Wednesday, 28 March 2012

On cattle in African protected areas

Typical pastoralist scene near Lake Eyasi
Talking about blog topics the other day, a friend asked me about the impact of goats and cattle on wildlife. And then over here someone else started a similar discussion on cattle, which collected a wealth of different ideas, so I thought it would be a good idea to collate all this information for a different audience over here. Increasingly, discussions about cattle come up when people are visiting areas that aren't National Parks - here in Tanzania many people are surprised to see cattle (and their Maasai herders) right in the Ngorongoro crater, as well as around the rest of the NCA. And increasingly (particularly in Kenya where land laws make it much easier, but also here in places like Manyara Ranch) conservancies are being set up where communities set aside land for both wildlife and pastoralist activities. The fact that organisations like the Northern Rangelands Trust are making a real success of this, combined with ongoing concerns about displaced people and human rights issues, has encouraged people to think seriously again about whether the strict 'no people' policy of many national parks in Africa might be relaxed, and recognising this a few years ago the International Conservation Union (IUCN) relaxed their national park category definition to allow management "To take into account the needs of indigenous people and local communities, including subsistence resource use, in so far as these will not adversely affect the primary management objective". So, what are the issues here, and what are the ecological arguments? In this post I'm going to deal with cattle, and leave the goats and sheep for a future occasion.

Cattle numbers in south and east Africa (data from FAO database).
Do we always need to move cattle away from wildlife areas?
To start, I think we need to be absolutely clear that the idea of an 'empty Africa' is a romantic, colonial-era myth: bear in mind that for at least 2 million year 'human' influences have been important in savannas (starting with fire and hunting), so the savanna plants and animals have evolved in a human-influenced landscape (those first hunters weren't hunting the same species we see today!). Now genetic, archaeological and anthropological evidence suggesting there have been cattle in sub-Saharan Africa for 9-10,000 years, including within all the major protected areas of Tanzania. As protected areas become increasingly isolated and the populations of animals are heavily influenced despite our best intentions, human management of the savanna is going to become ever more important, if we want to maintain healthy savanna ecosystems. Despite the history of cattle for 1000's of years, the numbers of cattle before the 1900s are not precisely know - evidence suggests around a 90% decline in numbers around 1900 associated with the great rinderpest epidemic and a gradual restocking since then, with a recent fairly rapid (last 10 years) increase in some countries/regions. It is probable the numbers are now higher than than pre-1900s. Despite this, increases are patchy and areas (such as NCAA) exist among the fast-growing areas where the population is actually declining.

As well as an increase in numbers, movements by nomadic pastoralists have been restricted - both from fences on commercial farms, by preventing them from using traditional grazing areas within protected areas and through policies designed and/or incidentally decreasing the nomadic lifestyle (compulsory schooling, forced settlement, provision of water points, etc.). In many pastoralist communities number of cattle is still the primary indicator of wealth, not quality of cattle. Even in communities where this perception is changing, there is a 'tragedy of the commons' that prevents effective herd reductions: if I'm a herder sharing grazing lands with others and I decide to reduce my herd size to get fatter animals, that has no impact if all the other herders around increase their cattle herds to eat the food my cows are no longer eating... All these things together mean that there are places within Africa where overgrazing  (by both cattle and goats) is a serious concern, cause permanent damage to the ecology of a system, creating open soils that are easily eroded by water and wind and are then surprisingly hard to revegetate. Nothing (cattle or wildlife) can survive in these areas once the annual grasses are grazed off each year. Pastoralists seeing uneaten grass in their traditional grazing lands within protected areas are either thoroughly fed up with conservation, or go ahead and graze anyway (or both), potentially resulting in unmanaged grazing within protected areas with cattle unprotected from predators and real risks of lion killings inside protected areas.

Meanwhile, wildlife numbers in the wider countryside have fallen dramatically, with noted declines around 1940s (leading to formation of the National Parks and Game Reserves by the colonial authorities) and in the last 30 years. Reasons for these declines in the literature focus on unsustainable hunting/poaching and (for the recent decline) an increase in agriculture in rangelands (with new cultural groups moving in who have a taste for bushmeat), with increased competition for grass from increasing cattle populations a relatively minor issue , despite the numbers of opinion pieces that discuss its possibility (eg here and here). The best example of this comes from studies around the Serengeti and Mara ecosystems which experienced similar population changes, similar change in land use, but different conservation policies massive declines in wildlife only experienced in and around the Mara. Population declines of lions/large carnivores are a special case where human impacts are direct and perhaps primarily attributable to pastoralist communities, many of whom traditionally do not consume much bushmeat, or otherwise hunt large mammals (though see here for a good list of cultural hunting practices and note that only one of the reviewed communities has no records of hunting.) Despite these declines, in East Africa many wildlife populations are still reliant at least part of the time on land outside of protected areas (and with no realistic chance of being joined into one) - even the Serengeti migration crosses largely unprotected land as it moves from the western corridor to the north in June/July. If population declines are to be halted and reversed, wildlife is going to have to live alongside people.

Maintaining a grazing lawn requires very heavy grazing, here at Grumeti
This loss of wildlife through poaching and the cutting of migration routes means that grass and browse that would have been consumed by wildlife populations is potentially under-utilised in some areas with an as yet unquantified cascading impact on other wildlife. To a certain degree, fire and grazing can compensate for one another in the creation of highly productive grazing lawns when correctly managed, but not entirely. For example, in Serengeti buffalo are one of the species whose population we know to be much reduced by poaching (though recovering in most areas, they've still got a long way to go). I have a hunch they are rather important in protecting riverine forests from fire, and it's their under-grazing that has caused the almost total loss of riverine forest on the Mara River - just upstream of the protected areas and just downstream where there are lots of cattle, there's healthy riverine forest. I'd love to see an experiment that allowed heavy but controlled grazing along the riversides when the grass is long - graze this down and you'll create a natural fire-break. Exactly as, I think, buffalo do where they're still in high numbers (they love riverine forest!). So there's a strong ecological argument in some places for increasing the grazing pressure, as undergrazing can be a problem, as well as overgrazing, though it's impacts are more subtle.

From here (shoats means sheep and goats)
So, what's to be done? I think a priority should be to help communities find some way to prevent the tragedy of the commons and encourage meaningful herd reductions in areas where overgrazing is a problem, and/or increase the mobility of these herds to allow land to recover (remember, pasture quality has declined within the Ngorongoro Conservation Area, despite a decline in grazing pressure, but because - I suspect - the herds are now more sedentary, and we know seasonal grazing has a very different impact to continuous grazing.).

We could deal with undergrazing by either cutting grass and moving it outside the reserve to feed cattle (as happens in some reserves in Natal, and some conservancies in Kenya), we could change the fire regime to (partially) compensate, or we could allow cattle into protected areas at certain times and in certain places and with certain conditions fixed (EG - you let a lion eat your cow whilst you're in the reserve and there's no chance you'll be allowed to make a retaliatory killing...)

In many way, to me, the most sensible option seems to be to make use of cattle productively - not only could this benefit conservation and reduce the undergrazing problem we have, but it would also make local communities much happier about the protected areas in the first place. The key to making it all happen, of course, lies in effective control. Effective community control on total herd size can eliminate the tragedy of the commons. Without it, there's no way letting people with cattle inside protected areas will ever be a good idea. It would also need to be thought about clearly and monitored carefully, with local conditions dictating the activities. And we must always remember that there's an imbalance here: whilst buffalo and cattle are ecologically rather similar and we could use cattle to do a buffalo's job, when there's a shortage of resources ultimately it's cattle, with their human herders to help them, that will win out. So my feeling is that the wisest use of cattle in protected areas is likely to be seasonal: when there's a super-abundance of food (potentially to the degree that smaller grazers can't utilise the long grass), that's the time to make use of cattle. That also suits because the rainy season is also wildebeest calving season, and the only time wildlife really can win out over cattle is when they're calving, thanks to risks of disease transmission at this time.

Anyway, these are just my thoughts and I know other will have different (and possibly very strong!) views on this issue. (And if you don't come from an African conservation perspective I think you might be surprised to hear how heated the debate gets! In Europe cattle and sheep are very much part of the conservation picture...) I'd love to hear them! As I've often said when doing training, these are contentious issues and I really don't mind what you decide in the end, as long as you understand the issue and can discuss them in an informed manner!

Main references:
ResearchBlogging.orgHanotte, O. (2002). African Pastoralism: Genetic Imprints of Origins and Migrations Science, 296 (5566), 336-339 DOI: 10.1126/science.1069878

Homewood, K. (2001). From the Cover: Long-term changes in Serengeti-Mara wildebeest and land cover: Pastoralism, population, or policies? Proceedings of the National Academy of Sciences, 98 (22), 12544-12549 DOI: 10.1073/pnas.221053998

Prins, H. (1992). The Pastoral Road to Extinction: Competition Between Wildlife and Traditional Pastoralism in East Africa Environmental Conservation, 19 (02) DOI: 10.1017/S0376892900030587 

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