Field Journal: The Sound of Dawn in Guadalcanal

by AMNH on

From the Field posts

Chris Filardi is director of Pacific Programs at the Museum’s Center for Biodiversity and Conservation. This month, he’s blogging from the remote highlands of Guadalcanal in the Solomon Islands, where he is surveying endemic biodiversity and working with local partners to create a protected area. 

Dawn is a magical time, especially for those interested in birds, whose choruses of sound at first light in tropical forests is something to behold. That’s even more true in a place where biologists have yet to complete the most basic description of forest species and their sounds, meaning some of those songs remain mysteries.

Close-up on the head of a tiny fantail bird.
This tiny fantail has a unique dawn song that we have captured for the first time.
© AMNH/C. Filardi

Each morning, as the mostly nocturnal teams searching for frogs and mammals settle in for some sleep, bird people ascend the ridgelines to listen to the day awaken. Before first light, birds are still at their night roosts, often much lower in the forest than at any other time, and they sing. This morning song is likely for territorial and other social reasons, but anyone who has heard a tropical dawn must sense a more mystical response to the coming of a new day. 

As light approaches, Boobook owls finish their last rollicking duets just as whistler and monarch flycatcher songs rise from all directions. Leaf warblers and fantails chatter sweetly at shoulder height while doves—some colored like a child’s drawing, others the size of small chickens—whoop and coo, all combining into a unique soundscape of this place.

Sounds are one focus of our work here—many birdsongs of the species unique to this site are unknown. Others are poorly described, and most have never been recorded. Our work is already turning up interesting new findings, such as distinctive dawn songs, and documenting numerous undescribed calls. 

A brightly colored frog hands onto a thin branch with both hands and both feet.
Recordings made of this tree frog are the first ever.
© AMNH/C. Filardi

Beyond the vocalizations of single species, we are also capturing the collective sounds of the forests. These soundscapes are the context within which contemporary vocalizations evolved. But, just as many of the species here are threatened by mining operations along these ridgelines, soundscapes are threatened by alien species and the sounds from urbanization in the lowlands. 

For now, that is far below and the soundscapes we hear on this survey are only broken by the occasional incoming airplane or helicopter and our own voices threading through the undergrowth This is an ideal place to capture the sounds of a forest rich in species encountered nowhere else on Earth. 

A bumpy textured frog with deeply colored eyes sits on a leaf.
This frog was discovered by its odd barking calls in the night, and may be an undescribed species.
© AMNH/C. Filardi

The kind of listening we’re doing, with persistent audio recording at varied sites, has the potential to reveal rarely seen species, such as a beautiful forest kingfisher glimpsed just once by scientists, or a ground-dwelling thicketbird known only by one specimen gathered nearly a century ago.

The possible presence of these species around us has everyone electrified with a heightened awareness. Possible observation of and data from these birds and other potential new species of mammals, amphibians, and invertebrates is at the heart of our science. They are links in a grand biogeographic tapestry still being revealed, constantly being woven.