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Rosti H, Pihlström H, Rottcher N, Bearder S, Mwangala L, Maghenda M, Rikkinen J. Species identity and behavior of cave-dwelling tree hyraxes of the Kenyan coast. Ecol Evol 2023; 13:e9693. [PMID: 36687802 PMCID: PMC9841124 DOI: 10.1002/ece3.9693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/23/2022] [Accepted: 12/12/2022] [Indexed: 01/17/2023] Open
Abstract
We surveyed tree hyrax populations living in forests, limestone rocky formations, and caves in coastal Kenya to identify the species and estimate the threat-level populations are in. Tree hyrax vocalizations were recorded in three different habitats with passive acoustic monitoring (PAM) for a total of 84 h in January and February 2022. We also observed tree hyrax behavior with thermal imaging camera and photographed individuals. Tree hyraxes in coastal Kenya are vocally active throughout the night, with most calls emitted between 23.00 and 04.00. We identified four different calls: snort, hac, hac ping-pong, and wheeze. Their calling range is between 220 and 15,000 Hz. Calls of tree hyraxes from the coast of Kenya were compared with calls stored by the Oxford Brookes University's Nocturnal Primate Research Group and identified as eastern tree hyrax, previously recorded from Tanzania. Here, we present what are, to our knowledge, the first photographs of live D. validus from Kenya. These tree hyraxes live in social groups. Due to strong pressure from humans, conservation measures are necessary to prevent the extinction of these isolated D. validus populations in Kenya.
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Affiliation(s)
- Hanna Rosti
- Finnish Museum of Natural HistoryUniversity of HelsinkiHelsinkiFinland,Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | - Henry Pihlström
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | | | - Simon Bearder
- Nocturnal Primate Research GroupOxford Brookes UniversityOxfordUK
| | - Lucas Mwangala
- Programme and PlanningAcademic Research and Outreach DivisionTAITAGISTaita Taveta University (TTU)VoiKenya
| | - Marianne Maghenda
- Department of Agricultural SciencesSchool of Agriculture Earth and Environment SciencesTAITAGISTaita Taveta University (TTU)VoiKenya
| | - Jouko Rikkinen
- Finnish Museum of Natural HistoryUniversity of HelsinkiHelsinkiFinland,Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
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Rosti H, Heiskanen J, Loehr J, Pihlström H, Bearder S, Mwangala L, Maghenda M, Pellikka P, Rikkinen J. Habitat preferences, estimated abundance and behavior of tree hyrax (Dendrohyrax sp.) in fragmented montane forests of Taita Hills, Kenya. Sci Rep 2022; 12:6331. [PMID: 35428748 PMCID: PMC9012809 DOI: 10.1038/s41598-022-10235-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 04/04/2022] [Indexed: 11/13/2022] Open
Abstract
We studied a previously almost unknown nocturnal mammal, an apparently undescribed species of tree hyrax (Dendrohyrax sp.) in the moist montane forests of Taita Hills, Kenya. We used thermal imaging to locate tree hyraxes, observe their behavior, and to identify woody plants most frequently visited by the selective browsers. We also documented acoustic behavior in forest fragments of different sizes. Data on calling type and frequency were analyzed together with lidar data to estimate population densities and to identify forest stand characteristics associated with large populations. Viable populations were found only in the largest forest fragments (> 90 ha), where tree hyraxes preferred most pristine forest stands with high, multilayered canopies. The estimated population sizes in smaller forest fragments were very limited, and hyraxes were heard to call only during late night and early morning hours, presumably in order to avoid detection. While we frequently recorded tree hyrax songs in the largest forest fragments, we almost never heard songs in the small ones. All remaining subpopulations of the Taita tree hyrax are under threat of human disturbance and further habitat deterioration. Conservation efforts should include protection of all remaining habitat patches, but also reforestation of former habitat is urgently needed.
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Affiliation(s)
- Hanna Rosti
- Finnish Museum of Natural History, University of Helsinki, P.O. Box 7, 00014, Helsinki, Finland.
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, P. O. Box 65, 00014, Helsinki, Finland.
| | - Janne Heiskanen
- Department of Geosciences and Geography, Faculty of Science, University of Helsinki, P.O. Box 64, 00014, Helsinki, Finland
| | - John Loehr
- Lammi Biological Station, University of Helsinki, Pääjärventie 320, 16900, Lammi, Finland
| | - Henry Pihlström
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, P. O. Box 65, 00014, Helsinki, Finland
| | - Simon Bearder
- Nocturnal Primate Research Group, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Lucas Mwangala
- Programme and Planning, Academic Research and Outreach Division, TAITAGIS, Taita Taveta University (TTU), P. O. Box 635-80300, Voi, Kenya
| | - Marianne Maghenda
- Department of Agricultural Sciences, School of Agriculture Earth and Environment Sciences, TAITAGIS, Taita Taveta University (TTU), P. O. Box 635-80300, Voi, Kenya
| | - Petri Pellikka
- Department of Geosciences and Geography, Faculty of Science, University of Helsinki, P.O. Box 64, 00014, Helsinki, Finland
- Taita Research Station of University of Helsinki, P.O. Box 1156, Wundanyi, 80304, Taita Taveta, Kenya
| | - Jouko Rikkinen
- Finnish Museum of Natural History, University of Helsinki, P.O. Box 7, 00014, Helsinki, Finland.
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, P. O. Box 65, 00014, Helsinki, Finland.
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