Serengeti–Mara Rainfall Gradient

Assembled from 32 blocks · 3 evidence · 36 related

1. Story
2. A steep and persistent gradient in annual rainfall across the ecosystem, from roughly 400–500 mm a year on the south-eastern plains to as much as 1,200 mm a year in the north-west toward the Mara. It is produced by the rain shadow of the Ngorongoro Crater Highlands and the Meru–Kilimanjaro massif, which strip moisture from south-easterly winds coming off the Indian Ocean before they reach the plains. Boone, Thirgood and Hopcraft (2006) showed that wildebeest distribution can be modelled from rainfall and resulting new vegetation growth, which is the mechanism behind the claim that the migration follows rain and not a calendar.
3. Knowledge
4. Serengeti National Park
5. Serengeti–Mara Rainfall Gradient
6. Connections
7. Blue Wildebeest (Connochaetes taurinus)
8. Serengeti National Park
9. Drought kills roughly a quarter of the wildebeest population
10. Edge degradation squeezes wildlife into the ecosystem core
11. Blue Wildebeest (Connochaetes taurinus)
12. Maasai Mara National Reserve
13. Mara River
14. Serengeti–Mara Rainfall Gradient
15. Serengeti Biodiversity Programme
16. Rinderpest disappears from the Serengeti–Mara ecosystem
17. The wildebeest population irrupts from roughly 250,000 to over a million
18. Serengeti National Park inscribed on the UNESCO World Heritage List
19. Drought kills roughly a quarter of the wildebeest population
20. Edge degradation squeezes wildlife into the ecosystem core
21. The Mara River crossings
22. TAWIRI Aerial Point Survey estimates 1,366,109 wildebeest
23. AI satellite survey returns fewer than 600,000, and is contested
24. Ngorongoro Conservation Area
25. Maasai
26. Fortress conservation
27. Serengeti National Park established on land used by Maasai pastoralists
28. Serengeti closed to residence; Ngorongoro Conservation Area created and Maasai evicted from the plains
29. Evidence
30. Wildebeest distribution through the annual circuit can be reproduced from rainfall and the resulting flush of new vegetation growth, supporting rainfall as the proximate driver of movement
31. Continuous multi-decade monitoring and GPS telemetry establish the seasonal route, timing and drivers of the migratory circuit
32. Forty years of data show that land-use degradation at the ecosystem's edges has squeezed grazers into the protected core, reducing fire, soil carbon and nitrogen retention, and weakening the response of primary production to rainfall