Informing Aerial Total Counts with Demographic Models

Population Growth of Serengeti Elephants Not Explained Purely by Demography

Thomas A. Morrison, Anna Bond Estes, Simon A.R. Mduma, Honori T. Maliti, Howard Frederick, Hamza Kija, Machoke Mwita, A. R.E. Sinclair, Edward M. Kohi

Research output: Contribution to journalLetter

4 Citations (Scopus)

Abstract

Conservation management is strongly shaped by the interpretation of population trends. In the Serengeti ecosystem, Tanzania, aerial total counts indicate a striking increase in elephant abundance compared to all previous censuses. We developed a simple age-structured population model to guide interpretation of this reported increase, focusing on three possible causes: (1) in situ population growth, (2) immigration from Kenya, and (3) differences in counting methodologies over time. No single cause, nor the combination of two causes, adequately explained the observed population growth. Under the assumptions of maximum in situ growth and detection bias of 12.7% in previous censuses, conservative estimates of immigration from Kenya were between 250 and 1,450 individuals. Our results highlight the value of considering demography when drawing conclusions about the causes of population trends. The issues we illustrate apply to other species that have undergone dramatic changes in abundance, as well as many elephant populations.

Original languageEnglish (US)
Article numbere12413
JournalConservation Letters
Volume11
Issue number3
DOIs
StatePublished - May 1 2018

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Elephantidae
elephant
demography
immigration
census
population growth
demographic statistics
conservation management
Kenya
methodology
ecosystem
Tanzania
population trend
in situ
ecosystems
detection

All Science Journal Classification (ASJC) codes

  • Ecology, Evolution, Behavior and Systematics
  • Ecology
  • Nature and Landscape Conservation

Cite this

Morrison, T. A., Estes, A. B., Mduma, S. A. R., Maliti, H. T., Frederick, H., Kija, H., ... Kohi, E. M. (2018). Informing Aerial Total Counts with Demographic Models: Population Growth of Serengeti Elephants Not Explained Purely by Demography. Conservation Letters, 11(3), [e12413]. https://doi.org/10.1111/conl.12413
Morrison, Thomas A. ; Estes, Anna Bond ; Mduma, Simon A.R. ; Maliti, Honori T. ; Frederick, Howard ; Kija, Hamza ; Mwita, Machoke ; Sinclair, A. R.E. ; Kohi, Edward M. / Informing Aerial Total Counts with Demographic Models : Population Growth of Serengeti Elephants Not Explained Purely by Demography. In: Conservation Letters. 2018 ; Vol. 11, No. 3.
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Morrison, TA, Estes, AB, Mduma, SAR, Maliti, HT, Frederick, H, Kija, H, Mwita, M, Sinclair, ARE & Kohi, EM 2018, 'Informing Aerial Total Counts with Demographic Models: Population Growth of Serengeti Elephants Not Explained Purely by Demography', Conservation Letters, vol. 11, no. 3, e12413. https://doi.org/10.1111/conl.12413

Informing Aerial Total Counts with Demographic Models : Population Growth of Serengeti Elephants Not Explained Purely by Demography. / Morrison, Thomas A.; Estes, Anna Bond; Mduma, Simon A.R.; Maliti, Honori T.; Frederick, Howard; Kija, Hamza; Mwita, Machoke; Sinclair, A. R.E.; Kohi, Edward M.

In: Conservation Letters, Vol. 11, No. 3, e12413, 01.05.2018.

Research output: Contribution to journalLetter

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AU - Estes, Anna Bond

AU - Mduma, Simon A.R.

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AU - Frederick, Howard

AU - Kija, Hamza

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AU - Sinclair, A. R.E.

AU - Kohi, Edward M.

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