Spatio‐temporal changes in chimpanzee density and abundance in the Greater Mahale Ecosystem, Tanzania

Journal article


Joana S. Carvalho, Fiona A. Stewart, Tiago A. Marques, Noemie Bonnin, Lilian Pintea, Adrienne Chitayat, Rebecca Ingram, Richard J. Moore, Alex K. Piel and Carvalho, J. 2022. Spatio‐temporal changes in chimpanzee density and abundance in the Greater Mahale Ecosystem, Tanzania. Ecological Applications. pp. 1-41. https://doi.org/10.1002/eap.2715
AuthorsJoana S. Carvalho, Fiona A. Stewart, Tiago A. Marques, Noemie Bonnin, Lilian Pintea, Adrienne Chitayat, Rebecca Ingram, Richard J. Moore, Alex K. Piel and Carvalho, J.
Abstract

Species conservation and management require reliable information about animal distribution and population size. Better management actions within a species’ range can be achieved by identifying the location and timing of population changes. In the Greater Mahale Ecosystem (GME), western Tanzania, deforestation due to the expansion of human settlements and agriculture, annual burning, and logging are known threats to wildlife. For one of the most charismatic species, the Endangered eastern chimpanzee (Pan troglodytes schweinfurthii), about 75% of the individuals are distributed outside national park boundaries, requiring monitoring and protection efforts over a vast landscape of various protection statuses. These efforts are especially challenging when we lack data on trends in density and population size. To predict spatio-temporal chimpanzee density and abundance across the GME, we employed density surface modelling, fitting a generalised additive model to a ten-year time series data set of nest counts based on line transect surveys. Chimpanzee population declined at an annual rate of 2.41%, including declines of 1.72% in riparian forests (hereafter forests), 2.05% in miombo-woodlands (hereafter woodlands) and 3.45% in non-forests. These population declines were accompanied by ecosystem-wide declines in vegetation types of 1.36% and 0.32% per year for forests and woodlands, respectively; we estimated an annual increase of 1.35% for non-forests. Our model predicted the highest chimpanzee density in forests (0.86 chimpanzees/km2, 95% CI 0.60-1.23; as of 2020), followed by woodlands (0.19, 95% CI 0.12-0.30) and non-forests (0.18, 95% CI 0.10-1.33). Although forests represent only 6% of the landscape, they support nearly a quarter of the chimpanzee population (769 chimpanzees, 95% CI 536-1,103). Woodlands dominate the landscape (71%) and thus support more than a half of the chimpanzee population (2,294; 95% CI 1,420-3,707). The remaining quarter of the landscape is represented by non-forests and supports another quarter of the chimpanzee population (750; 95% CI 408-1,381). Given the pressures on the remaining suitable habitat in Tanzania and the need of chimpanzees to access both forest and woodland vegetation to survive, we urge future management actions to increase resources and expand the efforts to protect critical forest and woodland habitat and promote strategies and policies that more effectively prevent irreversible losses. We suggest that regular monitoring programmes implement a systematic random design to effectively inform and allocate conservation actions and facilitate inter-annual comparisons for trend-monitoring, measuring conservation success and guiding adaptive management.

KeywordsConservation; detection function estimation; great apes
Year2022
JournalEcological Applications
Journal citationpp. 1-41
PublisherEcological Society of America
ISSN1051-0761
Digital Object Identifier (DOI)https://doi.org/10.1002/eap.2715
Web address (URL)https://doi.org/10.1002/eap.2715
Output statusPublished
Publication dates
Online02 Aug 2022
Dec 2022
Publication process dates
Accepted16 Jun 2022
Deposited05 Sep 2022
Supplemental file
License
File Access Level
Open
Permalink -

https://repository.derby.ac.uk/item/98574/spatio-temporal-changes-in-chimpanzee-density-and-abundance-in-the-greater-mahale-ecosystem-tanzania

Download files


Supplemental file
Appendix S1.pdf
License: CC BY 4.0
File access level: Open

  • 40
    total views
  • 14
    total downloads
  • 1
    views this month
  • 0
    downloads this month

Export as

Related outputs

Exploring the user experience, quality, and provision of urban greenspace: A mixed-method approach
Creed, C. and Carvalho, J. 2024. Exploring the user experience, quality, and provision of urban greenspace: A mixed-method approach. Urban Forestry and Urban Greening. 100, pp. 1-11. https://doi.org/10.1016/j.ufug.2024.128470
Exposure of African ape sites to climate change impacts
Kiribou, R., Tehoda, P., Chukwu, O., Bempah, G., Kühl, H. S., Ferreira, J., Sop, T., Carvalho, J., Mengel, M., Kulik, L., Samedi Mucyo, J. P., van der Hoek, Y. and Heinicke, S. 2024. Exposure of African ape sites to climate change impacts. PLOS Climate. 3 (2), pp. 1-19. https://doi.org/10.1371/journal.pclm.0000345
Range‐wide indicators of African great ape density distribution
Carvalho, J. S. 2021. Range‐wide indicators of African great ape density distribution. American Journal of Primatology. 83 (12), p. e23338. https://doi.org/10.1002/ajp.23338
Quantitative Estimates of Glacial Refugia for Chimpanzees (Pan troglodytes) since the Last Interglacial (120,000 BP)
Carvalho, J. S. 2021. Quantitative Estimates of Glacial Refugia for Chimpanzees (Pan troglodytes) since the Last Interglacial (120,000 BP). American Journal of Primatology. 83 (10), pp. 1-18. https://doi.org/10.1002/ajp.23320
Predicting Range Shifts of African Apes and Effectiveness of Protected Areas under Global Change Scenarios
Carvalho, J.S., Bruce, G., Maisels, F., Williamson, E. A., Wich, S., Sop, T. and Kühl, H. S. 2021. Predicting Range Shifts of African Apes and Effectiveness of Protected Areas under Global Change Scenarios. Gorilla Journal. 63, pp. 16-18.
Predicting range shifts of African apes under global change scenarios
Joana S. Carvalho, Bruce Graham, Gaёlle Bocksberger, Fiona Maisels, Elizabeth A. Williamson, Serge Wich, Tenekwetche Sop, Bala Amarasekaran, Richard A. Bergl, Christophe Boesch, Hedwige Boesch, Terry M. Brncic, Bartelijntje Buys, Rebecca Chancellor, Emmanuel Danquah, Osiris A. Doumbé, Anh Galat-Luong, Jessica Ganas, Sylvain Gatti, Andrea Ghiurghi, Annemarie Goedmakers, Nicolas Granier, Dismas Hakizimana, Barbara Haurez, Josephine Head, Ilka Herbinger, Annika Hillers, Sorrel Jones, Eno-Nku Manasseh, Maureen S. McCarthy, Bethan J. Morgan, Stuart Nixon, Louis Nkembi, Emmanuelle Normand, Sarah H. Olson, Leon Payne, Charles-Albert Petre, Alex K. Piel, Lilian Pintea, Andrew J. Plumptre, Aaron Rundus, Adeline Serckx, Fiona A. Stewart, Jacqueline Sunderland-Groves, Nikki Tagg, Angelique Todd, Ashley Vosper, José Francisco Carminatti Wenceslau, Erin G. Wessling, Jacob Willie, Hjalmar Kühl and Carvalho, J. 2021. Predicting range shifts of African apes under global change scenarios. Diversity and Distributions. 27, pp. 1663-1679. https://doi.org/10.1101/2020.06.25.168815
Advancing Conservation Planning for Western Chimpanzees Using IUCN/SSC A.P.E.S. – The Case of a Taxon-Specific Database
Carvalho, J. S. 2019. Advancing Conservation Planning for Western Chimpanzees Using IUCN/SSC A.P.E.S. – The Case of a Taxon-Specific Database. Environmental Research Letters. 14, pp. 1-13. https://doi.org/10.1088/1748-9326/ab1379
Characteristics of Positive Deviants in Western Chimpanzee Populations
Carvalho, J. 2019. Characteristics of Positive Deviants in Western Chimpanzee Populations. Frontiers in Ecology and Evolution. 7, pp. 1-14. https://doi.org/10.3389/fevo.2019.00016
A global risk assessment of primates under climate and land use/cover scenarios
Carvalho, J. S., Bruce, G., Rebelo, H., Bocksberger, G., Meyer. C. F. J., Wich. S. and Kuehl, H. S. 2019. A global risk assessment of primates under climate and land use/cover scenarios. Global Change Biology. 25 (9), pp. 3163-3178. https://doi.org/10.1111/gcb.14671
Chimpanzee (Pan troglodytes verus) Diet Composition and Food Availability in a Human-Modified Landscape at Lagoas de Cufada Natural Park, Guinea-Bissau
Carvalho, J. S., Vicente, L. and Marques, T. A. 2015. Chimpanzee (Pan troglodytes verus) Diet Composition and Food Availability in a Human-Modified Landscape at Lagoas de Cufada Natural Park, Guinea-Bissau. International Journal of Primatology. 36, pp. 802-822. https://doi.org/10.1007/s10764-015-9856-y
Where to Nest? Ecological Determinants of Chimpanzee Nest Abundance and Distribution at the Habitat and Tree Species Scale
Carvalho, J. S., Meyer, C. F. J., Vicente, L. and Marques, T. A. 2014. Where to Nest? Ecological Determinants of Chimpanzee Nest Abundance and Distribution at the Habitat and Tree Species Scale. American Journal of Primatology. 77, pp. 186-199. https://doi.org/10.1002/ajp.22321
Population Status of Pan troglodytes verus in Lagoas de Cufada Natural Park, Guinea-Bissau
Carvalho, J. S., Maques, T. A. and Vicente, L. 2013. Population Status of Pan troglodytes verus in Lagoas de Cufada Natural Park, Guinea-Bissau. PLos ONE. 8 (8), p. e71527. https://doi.org/10.1371/journal.pone.0071527