Original Research Article Folia Primatol 2017;88:323–332 DOI: 10.1159/000479404
Received: July 7, 2015 Accepted after revision: June 12, 2017 Published online: October 11, 2017
Impact of Typhoon Haiyan on a Philippine Tarsier Population Sharon Gursky a Cristina Salibay c Nanda Grow b Lori Fields a a
Department of Anthropology, Texas A&M University, College Station, TX, and Department of Sociology, Social Work and Anthropology, Utah State University, Logan, UT, USA; c College of Science and Mathematics, De La Salle University-Dasmarinas, Dasmarinas City, Philippines b
Keywords Natural disaster · Conservation · Population density · Bohol · Primate
© 2017 S. Karger AG, Basel E-Mail [email protected] www.karger.com/fpr
Dr. Sharon Gursky Department of Anthropology, Texas A&M University MS 4352 College Station, TX 77843-4352 (USA) E-Mail gursky @ tamu.edu
Downloaded by: Göteborgs Universitet 130.241.16.16 - 10/15/2017 8:19:22 PM
Abstract Over the last 2 decades the Philippine tarsier (Carlito syrichta aka Tarsius syrichta) has had its conservation status revised from Endangered to Data Deficient to Near Threatened. The last status change was based on a study of the species’ population density, which suggested that a single natural catastrophe could potentially wipe out the Philippine tarsier. In 2013 typhoon Haiyan hit Bohol, one of the island strongholds for this species. In this study we compare the density of the Bohol tarsier population within the Philippine Tarsier and Wildlife Sanctuary before and after the typhoon. We demonstrate that the typhoon significantly affected the density of the Philippine tarsier in the sanctuary. Before the typhoon, tarsier density was approximately 157 individuals/km2 whereas after the typhoon the density was a mere 36 individuals/km2. Prior to the typhoon, more Philippine tarsiers were found in older secondary forest than in younger secondary forest, whereas after the typhoon all observed individuals were found in relatively younger secondary forest. Vegetation plots where we observed Philippine tarsiers prior to the typhoon contained a mean of 33 trees/m2, with a mean diameter at breast height (DBH) of 24 cm, and a mean height of 4 m. After the typhoon vegetation plots contained an average of 156 trees, had a mean DBH of 6 cm, and a mean height of 2 m. Based on the IUCN Red List criteria, the reduction and fluctuation in the density of this species suggests that the conservation status of the Philippine tarsier should be changed to Vulnerable. This study indicates natural disasters can have a significant effect on the extinction risk of primates, with implications for future effects of anthropogenic climate change. © 2017 S. Karger AG, Basel
Introduction
In 1986, in response to the rapid habitat destruction throughout the Philippine archipelago, the Philippine tarsier (Tarsius syrichta or Carlito syrichta) was classified as Endangered, indicating a high risk of extinction in the wild [Wolfheim, 1986]. In 2000, the conservation status of the Philippine tarsier was reclassified as Data Deficient as scientists admitted that they knew very little about the Philippine tarsier’s population density, distribution, or even the number of species/subspecies that existed [Shekelle and Arboleda, 2008]. The issue of conservation is further compounded by the taxonomic uncertainty of subspecies within and across the islands. Current subspecies designations for populations based on geographic divisions between the islands of Bohol, Samar-Leyte, and Mindanao [Brandon-Jones et al., 2004] have not been found to represent true genetic variation among Philippine tarsiers [Brown et al., 2014]. Although there is much uncertainty concerning the taxonomic boundaries for conservation, it is clear that all tarsiers in the Philippines are under threat of severe habitat loss. In 2001, the conservation status of the Philippine tarsier was again reclassified as Near Threatened due to a reported significant decline (
Received: July 7, 2015 Accepted after revision: June 12, 2017 Published online: October 11, 2017
Impact of Typhoon Haiyan on a Philippine Tarsier Population Sharon Gursky a Cristina Salibay c Nanda Grow b Lori Fields a a
Department of Anthropology, Texas A&M University, College Station, TX, and Department of Sociology, Social Work and Anthropology, Utah State University, Logan, UT, USA; c College of Science and Mathematics, De La Salle University-Dasmarinas, Dasmarinas City, Philippines b
Keywords Natural disaster · Conservation · Population density · Bohol · Primate
© 2017 S. Karger AG, Basel E-Mail [email protected] www.karger.com/fpr
Dr. Sharon Gursky Department of Anthropology, Texas A&M University MS 4352 College Station, TX 77843-4352 (USA) E-Mail gursky @ tamu.edu
Downloaded by: Göteborgs Universitet 130.241.16.16 - 10/15/2017 8:19:22 PM
Abstract Over the last 2 decades the Philippine tarsier (Carlito syrichta aka Tarsius syrichta) has had its conservation status revised from Endangered to Data Deficient to Near Threatened. The last status change was based on a study of the species’ population density, which suggested that a single natural catastrophe could potentially wipe out the Philippine tarsier. In 2013 typhoon Haiyan hit Bohol, one of the island strongholds for this species. In this study we compare the density of the Bohol tarsier population within the Philippine Tarsier and Wildlife Sanctuary before and after the typhoon. We demonstrate that the typhoon significantly affected the density of the Philippine tarsier in the sanctuary. Before the typhoon, tarsier density was approximately 157 individuals/km2 whereas after the typhoon the density was a mere 36 individuals/km2. Prior to the typhoon, more Philippine tarsiers were found in older secondary forest than in younger secondary forest, whereas after the typhoon all observed individuals were found in relatively younger secondary forest. Vegetation plots where we observed Philippine tarsiers prior to the typhoon contained a mean of 33 trees/m2, with a mean diameter at breast height (DBH) of 24 cm, and a mean height of 4 m. After the typhoon vegetation plots contained an average of 156 trees, had a mean DBH of 6 cm, and a mean height of 2 m. Based on the IUCN Red List criteria, the reduction and fluctuation in the density of this species suggests that the conservation status of the Philippine tarsier should be changed to Vulnerable. This study indicates natural disasters can have a significant effect on the extinction risk of primates, with implications for future effects of anthropogenic climate change. © 2017 S. Karger AG, Basel
Introduction
In 1986, in response to the rapid habitat destruction throughout the Philippine archipelago, the Philippine tarsier (Tarsius syrichta or Carlito syrichta) was classified as Endangered, indicating a high risk of extinction in the wild [Wolfheim, 1986]. In 2000, the conservation status of the Philippine tarsier was reclassified as Data Deficient as scientists admitted that they knew very little about the Philippine tarsier’s population density, distribution, or even the number of species/subspecies that existed [Shekelle and Arboleda, 2008]. The issue of conservation is further compounded by the taxonomic uncertainty of subspecies within and across the islands. Current subspecies designations for populations based on geographic divisions between the islands of Bohol, Samar-Leyte, and Mindanao [Brandon-Jones et al., 2004] have not been found to represent true genetic variation among Philippine tarsiers [Brown et al., 2014]. Although there is much uncertainty concerning the taxonomic boundaries for conservation, it is clear that all tarsiers in the Philippines are under threat of severe habitat loss. In 2001, the conservation status of the Philippine tarsier was again reclassified as Near Threatened due to a reported significant decline (
