1
|
Tédonzong LRD, Ndju'u MBM, Tchamba M, Angwafo TE, Lens L, Tagg N, Willie J. The influence of vegetation structure on sleeping site selection by chimpanzees (Pan troglodytes troglodytes). Am J Primatol 2023:e23505. [PMID: 37157167 DOI: 10.1002/ajp.23505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 04/17/2023] [Accepted: 04/29/2023] [Indexed: 05/10/2023]
Abstract
Sleep is an important aspect of great ape life; these animals build sleeping platforms every night. In a community of chimpanzees, each subgroup selects a sleeping site where each individual builds a sleeping platform, mostly on a tree. Previous studies have measured the heights of sleeping platforms and sleeping trees to test the predation avoidance and thermoregulation hypotheses of sleeping site selection. However, it remains unclear how components of vegetation structure (vertical and horizontal) together determine the selection of sleeping sites by chimpanzees. Using botanical inventories around sleeping sites in a tropical rainforest of Cameroon, we found that chimpanzees preferentially sleep in trees measuring 40-50 cm in diameter. Regarding height, on average, sleeping trees measured 26 m and sleeping platforms were built at 16 m. To build sleeping platforms, chimpanzees preferred four tree species, which represent less than 3% of tree species in the study area. We demonstrate that the variation in abundance of tree species and the vertical and horizontal structure of the vegetation drive chimpanzee sleeping site selection. It was previously thought that preference for vegetation types was the driver of sleeping site selection in chimpanzees. However, results from this study indicate that the importance of vegetation types in sleeping site selection depends on their botanical characteristics including the variation in tree size, the abundance of all trees, the abundance of sleeping trees, and the occurrence of preferred sleeping tree species, which predict sleeping site selection. The height and diameter of trees are considered by chimpanzees when selecting a particular tree for sleeping and when selecting a site with a specific vertical structure. In addition to tree height, the abundance of smaller neighboring trees may also play a role in the chimpanzee antipredation strategy. Our results demonstrate that chimpanzees consider several vegetation parameters to establish sleeping sites.
Collapse
Affiliation(s)
- Luc Roscelin Dongmo Tédonzong
- Projet Grands Singes (PGS), Yaoundé, Cameroon
- Centre for Research and Conservation (CRC), Royal Zoological Society of Antwerp (RZSA), Antwerp, Belgium
- Section on Great Apes, Primate Specialist Group, IUCN Species Survival Commission, Yaoundé, Cameroon
| | | | - Martin Tchamba
- Department of Forestry, University of Dschang, Dschang, Cameroon
| | | | - Luc Lens
- Department of Biology, Ghent University (UGent), Ghent, Belgium
| | - Nikki Tagg
- Projet Grands Singes (PGS), Yaoundé, Cameroon
- Centre for Research and Conservation (CRC), Royal Zoological Society of Antwerp (RZSA), Antwerp, Belgium
| | - Jacob Willie
- Projet Grands Singes (PGS), Yaoundé, Cameroon
- Centre for Research and Conservation (CRC), Royal Zoological Society of Antwerp (RZSA), Antwerp, Belgium
- Department of Biology, Ghent University (UGent), Ghent, Belgium
| |
Collapse
|
2
|
Vanthomme HPA, Nzamba BS, Alonso A, Todd AF. Empirical selection between least-cost and current-flow designs for establishing wildlife corridors in Gabon. Conserv Biol 2019; 33:329-338. [PMID: 30022531 DOI: 10.1111/cobi.13194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 06/05/2018] [Accepted: 07/13/2018] [Indexed: 06/08/2023]
Abstract
Corridors are intended to increase species survival by abating landscape fragmentation resulting from the conversion of natural habitats into human-dominated matrices. Conservation scientists often rely on 1 type of corridor model, typically the least-cost model or current-flow model, to construct a linkage design, and their choice is not usually based on theory or empirical evidence. We developed a method to empirically confirm whether corridors produced by these 2 models are used by target species under current landscape conditions. We applied this method in the Gamba landscape between 2 national parks in southwestern Gabon. We collected signs of presence of African forest elephant (Loxodonta cyclotis), forest buffalo (Syncerus caffer nanus), and 2 apes, western lowland gorilla (Gorilla gorilla gorilla) and central chimpanzee (Pan troglodytes troglodytes), on transects. We used patch-occupancy models to identify least-cost and current-flow corridors for these 4 species. On average, 28.7% of current-flow corridors overlapped with least-cost corridors, confirming that the choice of corridor model can affect the location of the resulting linkage design. We validated these corridors by monitoring signs and examining camera detections on new transects within and outside modeled corridors. Current-flow corridors performed better than least-cost corridors for elephants, whereas the opposite was found for buffalo and apes. Locations of the highest priority corridors for the 3 taxa did not overlap, and only 18.3% of their combined surface was common among 2 species. We used centrality metrics to calculate the average contribution of corridor pixels to landscape connectivity and derived an index that can be used to prioritize corridors. As a result, we recommend protecting at least 17.4% of the land surface area around Gamba town to preserve the preferred travel routes of the target species.
Collapse
Affiliation(s)
- Hadrien P A Vanthomme
- Center for Conservation and Sustainability, Smithsonian Conservation Biology Institute, P.O. Box 37012, MRC 705, Washington, D.C. 20013-7012, U.S.A
| | - Brave S Nzamba
- World Wildlife Fund, Gabon Country Program Office, Montée de Louis, BP 9144, Libreville, Gabon
| | - Alfonso Alonso
- Center for Conservation and Sustainability, Smithsonian Conservation Biology Institute, P.O. Box 37012, MRC 705, Washington, D.C. 20013-7012, U.S.A
| | - Angelique F Todd
- Center for Conservation and Sustainability, Smithsonian Conservation Biology Institute, P.O. Box 37012, MRC 705, Washington, D.C. 20013-7012, U.S.A
| |
Collapse
|