A South African study has found that the number of Secretary Birds (Sagittarius serpentarius) appears to be in decline, particularly in the Kruger National Park. The study, which was published in the free online journal (PLOS One), used data collected in the Southern African Bird Atlas Project and the Coordinated Avifaunal Roadcounts project.
"Habitat data from the Coordinated Avifaunal Road counts (CAR) project show that this species tends to avoid transformed habitats across most of the area covered by this project," the researchers wrote, however this didn't explain what they found with the Atlas project.
After analysing the data collected on secretary birds from the Atlas project scientists found to their dismay that the Secretary bird population has decreased across much of South Africa.
"Worryingly, there were almost uniformly decreased reporting rates throughout the Kruger National Park, South Africa's largest formal conservation area, which is often considered to be an important refuge for many large, threatened bird species, especially raptors," the researchers wrote.
According to the study, climate change may play a part in this decline. The Secretary bird chooses open country, mainly Savannah, open woodland, grassland and dwarf shrubland. These habitat preferences are confirmed by relatively high reporting rates in the Karoo, Kalahari, Grassland, Mpane, Miombo and Woodland vegetation types.
However, with increasing carbon dioxide in the atmosphere the Kruger National Park is becoming more woody.
"Support for this hypothesis is provided by a study conducted in Swaziland, in which bush encroachment (increase in dense woody vegetation in previously open habitat) was confirmed to be occurring and was found to have a strong effect on bird abundances," the researchers wrote.
The Southern African Bird Atlas Project project uses reports from general citizens to figure out what is happening with our local bird species. If you want to take part, you can register as an observer on the project's website http://sabap2.adu.org.za/howto.php