitor lizard. The third study was conducted over a two-year period and was more in-depth covering hunting behaviour, calls, dispersion, and habitat use and conservation status of the NGHE. Though these studies have revealed some information much remains to be discovered. I visited six NGHE nest trees from October to December 2003 and February, April to June and September 2004 in order to observe juvenile NGHE behaviour and study their habitat selection. I found and tagged fifty- nine NGHE roost trees and measured the height, DBH, branch type, tree type, location, accessibility and local disturbance at both roost and nest trees. Roost trees averaged 28 m high (range 15-45m) and 67 cm DBH (range 23- 144 cm). NGHE nest trees were of greater DBH (t=4.21, P<0.05) and height (t=5.44, P<0.001) than random trees. NGHEs were selecting nest trees with relation to the type of tree (G=10.17, P<0.05), the bark characteristics (G=7.14, P<0.05), accessibility to the nest (G=7.82, P<0.05) and the level of disturbance at the nest site (G=22.13, P<0.05). At the macro scale, habitats of nest sites were largely forested, further away from the nearest human walking track and located further from the nearest source of water. I collected a total of 30 prey items from around nest and roost trees. NGHEs consumed mammals (70%), birds (23%) and reptiles (7 %). Calling activity of the NGHE was evenly distributed throughout the day. Nest site selection studies are important for the conservation of species and their habitats. Information from these studies could be used to help designate areas that are adequate and of importance to focal species. Novera, J. 2009. Seasonality and
subsistence hunting practices among the Sokamin people in Saundaun Province,
Papua New Guinea. Honours thesis, University of Papua New Guinea. In Papua New Guinea (PNG), wild animals play a significant role in the cultural and social life of indigenous people and are an important source of protein and nutrients. The Sokamin people in the Telefomin District of Sandaun Province depend almost entirely on subsistence hunting for protein. I studied hunting practices of the Sokamin people, collecting data on hunters, the species they hunted, and the ecological and socio-economic matrix in which they live. Daily rainfall data were recorded from 2002 to 2007. Monthly rainfall varied significantly among month showing distinct wet and dry periods. The hunters hunt all year round regardless of rainfall. I interviewed 107 hunters in the wet season (54 % male and 46 % female) and ninety-four hunters (55 % male and 45 % female) in the dry season. I collected 1199 prey items of which mammals constituted 66 %, birds 24 %, reptiles 8 %, and amphibians 2 %. There were significant differences in the prey killed by men and women. Males captured more mammals and birds than women. Women captured more reptiles and amphibians than men. Furthermore, bow and arrow is the main hunting method employed by male hunters. Hunters in larger settlements also captured more prey items compared to hunters in small settlements. This study addresses factors affecting the availability and distribution of game animals to hunters and will help us design proper management protocols for sustainable hunting practices in PNG. Opiang, M. 2005. A study of home
range, movement and den use in long-beaked echidnas, Zaglossus bartonii, in the
Crater Mountain Wildlife Management Area, Papua New Guinea. Honours
thesis, University of Papua New Guinea. Long-beaked echidnas (Zaglossus spp.) are critically endangered, yet no conservation management plan exists for them due to lack of data. I investigated home range, movement, and den usage by capturing twelve and radio-tracking six long-beaked echidnas (Z. bartonii) in the Crater Mountain Wildlife Management Area, Papua New Guinea between 2000 and 2003. I also trialed three transmitter attachment methods. Adult mean mass was 6.6 kg (SD = 1.5, n = 6) and juvenile mean mass was 4.4 kg (SD = 0.7, n = 6). There were positive correlations between body mass and head-body length, body mass and snout length, and head body length and snout length. I never found echidnas foraging in daylight and did not find animals with eggs or pouch young. However, I did find a long-beaked echidna lactating from April to May 2002. Yearly growth rates for two echidnas were 1.8 g and 0.6 g per day. I tracked echidnas for 0 to 80 days before transmitters either dislodged or failed. Of the three techniques trialed for attaching transmitters, I suggest anklet attachment as most appropriate for long-beaked echidnas. Estimated home range varied from 10 to 198 ha (mean = 87, SD = 78, n = 6), and daily den to den movements ranged from 15– 823 m (mean = 216, SD = 147, n = 52). Larger animals did not have larger home ranges than smaller animals, and adults did not have larger home ranges than juveniles. Dens were more common in low shrub density areas than in high shrub density areas. Mean burrow length was 2.7 m (SD = 1.8, n = 5, range = 1.3 - 4.9 m), mean den depth was 0.48 m below surface (SD = 7.8, n = 5, range = 0.42 - 0.57 m), and sleeping spots within burrows were usually at the end of the burrow and uphill from the burrow entrance. More den sites were underground than above ground. Adult echidnas tended to den in underground burrows more than juveniles, suggesting den type used was determined by experience. Animals were motionless when first dug out from dens but became active within two minutes. This suggests that if they do go into torpor, it is a shallow torpor. Sagata, K. 2003.
Colonization of twig-nests by forest litter ants in a Papua New Guinean wet
highland tropical forest. Honours thesis, University of Papua New Guinea. In Papua New Guinean rainforests the ecology of twig-dwelling ants is practically unknown despite their significance in ecological interactions such as recycling of nutrients. I investigated the colonization ability of twig-dwelling ants by establishing artificial nests in areas cleared of resident twigs and areas not cleared of resident twigs. I also collected ants from natural nests and leaf litter. Forty-one species of twig-dwelling ants were found in this study. Clearing resident twigs from the forest floor did not affect the tendency of ants to colonize artificial nests (χ2 = 1.67, df = 1, P>0.1), but artificial nests did have fewer ant species than leaf litter (K-S = 0.30, P>0.05, n1 & n2 = 40) or natural nests (K-S = 0.30, P>0.05, n1 & n2 = 40). Plots with higher densities of artificial nests did not have more nests colonized than plots with lower densities (χ2 = 6.44, df = 2, P<0.05). Furthermore, far fewer natural nests were colonized then were available. These results suggest that nest sites are not a limiting resource for twig-dwelling ants in the highlands of New Guinea. However, ants were spacing themselves in some order over the forest floor. Nest competition apparently cannot explain this. Therefore, research into competition for other resources and abiotic factors such as nest selection to avoid local disturbance may help us understand the processes responsible for affecting twig-dwelling ants and their colonization patterns. Sagata, K. 2007.
The influence of propagule size on incipient colony establishment of invasive
Argentine ant, Linepithema humile Mayr (Hymenoptera: Formicidae). Master
thesis, Victoria University of Wellington. Propagule size is an important factor in determining establishment success. For the invasive Argentine ant, Linepithema humile Mayr, there is limited information about the role of propagule size though it is one of the very successful invasive ants. Here, in a laboratory and natural environments, I manipulated number of workers to investigate the effect of propagule size on the survival and establishment of L. humile propagules. In the laboratory study, I introduced replicates of four different sized L. humile propagules (10,100, 200 and 1000 workers plus two queens per worker category) into foraging arena in the presence of 200 workers of the New Zealand native ant species, Monomorium antarcticum Smith, and also varied food densities. I found that at colony size of 10, 100 and 200 workers, L. humile only survived for a short time, but at colony size of 1000 workers, L. humile successfully resisted M. antarcticum colonies consisting of 200 workers and raised brood. I also examined the effect of propagule size and varying amounts of food on the aggressive behaviour of L. humile and M. antarcticum. Increasing colony size caused L. humile to display less benign interactions and more aggressive behaviours. On the other hand, M. antarcticum maintained high aggressive behaviour at colony size of 10, 100 and 200 workers, but the proportion of aggressive behaviours decreased at a colony size of 1000 workers. Food played an insignificant role on the survival and growth of L. humile. I replicated the laboratory study in the field using colonies of 10,100 & 1000 workers and one queen per worker category to test for the effect of propagule size, temperature and resident ant abundance on the survival of L. humile colonies. I also examined interspecific competition of the L. humile with resident ant species over sugar and tuna baits and measured their foraging distances. Contrary to the laboratory study, I found that none of the measured factors, including propagule size had a significant effect on the survival of the L. humile. Over half of the colonies in propagule sizes of 100 and 1000 workers survived longer than propagule size of 10 workers, but the mean survival times of all the propagule sizes were not significantly different. In all the propagule sizes, workers died first leaving the queens to survive alone about the same amount of time as with workers. Consequently, the mean survival time of colonies (queens with workers) was longer than mean survival time of workers in all the propagule sizes. Also, all the propagule sizes did not excel in exploitative or interference competitions. Linepithema humile in propagule size of 100 and 1000 workers discovered the baits in about the same amount of time (20-90 minutes) as native ant species, M. antarcticum but recruited very poorly to the baits. Consequently, L. humile never dominated the baits. Increasing L. humile propagule size increased foraging distance with propagule size of 1000 workers foraging the furthest distance. The results of laboratory and field studies provide first direct experimental evidence of the importance of propagule size during incipient colony establishment of L. humile. Propagule size of 1000 workers increased the ability of L. humile to resist M. antarcticum in the laboratory but failed to do so in the field condition. If propagule sizes of more than 1000 workers were used in the field a significant result would have been possible. However, the strong aggressive behaviour shown by M. antarcticum and failure of increasing propagule size to influence survival of L. humile in the field suggest that native habitats are difficult to invade. Therefore, incipient L. humile colonies that entered New Zealand may have done so in large colonies, perhaps containing more than 1000 workers. Sagolo, A. 2009.
Spatial Distribution and Hunting intensity of Hunted wildlife populations in
Sokamin, Sandaun Province. Honours thesis, University of Papua New Guinea. Hunting of wildlife populations has now been found to be a common threat to species extinction. Although Papua New Guinea has on-going hunting studies, much remains to be explored. I investigated the spatial distribution of hunted wildlife animals and predicted hunting intensity of eleven settlement hunt catchments of the Sokamin community in Sandaun Province. Statistically significant results showed that the mean number of animals killed varied between each hunt catchments (F1, 9 = 24.69, P = 0.000). There was a difference between hunter age groups (F = 0.8724, P = 0.000) and gender (χ2=268, P=0.000) in the number of animals they killed . Hunt catchment areas of the eleven settlements constituted of about 26km2 with less than 1% overlapping areas. Most animals killed was within the hunt catchment areas (χ2 = 103, P= 0.0028) than outside the mapped polygons, with seven of the eleven hunt catchments having more than 50% as undisturbed forest. Regardless of this, more animals were killed in human disturbed forest within the hunt catchments (F1, 9 = 32.445, P = 0.000) then primary forest. There was a significant difference in number of animals killed at the different elevations (F = 41.84, P = 0.000) with more animals killed in the lower slopes than the other four landform types (χ2 = 120, P = 0.000). Hunting intensity was much higher within a 1km radius from centre of settlements (χ2 = 26.0599, P = 0.000) but diminished the further hunters hunt from settlements. The number of taxa was positively correlated to distance from centre of settlements from four different buffer zones (R = 40, P = 0.008). Information from this study could be useful in setting up policies and strategies for better management of wildlife populations and hunting. Supuma, M. 2003.
Plant dynamics of a Papua New Guinean hill forest. Honours thesis,
University of Papua New Guinea. Little is known about the demography of rainforests in Papua New Guinea. I recensused 4.2 hectares of 0.1 ha plots in a hill to submontane forest 8 years after initial enumeration. In 1994 total basal area was 35.08 m2 ha-1 with 637.86 stems ha-1 while in 2002, basal area was 33.96 m2ha-1 with a density of 622.6 stems ha-1. The mean growth rate in diameter at breast height for trees was 0.29 cm per year. Larger trees had a higher absolute growth rate, but smaller trees had a faster growth rate for their size. Mortality of trees was not size dependent but was negatively correlated to density. The numbers of trees dying and being recruited per 0.1 ha plot were not correlated although an average of 17.95 trees ≥ 10 cm died and 16.04 were recruited ha-1yr-1 so that on a larger scale forest tree number remained relatively constant. There was no significant difference in the distribution of size classes of trees between censuses. The absence of net change in number of stems, basal area or size distribution suggests that this is a climax forest in equilibrium. Studies such as this give us knowledge of forest dynamics and tree demography in undisturbed sites, which can be compared to data from disturbed sites. Warakai, D. 2009.
Tree cavities, tree cavity-using wildlife, and experimenting with nest boxes in
Papua New Guinea. Honours thesis, University of Papua New Guinea. A tree cavity or tree hollow is an empty space within a tree, which wildlife may use for shelter. Tree cavities are being lost at an unchecked rate due to extensive logging and plantations in Papua New Guinea (PNG). While this is the case, there is little known on tree cavities and tree cavity-using fauna in PNG. Nest boxes have been used to help mitigate the effects of tree cavity loss. This study stands as a preliminary study into tree cavities, tree cavity-using fauna and nest boxes in PNG. In this study, I aimed to quantify the demand, supply and use of tree cavities by tree cavity-using fauna, and their use of nest boxes in PNG. A literature search was carried out to find out which of New Guinea’s bird and mammal species use tree cavities for nesting or denning. Cavity censuses were performed on a hectare each of primary and secondary forests in Wanang, Madang. 160 nest boxes were established in Wasu, Morobe, on four plots distinguished by elevation and forest age. Findings of this study revealed that 10.6% of New Guinea’s bird and mammal species are known to use cavities for nesting. Cavity trees were estimated at 26 cavity trees per ha in the unlogged forest, while in forest regrowth, there were zero cavity trees per ha. In this study, the nest box occupancy rate was 19.4% after 8 months. With loss of cavities from logging and plantations, and the subsequent loss of cavity-using fauna, there is opportunity to take up nest boxes as a management tool. Nest boxes can also serve as a research tool, given the lack of studies done on cavity-using species of New Guinea. Yhuanje, K. 2008.
Sustainability of hunting in Sokamin, Sandaun Province and maximum sustainable
percentage off-take of commonly hunted mammals in New Guinea. Honours thesis,
University of Papua New Guinea. Globally, habitat destruction and hunting are the recent major causes of species extinction. In Papua New Guinea, hunting is probably the most important threat to wild animal species. Sustainable resource use is a key to conserving biodiversity. As a step towards management of wild animal populations, I conducted a study to assess the sustainability of hunting by the Min in the Sokamin area of Star Mountains Papua New Guinea. The area inhabited by the Min is very isolated and typically the only source of protein is from wild animals which are extensively hunted. I used a set of three questionnaires containing both open ended and closed ended questions to obtain information on the hunter, the species hunted and the location of captures. I obtained data on the species diversity and the quantity of the animals hunted. Using the data collected from the field and from published life history data, I modeled the sustainability of harvest of the two most commonly hunted species. The survey showed that the most hunted taxa were mammals. Common echymipera (Echymipera kalubu) and ground cuscus (Phalanger gymnotis) made up over 50 percent of mammal captures. Hunting was opportunistic with these species being the most commonly taken because they were abundant. The model indicates the common Echymipera was harvested sustainably while the ground cuscus was not. The results suggest that K-selected mammals are more prone to over-harvesting and extinction than r-selected mammals. Hunters need to practice selective hunting with regards to the animals’ life history traits and thus their vulnerability to hunting. Education and awareness programs should be implemented to ensure sustainable harvesting of game species.
Staff & Student Publications | Relevant Board Publications
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