Climate Impacts Species + Communities in Papua New Guinea

In the mountains of northern Papua New Guinea, Conservation International is collaborating with the Woodland Park Zoo and James Cook University on the YUS Conservation Program, which engages local communities in the long-term study and management of the 76,000-hectare (180,000-acre) YUS Conservation Area. CI’s Bruce Beehler reports on a summer of research in these remote mountains.

Black-mantled goshawk

Black-mantled goshawk (Accipiter melanochlamys), YUS transect, July 2011. (© Bruce Beehler )

I have been carrying out fieldwork in Papua New Guinea since 1975. Getting into the forest there remains exciting and fresh for me — a wonderful antidote to the overdose of technology-fostered information many of us experience in our office lives. This summer, our main field activity was a survey of birds along the YUS elevational transect, which ranges from 200 meters to 3,700 meters (656 to 12,140 feet) above sea level.

The elevational transect can be likened to a giant ‘earth thermometer.’ As the earth heats or cools, the plants and animals along the transect shift up and down the elevational gradient, seeking the best conditions for their own environmental needs. Surprisingly, the plants can move almost as quickly as the wildlife, as birds and mammals consume fruits and deposit the seeds in distant locations as they forage about the forest.

Jen Mandeville and Suzanne Tomassi examining birds netted on YUS transect. (© Bruce Beehler)

The transect itself is little more than a traditional walking track through the forest, which gives us foot access to natural habitats arrayed at different elevations. We sleep in mountain tents set around permanent campsites along the track. These rough bush camps tend to be situated near where we can get a ready supply of spring water to drink. Because the track follows the top of a ridge — the best place to walk in the mountain forest — water is limited.

Our international team of six scientists was supported by more than two dozen YUS field naturalists, who also are local landowners. Our local counterparts get a kick out of working and camping with us, and frankly, we could not do our work without them. They know the forest and wildlife, and have excellent ears and eyes for locating elusive species. We make a great team in the field.

Living in the forest is challenging but fun. We rise before dawn and work steadily until nightfall, because there is so much to do in each field season. Breakfast and lunch is little more than granola and biscuits; dinner is the substantial hot meal of the day and we take turns cooking, trying to make a delicious meal from the selection of camp foods we have on hand. Garlic and hot sauce are important additives to what otherwise is pretty underwhelming — mainly rice and stew. Still, we are so famished at the end of the day that the meal disappears quickly, often followed by hot sweet tea and perhaps some ginger-nut cookies to perk things up.

Large beetle from YUS transect.

Large beetle from YUS transect. (© CI/ Photo by Trond Larsen)

This season, rain was our constant companion. Above 2,500 meters (8,202 feet) elevation, the rain and cold made it difficult to keep warm out on the trail. It was a great luxury to slip into one’s dry and warm sleeping bag after dark for a much-deserved night of rest; the harsh sound of the alarm at 5:30 am came all too soon.

Working in two teams, we netted 3,861 birds of 128 species, and censused an additional 1,500 individuals by voice. The birds are captured unharmed in nylon mist-nets that are strung through the forest. I conducted sound surveys by recording all birds seen or heard from a series of survey points arrayed along a kilometer-long track at a particular elevation along the transect.

After research over a three-year period, we have detected several changes in bird distributions in these mountains. This may be caused by the changing climate; many species are ranging higher up the mountains, where it is cooler. This phenomenon has been observed in other tropical mountain ranges as well. More interestingly, some species are expanding downwards, and the abundance of some species is rising whereas others are decreasing. This is all happening because the forest bird communities are restructuring themselves to adapt to changing temperature and rainfall regimes.

Rural communities in Papua New Guinea are also being affected by climate change impacts. In early September, Kasbeth Evei — a CI contractor — began studying the impact of climate change on subsistence agriculture in villages along the elevational gradient. His study is documenting how gardening practices are changing and how local farmers are adapting to these changes.

Schoolchildren celebrating World Environment Day in Sapmanga Village, Papua New Guinea, June 2011.

Schoolchildren celebrating World Environment Day in Sapmanga Village, Papua New Guinea, June 2011. (©CI/Photo by Trond Larsen)

Local communities are well aware of the growing impacts of climate change, because they can see the effects in their gardens. It is a matter of having enough food to eat. They note that the list of crops they can grow has changed over the last 30 years, and the array of crop pests has changed as well. They complain that the annual seasons, which used to be well-defined, are much less predictable, making garden planning more difficult.

Once our study is complete, we hope to gather a wide range of “lessons learned” from the many gardeners we are interviewing and share these with communities throughout Papua New Guinea. We are planning several more field seasons in YUS to study the birds and the gardens, which should help us better understand how humans and other species can adapt to the impacts of climate change.

Bruce Beehler is the senior director of biodiversity assessment in CI’s Science and Knowledge division. He also leads the science component of the YUS Conservation Program.

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