First record of avian extinctions from the Late Pleistocene and Holocene of Timor Leste
Summarized by Julie Sanchez, a senior at the University of South Florida who is majoring in Geology. She plans to graduate with her Bachelors of Science in summer of 2021 and wishes to continue her studies in graduate school, focused in petroleum geology. Outside of her academics, she loves to embrace her crafting side by painting or designing ceramic pieces. She also loves to walk trails and observe the beautiful rocks around her.
What data were used? The researchers collected fossil birds from excavated sites in Timor Leste and then used collections of bird skeletons from the Smithsonian Institution’s National Museum of Natural History in Washington D.C. and Bergen University Museum in Norway to identify the newly found fossils. Here, the researchers were able to obtain information on what kinds of bird skeletons were resided in Timor, as well as bird skeletons that may have migrated to Timor. Research from a previous study of these skeletons provided useful information on the taphonomy of birds in Timor that added to the understanding of the results in this article.
Methods: Researchers set up two locations of excavation in Timor: one in Jerimalaj and the second in Matja Kuru, both of which are located on the northeast part of Timor Leste (Figure 1). Using mesh screens, the researchers were able to wet the screens and expose the bone/fragments found. As the fossils began to appear, they were measured with a digital caliper. The texture and porosity levels of the fossilized skeletons were also noted, to help differentiate and categorize the juvenile bird bones from the mature bird bones. Radiocarbon dating was used to determine the ages of the bones/fragments found.
Results: The researchers recovered 416 bird bones from Jerimalai and Mataja Kuru. Throughout the excavation, there were more species found in Jerimalai than in Matia Kuru. Unfortunately, 65% of the fossils were not distinguishable. The reason for this was because most of bones were fragments, which only allowed them to narrow it down to being just a bird fossil. With the residual 147 identifiable fossilized specimens, it was determined that there were 29 bird species across 16 families. It was found that quails and buttonquail birds were more prominent at Maja Kuru, though they are considered rare in the city of Jerimalai today. There was also a crane species found that is extinct today. This represents the first known extinction event of birds in Timor. Their research also determined that although quails and buttonquails are morphologically similar, 29 different specimens were distinguished because of differences in bone structure. The results featured only a single fragment of Blue-breasted quail, S. chinensis, which was found in Jerimalai. Six specimens found in Jerimalai were determined as Metallic Pigeons. All of this information helps researchers better understand the modern day bird populations in this area/
Why is this study important? For about two hundred years, researchers have been studying the birds in this area. In spite of their research, the is still a big gap in regard to what kind of birds lived in Timor. This study allows the public to observe another perspective that was once “not there.” With the addition newly discovered bird species, it allows researchers to use this information in future studies of bird biodiversity, as well as understand what bird species coexisted during the Late Pleistocene and Holocene.
The big picture: Knowing what types of birds existed on Timor can gives us insight about the environments the birds lived in, as well as climate change, and the relationships these animals could have had with other organisms. By understanding what bird species were once there, we can better understand what Timor was like during the Late Pleistocene and Holocene. We can also use this information to better understand global sampling, as many areas of southeast Asia are still underexplored for fossils.
Citation: Meijer, Hanneke J. M., et al. “First Record of Avian Extinctions from the Late Pleistocene and Holocene of Timor Leste.” Quaternary Science Reviews, vol. 203, Jan. 2019, pp. 170–184. EBSCOhost, doi:10.1016/j.quascirev.2018.11.005.