Type
Text
Type
Dissertation
Advisor
Akcakaya, Haluk R | Ginzburg, Lev | Graham, Catherine | Thogmartin, Wayne.
Date
2013-12-01
Keywords
Conservation biology | climate change, extinction risk assessment, passsenger pigeon, population modeling, population viability analysis, red-listing
Department
Department of Ecology and Evolution.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/77400
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Effective conservation of biological diversity requires accurate assessments of species extinction risks. Both under- and over-estimating extinction risks can have serious consequences. Overlooking species that are in need of conservation management can result in extinction or expensive recovery efforts. Misidentifying species which have stable populations as threatened can misdirect limited conservation resources or unnecessarily halt economic activity and development. I used a retrospective multi-modeling framework to explore the extinction of a once abundant and wide-spread North American species, the Passenger Pigeon (Ectopistes migratorius). I simulated three different types of anthropogenic impacts: harvest, habitat loss, and nest disturbance. I explored the effect of these impacts in conjunction with a range of life-history parameters through a global sensitivity analysis. I found that over-harvest and accompanying nest disturbance, rather than habitat loss were the primary impact factors driving this species to extinction. I extended this analysis by looking at the population trajectories generated by the model to illustrate how the International Union for the Conservation of Nature (IUCN) Red List criteria, a globally recognized method of assessing extinction risk, might have been used as an early warning system to identify the threats the species was facing well before extinction was imminent. I demonstrate that data collection and monitoring the population trends through time would have been necessary to identify the threat early on. Waiting until population sizes were reduced to critical thresholds would likely have only provided a few years of advance warning before the extinction of this species. In a related study, to gain a better understanding of how the IUCN Red List criteria may perform in the future under the threat of global climate change, I applied the Red List criteria to an ensemble of models representing endemic North American reptile and amphibian species, with a wide range of life-history characteristics, range sizes, and habitat types. Overall, I found that the Red List criteria reliably provided a sensitive and precautionary way to assess extinction risk due to climate change. Together, these case-studies demonstrate the ability of currently used methods to assess extinction risks under a variety of threats, and highlight the need for data collection and monitoring of wildlife species, particularly when simultaneously facing multiple impact factors. Heading into the future, preventing further loss of species will require much vigilance. The process of ranking species according to their threat status can provide an organized framework to help identify gaps in knowledge and guide data collection and conservation effort. | 98 pages
Recommended Citation
Stanton, Jessica Carol, "Extinction risk assessment as a tool for biological conservation" (2013). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 3216.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/3216