Systematics, biogeography and conservation of Bald Uakaris (Cacajao Lesson, 1840)

Silva, FE

Abstract

Uakaris, genus Cacajao, possess adaptations to their unripe seed-focused diet and habitat preference for Amazonian flooded forest habitats. These include large procumbent canines (shared by the other 2 Pitheciinae, Chiropotes and Pithecia, large home ranges, and large group sizes). The diversity, evolution and phylogenetics of Pitheciinae are limited to few studies and their geographic distribution to a few records and localities. The overall goal of this study is to investigate the phylogenetic relationship of bald uakaris, genus Cacajao, using molecular data, and to get new information on its genetic diversity and geographic distribution to assess their taxonomic classification. The molecular analysis of the mitochondrial DNA supports the origin of the ancestral of Cacajao in the Western Amazon with the sister genus Chiropotes expanding to the Guiana and Brazilian shields during the Pleistocene. Therefore, the genus Cacajao had its diversification influenced by the formation of the flooded forests of Western Amazon during the process of drainage of the Pebas Lake. The ddRAD analysis supported the reciprocal monophyly of bald uakaris, with all clades including only individuals with exclusive diagnostic characters. Therefore, bald uakaris can be classified as follow: Cacajao calvus (I. Geoffroy, 1847), C. rubicundus (I. Geoffroy and Deville, 1848), C. ucayalii (Thomas, 1928), and C. novaesi (Hershkovitz, 1987). I provide an update of the geographic distribution of each species of bald uakari and how the predicted scenarios of deforestation and climate change can affect the four species by 2050. Cacajao novaesi has the more restricted geographic distribution occurring only between Gregorio and Tarauacá rivers. All other bald uakaris occur in a patchy distribution. The synergistic effects of climate change and deforestation will imply in habitat loss in the future scenarios, and along with hunting of C. ucayalii and C. novaesi, will result in a population decrease. Studies on the feeding ecology in different field sites and the population status for each taxon are the priorities for the research of bald uakaris.

Citation

Silva, F. Systematics, biogeography and conservation of Bald Uakaris (Cacajao Lesson, 1840). (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Aug 7, 2020
• Publicly Available Date: Aug 7, 2020
• Award Date: Jan 1, 2020