The results of a citizen science study that used information from the Southern African Bird Atlas Project showed that about half of South Africa’s forest-dependent bird species are in decline. The populations in the most trouble are forest birds in the Eastern Cape. The findings were just published in the journal Bird Conservation International.
South Africa is home to a wide variety of birds, including parrots, finches, cranes, hawks, and even penguins. Many of these birds rely on forest habitats for survival and require trees for housing, nesting, protection, and food. Deforestation is a serious threat to these species as it results in less and less suitable habitat for birds. Human developments, such as woodlots and plantations, also lead to a phenomenon called habitat fragmentation. When specific parts of a forest are cut down, leaving useable forest in patches, it makes it difficult for animals to get from patch to patch. In some cases, roads and buildings further divide the forest. The forest becomes “fragmented” into many tiny unlinked ecosystems, restricting access to mates and resources for the animals living in these fragmented regions. Scientists had yet to quantify exactly how this process was affecting the local bird populations.
A team of researchers from Stellenbosch University collaborated with South Africa’s Department of Environmental Affairs to study recent population changes in 57 forest bird species. The data was from two citizen science projects: Southern African Bird Atlas Project (SABAP) and the Second Southern African Bird Atlas Project (SABAP2). The projects relied on field data from volunteers, mostly bird watchers, and helped researchers track bird populations and locations. The first survey started in 1987 and ended in 1992, while the second survey began in 2007 and is still running today. The amount of data collected through these projects far surpasses the data a small team of scientists could gather on their own, making the volunteers’ contributions invaluable.
After analyzing the data from both the SABAP and the SABAP2, the research team found that half of South Africa’s forest bird species were experiencing population declines. The sharpest population drops were in the Eastern Cape. Although the species affected the most were insectivores and birds of prey, the team didn’t notice any particular patterns. Some species were coping fine with deforestation while it was proving disastrous for others. The research team cannot say for sure whether the missing birds are dying out or have simply moved elsewhere; the SABAP2 project is ongoing so that scientists can continue to collect data.
The team’s findings show that South African forest-dwelling birds may require special protection as they continue to lose habitat. The researchers will continue to monitor the populations through the Southern African Bird Atlas Project 2, a citizen scientist database that is still online.