The famous wildebeest migrations of East Africa are a significant ecological phenomenon and significant tourist safari attraction. However, many wildebeest populations are in serious decline across the region.
Their dispersal areas and migratory corridors are being lost due to high human population densities, increasing urbanization, expanding agriculture and fences. Their loss would contribute to biodiversity decline, and jeopardise tourism and other ecosystem services. Urgent efforts need to be made to protect wildebeest migratory corridors and dispersal areas to ensure these great migrations for the future.
Why is this issue important?
Once widespread, large-scale animal migrations are now rare, with many collapsing and others facing severe declines. For example, on the Great Plains of North America, the American bison once numbered as many as 30 million animals; today only few remnants remain due to over- hunting. Less than 200,000 Saiga antelope remained in Central Asia in 2000, down from over a million in 1980). Due to overhunting, habitat loss, and other human disturbances, large herds of Thomson’s gazelle and zebra that were migrating between Kenya’s Lake Nakuru-Elementaita region and Lake Baringo vanished at the beginning of the 20th century.
The extensive seasonal migrations of grazing herbivores are a well-known feature of the savannas of East Africa. The yearly migration of 1.3 million wildebeest, 0.6 million zebras, and Thomson’s gazelles in the Serengeti-Mara ecosystem is arguably the most well-known. Being the world’s largest and most species-diversified large mammal migration, its significance is immense. Due to its legendary significance for travelers and immense ecological value, Tanzania’s Serengeti National Park was inducted as a World Heritage Site.
Because the ecosystems of the East African savannas are so dynamic, animals rely on migration to follow resources that change both in space and time across the terrain. Because of this, populations that migrate have an advantage over populations that live there, and they can grow to extremely high abundances. In addition, migrants may relocate in order to reach breeding grounds, lower their risk of illness and predation, or improve their genetic well-being.
Migrations of wildebeests are significant from an ecological and economic standpoint. They offer several significant ecosystem services and are essential to the operation of the ecosystem. They also directly impact grassland food supplies, other wildlife species, and predator populations. The migrations of wildebeests are significant economically because they boost national economies by attracting tourists. According to KNBS (2013) and RoT (2011), Tanzania’s tourism industry brought in US$1.3 billion in 2011 and Kenyan GDP reached an estimated US$1.2 billion in 2012. An estimated US$550 million was made in Tanzania in 2008 from the northern safari circuit alone, which is primarily known for the Serengeti-Mara wildebeest migration. Some of the main tourist attractions in East Africa could be jeopardized by the loss of wildlife migrations or their habitats, which would have a big effect on national economies.
What are the findings?
Declining wildebeest in East Africa.
When migrating from protected areas to their seasonal habitats, which are frequently found in pastoral areas, wildebeest rely on migratory corridors and dispersal areas. Typically, migratory routes and dispersal zones traverse human-dominated environments where land use decisions are progressively more incompatible with the needs of wildlife. There may be sharp drops in the numbers of wildebeest as a result of the degradation or loss of these areas.
Due to incompatible land uses in their migratory corridors and dispersal areas, the white-bearded wildebeest, which can be found in Kenya and Tanzania as depicted in Figure 1, is experiencing significant declines in East Africa. This has happened as a result of their migratory movements being restricted by lost or blocked migratory corridors and dispersal areas. Many wildebeest populations have nearly collapsed as a result. The Serengeti-Mara population is the exception to this general pattern; after rinderpest was eradicated, its population increased sixfold between 1963 and 1977 before stabilising at its current level of about 1.3 million. Although their numbers are still much lower than those of the 1960s, the blue wildebeest are either stable or growing in southern Africa.
The most recent trends show that all four wildebeest populations in Kenya are drastically decreasing (Figure 2). Particularly, because of the expansion of agriculture, the yearly migration of wildebeest between the Maasai Mara National Reserve and the Loita Plains in the Mara ecosystem, which is located in Narok County, decreased by more than two-thirds, from roughly 113,000 in 1977 to 35,000 by 2009 and is still declining today. In the Athi-Kaputiei ecosystem, growing urbanization, fencing, settlements, mining, and other developments caused the wildebeest migration between the Nairobi National Park and the adjacent Athi-Kaputiei Plains to decline by more than 90%, from over 30,000 in 1978 to under 2,000 by 2011.
Due to growing agriculture and settlements obstructing their migratory corridors, the number of wildebeest migrating from Tanzania’s Tarangire National Park to the Simanjiro Plains fell by 88%, from 43,000 in 1988 to 5,000 in 2001.
Because of habitat loss in their dispersal areas or obstruction of migratory corridors, wildebeest are unable to reach their wet season ranges in any of these cases. When it comes to human impacts in their wet season ranges, wildebeest are particularly vulnerable. With the wet season ranges occurring almost entirely outside of protected areas on nearby communal or private lands, many protected areas in East Africa serve primarily to conserve the dry season habitat for migratory wildlife. Additionally, protected areas are often tiny and were not intended to preserve every aspect of a migratory species’ habitat.
Consequently, wildebeest have to travel outside of protected areas in order to get to their ranges during the wet season. They are under a lot of pressure here because of the growing human population, shifting land uses, and growing development.
Large migratory wildebeest populations were once able to be supported by protected areas because human population densities were low enough to permit the animals to travel outside of protected areas and return to their wet season ranges. But as the number of people living in the vicinity of protected areas increases, land use changes, and habitat loss worsen, this is getting harder and harder. According to Fynn and Bonyongo (2011), almost all of the world’s surviving large wildlife populations are found in unfragmented migratory systems today. Because it has endured in a largely intact ecosystem inside a network of protected areas that includes all the grazing habitats necessary to support a sizable migratory population, the Serengeti-Mara ecosystem migration, for instance, has been sustained. But there are now several threats facing this migration as well.
Threats to wildebeest migrations.
One of the biggest risks to wildlife migrations worldwide is the loss or fragmentation of habitats. Due to various land use activities that result in habitat loss and fragmentation in their wet season dispersal areas, wildebeest migrations in East Africa are declining. Wildebeest populations are declining as a result of these land use activities, which include farming, land subdivision, settlements, fencing, and other infrastructure. These activities also interfere with migratory movements.
Fences negatively affect wildlife populations and impede migratory routes. In addition to preventing poaching and preventing the competition for resources and the spread of disease between livestock and wildlife, fences also safeguard homes and crops. One of the primary reasons for the decline in the number of wildebeest in Kenya’s Athi-Kaputiei ecosystem is fencing, which obstructs and jeopardises migratory paths. Today, fences enclose more than 20% of the ecosystem, and they have blocked several migratory corridors that once connected the Nairobi National Park to the Athi-Kaputiei Plains. These days, during the dry season, very few wildebeest enter Nairobi National Park. Similarly, the Amboseli ecosystem and the Mara-Loita Plains’ wildebeest migrations are currently under threat from fencing, cultivation, and other developments.
According to Lesbarrères and Fahrig (2012), roads hinder migratory routes, kill wildlife in collisions, and reduce landscape connectivity. Roads can lead to new areas being developed and land uses that are incompatible with wildlife because of the increased access they provide. Developing a new road through the Serengeti National Park raises many of these issues. The Athi River-Namanga Road upgrade and the proposed Greater Southern Bypass Road along Nairobi National Park’s southern boundary pose a similar threat to the wildebeest migration in Kenya’s Athi-Kaputiei ecosystem.
Many migratory populations are at risk from poaching, especially as the number of people living in the vicinity of protected areas rises (Bolger et al., 2008; Harris et al., 2009). It is estimated that local bushmeat consumption causes between 70,000 and 129,000 wildebeest deaths annually in the Serengeti National Park. In Kenya’s Mara region, a high level of poaching is also associated with a decrease in the amount of wildlife. The population of wildebeests may decline if poaching in the Serengeti-Mara ecosystem increases any further.
The savannas of East Africa are facing an increasing threat to wildlife migrations due to climate change. According to the IPCC (2012), there will likely be more frequent and severe droughts and floods, which will alter vegetation growth and the availability of food for migrating animals. A severe drought in 2009 caused the wildebeest population in the Amboseli ecosystem to plummet by over 85% (MEMR, 2012). The population was at its lowest point in over 30 years by 2010, with only 3,000 animals remaining, compared to over 15,000 prior to the drought.
Man-made threats like habitat loss and fragmentation are likely to make it more difficult for migrants to adapt to changing climatic conditions. Migratory movements will be reduced as a result of land use change that eliminates migratory corridors and dispersal areas, which will also make it more difficult for migrants to adapt to the increasing climatic variability that is predicted as a result of global warming (Owen-Smith and Ogutu, 2012). Ogutu et al. (2013) demonstrate how the Athi-Kaputiei ecosystem is threatened by the compounding effects of human development and wider annual rainfall variation.
Protection measures.
Since the majority of migrants travel beyond protected areas, it is essential to involve local people and landowners in conservation initiatives by having them participate in benefit-sharing and wildlife management. The economic benefits of wildlife to local communities in the East African rangelands have been minimal, leaving them with little motivation to contribute to the protection of migrants, their dispersal areas, and migratory corridors.
Securing migratory corridors and wildlife dispersal areas is currently being attempted with the help of community conservancies, payments for ecosystem services, and other financial inducements. For instance, eight wildlife conservancies have been established in the Mara and provide landowners with annual land lease payments ranging from US$25 to US$40 per hectare (ha). These programs, which are funded by ecotourism businesses, are designed to give landowners a steady source of income while preserving the area for wildlife. As of now, they encompass more than 90,000 hectares, protecting crucial migratory routes and dispersal zones for wildebeest from the Loita Plains and the Serengeti.
The wildlife conservation lease programme, which is supported by several donors, pays participating landowners US$10 per hectare annually to keep their land open for livestock and wildlife in the wildebeest dispersal area of the Athi-Kaputiei ecosystem. By 2012, 24,200 hectares had been covered by this programme, which aims to protect wildlife migration corridors and drastically reduce fencing in this ecosystem. An alternative strategy involves utilizing environmental easements to safeguard privately owned land that borders Nairobi National Park, which may involve putting it under park administration (Watson et al., 2010; USAID, 2013). In order to sustainably manage wildlife dispersal areas alongside livestock grazing, settlements, and other land uses in the ecosystem, the community and other stakeholders recently developed the first community driven land use master plan (Nkedianye et al., 2009). Tour operators pay for ecosystem services in Tanzania’s Tarangire-Simanjiro ecosystem, protecting the migratory wildebeest’s dispersal area and other wildlife in the Simanjiro plains.
What are the implications for policy?
Implementing conservation plans outside of protected area boundaries is necessary to preserve migratory routes. With the support of community and private landowners, wildlife-friendly land uses, and dispersal areas and migratory corridors can be preserved for wildlife. Governments must create the right legal framework and enabling policies to support the kinds of migratory habitat protection initiatives that are already beginning to take shape. East African governments and the corresponding nations must cooperate to reduce threats to the migrations because it is a transboundary phenomenon.
Decisions about conservation and management need to be based on reliable scientific data regarding the where, when, and why of wildlife migrations. This entails mapping wildebeest ranges and movements, as well as having a solid grasp of the threats facing both migrants and their habitats, as well as the ecological factors that influence migration. In order to secure important wildlife areas, the governments of Tanzania and Kenya are already mapping migratory routes and wildlife corridors. In other projects, scientists are tagging wildebeest with collars to follow their travels and document them online in order to learn more about the effects of landscape fragmentation and climate change on wildebeest.
Predicting and addressing threats before the number of migrating animals is drastically decreased and the phenomenon of migration disappears is necessary for the conservation of migrations. Accordingly, organizations dedicated to conservation, like the Convention of Migratory Species, could be enlarged to include threatened or endangered migrations as well as those involving rare or endangered species. The Convention of Migratory Species, for example, works to conserve the migrations of species that are threatened with extinction.
Land use planning inside and outside of protected areas must be integrated in order to safeguard dispersal areas and migratory corridors. A more comprehensive conservation effort can be made by accounting for people, livestock, landscapes, wildlife and their migratory routes, and natural resources. In order to properly protect these vital areas, it is therefore necessary to collaborate with landowners and users to identify threats along migratory routes. Any action must be preceded by extensive consultation with governments, conservation organizations, communities, and landowners, among other stakeholders. In order to safeguard the surviving populations and restore their habitats, urgent, comprehensive, and decisive remedial action is required in response to East Africa’s sharply declining wildebeest populations. This will help ensure the sustainability of local livelihoods and increase their resistance to the increasingly severe droughts.
