AI satellite survey returns fewer than 600,000, and is contested
Duporge and colleagues applied UNet and YOLO models to 33–60 cm satellite imagery from 2022 and 2023, counting roughly 300,000 and 500,000 animals respectively and concluding fewer than 600,000 migrate annually. The authors framed the result as complementary to aerial work and noted that differences in timing, coverage and method could explain much of the gap; Grant Hopcraft called it 'completely unconvincing as an estimate of abundance' and Joseph Ogutu warned it could undermine confidence in fifty years of survey data. A correction to the paper was published in December 2025.
Observed — measured or witnessed, with the observation cited.
Subjects
- Blue Wildebeest (Connochaetes taurinus) · species · Tanzania; Kenya · not located
- Serengeti National Park · national park · Tanzania
- Serengeti Biodiversity Programme · research programme · Tanzania; United Kingdom · not located
Evidence
Verified — Every field is supported by a cited authoritative source. This is the standing of the weakest source, not an average.
AI-based satellite survey offers independent assessment of migratory wildebeest numbers in the Serengeti
An independent satellite-plus-AI count of 2022 and 2023 imagery returned fewer than 600,000 migratory wildebeest, a result the authors frame as complementary to aerial survey and which named Serengeti census specialists dispute
PNAS Nexus (Oxford University Press) · September 2025 (correction December 2025) · Verified
Duporge I., Wu Z., Xu Z., Gong P., Rubenstein D., Macdonald D.W., Sinclair A.R.E., Levin S., Lee S.J., Wang T. (2025) PNAS Nexus 4(9): pgaf264; correction PNAS Nexus 4(12): pgaf382. Expert criticism reported in Science news, 'Have half of wildebeests in the Serengeti disappeared?', science.org, September 2025.
Aerial Point Survey of Wildebeest in the Serengeti Ecosystem, 2023
The migratory wildebeest population was estimated at 1,366,109 animals in 2023 by manual triple-count aerial point survey
Tanzania Wildlife Research Institute (TAWIRI), with TANAPA, Frankfurt Zoological Society and KfW Development Bank · 2023 (report published April 2024) · Verified
TAWIRI, 'Aerial Point Survey of Wildebeest in the Serengeti Ecosystem 2023', published at https://www.tawiri.or.tz/wp-content/uploads/2024/04/Wildebeest-Census-2023-FinaL.pdf — estimate 1,366,109, margin ±231,741 (range 1,134,368–1,597,850)
Recorded on Blue Wildebeest (Connochaetes taurinus)
- Serengeti National Park established on land used by Maasai pastoralists
- Serengeti closed to residence; Ngorongoro Conservation Area created and Maasai evicted from the plains
- Rinderpest disappears from the Serengeti–Mara ecosystem
- The wildebeest population irrupts from roughly 250,000 to over a million
- The Mara–Loita migration collapses by about 81%
- Edge degradation squeezes wildlife into the ecosystem core
- Serengeti National Park inscribed on the UNESCO World Heritage List
- Drought kills roughly a quarter of the wildebeest population
- AI satellite survey returns fewer than 600,000, and is contested
- TAWIRI Aerial Point Survey estimates 1,366,109 wildebeest
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- TAWIRI Aerial Point Survey estimates 1,366,109 wildebeest · 2023
- Drought kills roughly a quarter of the wildebeest population · 1993–1994
- Serengeti National Park inscribed on the UNESCO World Heritage List · 1981
- The Mara–Loita migration collapses by about 81% · 1977–2016
- Edge degradation squeezes wildlife into the ecosystem core · c. 1977–2018 (40-year record)
- The wildebeest population irrupts from roughly 250,000 to over a million · 1963–1977
- Rinderpest disappears from the Serengeti–Mara ecosystem · c. 1960–1964
- Serengeti closed to residence; Ngorongoro Conservation Area created and Maasai evicted from the plains · 1959