Waria Valley Science Update, Papua New Guinea
Added to website: 17 December 2007
The science programme has been making steady progress since the first survey was carried out in June this year. So far the team has completed full surveys in nine different locations with many more areas identified for future work. Four habitat types are being looked at comprising of primary forest, disturbed-agricultural land, primary forest-disturbed edge and secondary forest-primary forest edge. Each survey lasts for a period of 4 nights/ 5 days and aims to collect data for herpetiles, small mammals, bats, birds, butterflies and vegetation. Over the course of the project each site will be surveyed at least three times ensuring that there is an equal and comparable survey effort for each one.
Herpetiles
PNG has a wealth of reptiles and frogs with many new species being described each year. The programme is surveying this group using a number of methods. First is through the use of drift fences which have proved to be very successful catching many elusive fossorial creatures, such as short-legged skinks, that would otherwise prove difficult to catch. The second is through timed searches of likely microhabitats, such as fallen logs and coconut husk piles. We have also begun recording frog calls which are an important aspect in identifying frogs as a number of physiologically similar new species have been described as a result of call analysis. So far we have caught over 50 different types of reptiles and amphibians, from tiny hylidae tree frogs to 2m long pythons! As there is only limited information available on the reptiles and frogs of PNG many of our finds have yet to be formally identified. However, with the help of Allen Allison of the Bishops Museum, Hawaii we are hopeful these will be identified in the near future, possibly; with some very exciting discoveries.
Bats and Mammals
The mammal fauna of PNG is unique, lacking many families found in other tropical countries, such as large predators and primates, but supports all three orders of mammal, the greatest diversity of murids (rats and mice) anywhere and one of largest number of bat species in the world. The bat surveys using mist nets have yielded lots of data with over 200 bats, representing eight different species, caught. This includes three species of tube-nosed bats which use their strange elongated nostrils to seek out ripe fruit.
Small terrestrial mammals are sampled using Sherman and cage traps baited with suitable bait, such as peanut butter or ripe banana. Capture rate is never high, given most small mammals nervous nature but around five different rat species, mostly endemic, have been caught. Additionally we have sighted a number of marsupials including bandicoots and cuscus; PNG’s ecological equivalent to foliverous monkeys of the tropics elsewhere. The use of different baits and more traps are being investigated to increase the chances of sampling more of the diverse mammal fauna present in PNG.
Birds
With over 700 species of birds and many families special to the island, PNG is an ornithologist’s paradise. The fact that spotting many species is notoriously difficult it makes it even more pleasing when they are spotted! So far around 90 species of birds have been positively identified in the Waria Valley. As well as the daily sightings of Blyth’s Hornbill’s, Sulphur-crested Cockatoo’s and various parrot species other enigmatic species have been spotted including King Bird of Paradise, Dwarf Cassowary and the geographically restricted endemic Brown-headed Paradise-kingfisher.
Mist nets and casual observations are used in addition to the main visual surveys, which are done using the Mackinnon List methodology. Surveys are done primarily in the early hours of the day around dawn when bird activity is greatest.
Butterflies
Butterflies are a very important group in biodiversity surveys, particularly within tropical ecosystems, as they are indicator species. The butterfly diversity can provide important information about the health and status of a particular area. At present we are using hand held sweep nets to catch butterflies, although this is not as easy as it sounds – they can move very fast! We are currently investigating the possibility of having some canopy traps made which will help sample those species that fly beyond the reach of a human arm and net.
Vegetation
The forest and in particular the plant species it supports are a vital resource for the rural communities. As such we are conducting vegetation surveys to collect information on the tree species and non-timber forest products present as well as providing a more detailed overview of the habitat within each survey site. This is being done using a standard methodology under the direction of our Field Scientist Oscar Pileng, a forestry graduate from Unitech. The team is also carrying out resource inventories in some areas at the request of the landowner.
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