The mysterious case of the Carolina Parakeet: comparing patterns of range contraction to hypothesized extinction drivers
Authors:
Kevin R. Burgio1, Colin J. Carlson2, Alexander L. Bond3, Margaret A. Rubega1, Morgan W. Tingley1
1. University of Connecticut, Storrs, CT, USA, 2. National Socio-Environmental Synthesis Center, University of Maryland, Annapolis, MD, USA, 3. The Natural History Museum, Bird Group, Department of Life Sciences, Tring, United Kingdom
Abstract *
This year marks the centennial of the demise of the last captive Carolina Parakeet (Conuropsis carolinensis), yet why the only parrot endemic to North America north of Mexico, went extinct remains a mystery. We examined the spatio-temporal process of range contraction preceding the extinction of the Carolina Parakeet. Shedding light on the extinction process may help inform conservation of extant parrots, which comprise one of the most at-risk orders of birds. We developed a new model and R package, called spatExtinct, which uses Bayesian extinction date estimators and temporal occurrences to make spatially explicit predictions of extinction dates. We then applied this model to a detailed occurrence dataset of Carolina Parakeets and used Random Forest models to couple our spatial predictions of range loss with historic human population and land-use data. While extinction date models suggest that the species most likely lingered until the 1940s before going truly extinct, the eastern and western subspecies likely went extinct ~30 years apart. Human expansion and associated loss of grassland best predicted range loss for both subspecies, small amounts of settlement acting like leading indicators for disturbance. Conversion of forested land to cropland may have been a more important issue for the eastern subspecies than the western subspecies. This approach not only helps explain why, where, and when this iconic species went extinct, but the model also demonstrates the potential for exploring the drivers of range loss for other extinct or critically endangered species.
www.iocongressabstracts.com/abstract_summary.php?mode=public&abs_id=1464