What is the influence of climate change on Tanzanian protected areas?

Pangani Longclaw Macronyx aurantiigula is perhaps the best example
of a species extending west, having colonised Serengeti recently.

It's been a long time since I posted anything here - sorry! I have another common birds post in progress, but just keep failing to finish it off. In the mean time I thought I'd talk about one of my own papers that came out a few weeks ago that explores how Tanzanian bird distributions are changing (sorry, it's pay to view, but if you want a copy email me and I'll send it!). This analysis is a fairly major result of my collaboration with the Tanzania Bird Atlas and represents the combined efforts of a very large number of people, volunteers and professionals, who contribute invaluable data to Neil and Liz Baker - I know some of you read this, so firstly, thank you, and secondly, I hope you appreciate seeing how we can use these records to do interesting and (I hope!) useful research.

Indian house crows and invasive aliens

Indian House Crow, not the prettiest... Thanks to Dick Daniels

There are very few birds I don't like to see, but today's common bird is an exception - the Indian House Crow, Corvus splendens. Actually, that's probably slightly untrue, as I have been to India and I was perfectly happy to see the species there. In East Africa, however, this is not a species I'm ever happy to see. Not because there aren't interesting things to say about it, of course, but because it really belongs in India and seems to cause a number of problems elsewhere.

First though, identification is fairly simple: the house crow is a medium-large all black and grey bird, usually found in flocks in towns all along the coast and, in some areas, invading inland too. It is very loud, with a persistent "Carr, Carr, Carr" call that is the constant sound of Dar es Salaam bird life... There are few confusion species in East Africa, the only other common species of crow being the black and white Pied Crow, which often hangs about with the house crow.

How to protect lions?

Lions: just big kitties really!

There have been a couple of lion stories in the news in the last week or two, and enough interest in them that I felt compelled to write something. First there was a paper by Craig Packer and many coauthors about lion populations in Africa, their current declines, and the possible role of fencing in protecting them. Then, shortly after, there was a letter in the New York Times by Tanzania's own Director of Wildlife, asking the US government not to list the lion as endangered, as lion hunting is crucial to their conservation in Tanzania.

More on management of protected areas: the human dimensions.

Public relations are a huge part of conservation work

In the previous post I described two of the ten lessons that we, a bunch of conservation managers and researchers from eastern and southern Africa identified at a workshop in Serengeti. I started with the big lessons on making sure you start with boundaries that make ecological sense - and what can happen particularly to migrations if that's not done. There's more to learn on that score too, but I'll skip to one of the most important lessons we identified, that will come as no surprise to anyone working in the field: don't neglect public relations!

On managing protected areas...

Spot the scientists! Prizes for anyone who can name at least 4...

In  a very rare burst of finishing things of, I've managed to submit two papers this week (wow!). One is on climate impacts and I'll blog about it in time, the other is something I've been working on for a some time that reports the deliberations from a workshop that I was invited to 18 months ago now, at Sasakwa Lodge in the Grumeti Game Reserve. This was a fascinating experience, and not only because it's the only way the likes of me will ever get to stay in Paul Tudor Jones' house and be looked after like a real guest! We brought together several senior researchers and conservation practitioners from Tanzania and Southern Africa, to see what would happen. And what did happen (as well as the lodge running out of whisky), was an attempt to identify the ten most important lessons for conservation that could be learnt from the mistakes of southern Africa. As they say, it's a wise man who learns from his mistakes, but it's an even wiser one who learns from the mistakes of others! So, given that the population pressures in east Africa are now similar to those experienced in southern Africa when lots of conservation interventions started to happen down there, we thought it would be a good time to see what we could learn.

African Vulture Declines

I saw this hooded vulture in Tarangire this weekend, so they are still around!

I've spent a bit of time over the last few days analysing some of the data from the Tanzania Bird Atlas project on vulture declines in advance of a workshop happening soon in the Maasai Mara. The Asian vulture decline is quite possibly the fastest decline in any bird species ever recorded, with more than 95% of the Indian population of Oriental White-backed Vultures dying between 1988 and 1999, from one of the commonest large raptors in the world to one of the rarest. It's now well know that the cause of that decline with the veterinary use of a drug called Diclofenac which, happily, isn't in quite the same usage here in Africa - sick o dying cows tend to be eaten here, not treated with drugs and then left for the vultures. But although the declines haven't been as steep and there are still plenty of vultures in places here in East Africa, there's still a problem.

Revising climate impacts on African vertebrates

A few weeks ago I wrote a piece on climate change and African vertebrates. As I usually do, and especially in this case as Raquel had pointed the paper out to me, I let her know that I'd written something and asked her opinion. After quite a few emails back and forth we confirmed that I'd misunderstood a figure in the paper that I'd thought was the crux of the matter, but it turns out to have been not as useful at all.In light of these discussions, Raquel and colleagues have now produced an addendum to their paper that contains the figure I thought I was looking at and, although I still have some issues with the work, it makes much more sense to me now! In the interests of getting all this information out there, as well as my pointing out the mistakes in the original post and Raquel posting a comment there, I thought her ideas were valuable enough to reprint in full from the comment as a new post, with some more discussion here. So, here's what she has to say:

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.

Lewa Downs wildlife corridor really works!

As regular readers will have realised, I'm something of a sceptic about most things, and one of the things that I've been pretty sceptical about in the past is wildlife corridors. They sound like a great idea: wild spaces are increasingly fragmented (even here in East Africa), and as that process continues populations of plants and animals within these areas will become increasingly isolated from one another. Isolated and small populations are more likely to go extinct than large, well connected populations for a number of reasons ranging from inbreeding - in small populations you're rather more likely to have to mate with a brother or sister than in a large population, which can have serious genetic costs, to simply the risk of extreme events wiping everything out. So connecting those fragments with corridors along which animals can pass seems like a really good idea. Tiny experiments using micro-ecosystems where no-one cares if you isolate populations or connect them seemed to suggest that there might be something in this idea, and all of a sudden conservation corridors were high on the agenda.

Migrant bird population declines, an African perspective

Willow warbler singing in Africa - 10g but probably headed to eastern Siberia...

March is the month when northward migration of songbirds gets underway in East Africa, so this weekend I was excited to be out west of Arusha with friends and to find stacks of migrants already on the move. Driving in I noticed some really smart looking wheatears (both pied, and the very impressive northern wheatear, though many of them have already set off on their mammoth treck - perhaps as far as Alaska). But the highlight for me was the bushes alive with warblers on Saturday morning. I saw flocks of Willow Warblers, Olivaceous Warblers, Common Whitethroats and even little groups of Barred Warblers, usually a very scarce migrant around here. Some of them were even singing, in anticipation of starting breeding in a few more weeks when they get back to Europe! Having a managed a few photos I thought it the ideal opportunity to talk about bird migration.

Barred warblers are always a treat to see: headed to eastern Europe.

All these birds have been rather scarce until now, this season, and many of us have been wondering where they've got to - usually Willow Warblers and Olivaceous Warblers are one of the commonest birds in the bush from November to March, this year there have hardly been any. It's a question that will be familiar to many readers from Europe - where have the migrant birds gone? Research has suggested over the last few years that in Europe at least, migrant birds are declining faster than resident species, a change that has been attributed mainly to climate change. A number of theories have been put forward to explain why migrant birds may fare worse than resident species from the impacts of climate change - from them simply missing the peak spring food availability by arriving to late in Europe as springs get warmer (and therefore earlier), to direct effects of drought or land-use change in Africa. A recent paper (sorry, not free) has attempted to look into some of these likely causes using data on breeding population changes in the UK, and it serves as a nice bit of background to some of the remarkable things that birds do when they set off on their amazing migrations.

Threats and opportunities of the bushmeat trade

Snared giraffe, Serengeti NP Jan 2011. A major target right now

Following my post a while back about Dennis Rentsch's work on the bushmeat trade around Serengeti, Matt asked me to cover this issue in a bit more depth. (Though if you want to see how it's possible to have a sustainable harvest of around 100,000 wildebeest per year from Serengeti, with a net value of $2.5-$8.5 Million per year check the original post here!) And there've been a number of interesting papers recently that have started to fill in some details. It's not a subject I've much experience of, so I'm skimming the surface a bit, but I think it might at least highlight some of the issues involved.

We'll start with the caveats. Understanding the bushmeat trade is tricky - in most places it's illegal, and people aren't always going to talk freely. And if they do talk, there's a good chance they won't tell you the truth either - they might either say they do less hunting than they really do to play down the impact, or they might go down the macho route and tell you they're excellent hunters and never come back without a pile of buffalo, etc... Dennis's work took an alternative strategy, instead of asking the poachers to tell him what they hunted, asking the villagers to tell him how much bushmeat they consumed and working back to the harvest that way. Others have worked on data using poacher arrests, viewing this as an index of poaching activity - though there's no way to tell what proportion of poachers get away with it (what poacher, when arrested, will really tell you how often they've been poaching before and not been caught?!). The only comparison between these three methods is Dennis' and that suggests that measuring consumption gives a poaching pressure that parallels that from arrest records, but neither of these fit with pressure as assessed by poacher interviews. That suggests to me that Dennis' work is probably the most accurate, but he's not yet published these studies, so for now you can only read about it here. The vast majority of other work is based on poacher surveys, and we also know that when you compare what poachers say the meat is with what the DNA tells you, you get remarkably little agreement too.All of this suggests to me that we need to take the research based on poacher surveys with a large pinch of salt. So, with that in mind,  I'm going to focus more on the declines that are reported to be associated with bushmeat, rather than the more poacher-based surveys.

On introducing elephants to Australia...

Sometimes scientists suggest the most absurd things. In the news last week (with thanks to an Australian friend for tipping me off) was a paper published in the prestigious journal Nature that suggested in the text and headline that Australia should introduce elephants to control an invasive grass that originally came from Africa: Gamba grass, Andropogon guyanus. The author made a number of sound observations: Australia (like too much of the world) is riddled with invasive species, has suffered a massive extinction of it's native mammal population and has had some pretty nasty wildfires in the last few years. But how you get from those observations to suggesting elephants (and even rhinos) should be introduced to the savannas of Australia is a story worth looking into.

Climate change and African vertebrates

Last year I spent a very happy evening in Cape Town enjoying some of the local specialities with a colleague and a visiting student. Or at least, that's what I thought - poor Raquel now tells me I was giving her a hard time... Still, good practice for her eventual defence of her thesis I hope. Anyway, she pointed me in the direction of the paper she was writing at the time that's now out and attempts to describe what's going to happen to some 2723 species of African vertebrates as the climate changes over the next several decades. Now, despite climate change being a huge conservation issue and one of my main research interests (and climate/weather being one of my 10 things to talk about), we've not talked much about it here on the blog before, so the chance to discuss what might happen to 2723 species across the continent as a whole is an ideal opportunity to start!

TAWIRI conference discussions continued: Ruaha River

Wetlands, like Silale Swamp in Tarangire, are vital for feeding rivers

Returning to the TAWIRI conference back in December that I posted a bit about already, the other talk that set me thinking about economics of conservation was a fascinating talk by Eric Wolanski about ecohydrology. About what, I hear you ask?! Ecohydrology, the study of the interactions between water (hydrology) and ecosystems. Now it occurred to me that we've not done a post specifically about wetlands yet, which is a bit of a major ommission, given their importance in savannah ecosystems. We'll have to rectify that in time, but for now we're going to plunge straight into some important stuff.

Flows in the Mara River have been disrupted by deforestation in the Mau Forest

As we all know, the life-blood of a savannah ecosystem is its permanent water source(s). As we've talked about in our Serengeti Story, the Mara River is the only important permanent water source in the Serengeti Mara ecosystem, and the animals move a long way to get there. Tarangire has the Tarangire River. Ruaha has the Great Ruaha River, etc. What makes these rivers permanent and other rivers in the savannah only seasonal is that they're fed by sources that capture the rain in the wet season and slowly release it during the dry season, whilst sand rivers tend to just be rain fed. The Mara is fed by the Mau Forest in Kenya, Tarangire River by Silale Swamp, and the Great Ruaha by a series of wetlands, including those of the Usangu Flats. Meddle with these 'sponges' and you can get in all sorts of trouble with your permanent water sources.

Birds and other wildlife also love wetlands like Silale! Sep 2011

Eric told a fairly simple story, but a fascinating one none the less (especially when you start doing the sums that I've been looking at). If you have vegetation covering a waterbody, he said, the water loss through evaporation and transpiration (plant breathing) is about 50% of the evaporation you have from open water. Somore water flows from vegetated wetlands into rivers than from ones taht have lost their vegetation through excessive grazing. Which is exactly what had happened during the 1990s and 2000s on the Usangu flats, above Ruaha. Much of the water that flows from Usangu at the end of the wet season is the water that subsequently fills Mtera Dam, so keeping the water flowing - as well as providing a vital resource for the wildlife of Ruaha National Park - is pretty important for electricity generation in Tanzania! Uncontrolled (but illegal) immigration had allowed hundreds of people with an estimated 300,000 cattle to occupy the Usangu Game Reserve (as it was), and the cattle ate all the vegetation over the wetland. As a consequence the evaporation rates increased and less water flowed from Usangu into the Great Ruaha. In 2006 the government decided to evict these people and incorporate the Usangu Game Reserve into Ruaha National Park (in so doing creating the largest National Park in Africa), hoping to restore water flows, though among serious concerns about human rights. And Eric was able to watch the consequences in the flow rates through the Usangu flats and into the Great Ruaha river. Amazingly, this operation alone has resulted in the Ruaha river flowing for an extra month. Now that result is a great success for conservation, but it's not the end of the story by any means and I did some quick back of an envelope calculations of my own that are pretty staggering, but before we go there let me post a few caveats - firstly, I'm not a hydrologist and I'm just reading a few things quickly, I'm not guaranteeing these figures in any way. Also, as I've not always found the exact figures I've tended to err on the side of caution - for example, I've found statements that show dry season flow is unimportant to Mtera water levels (as you'd imagine), but that the dam mostly fills when the Usangu wetlands are flowing full rate at the end of the wet season, but I've not got the relative figures for this so I've assumed that the flow operates continuously - which should underestimate the importance of Usangu. Still, here are some interesting numbers...

Early in 2011 the IMF downgraded it's forecasts for growth in the Tanzanian economy from 7.5% to 6%, due to the costs imposed by TANESCO power cuts (up to 16hrs per day in much of the country!). Tanzanian GDP in 2010 was abour $23 Billion, so the cost to Tanzania of the powercuts, according to the IMF, is $345M. [Interestingly, that GDP is a tiny bit more than George Soros and family have tucked away, is similarly a tiny bit more than the value of the treasure recently discovered in the vaults of an Indian temple and is not even half the annual turnover of GlaxoSmithKlein!] Most of these power cuts were caused by low water levels in dams preventing power generation - Mtera dam (fed by Usangu through the Great Ruaha) feeds two power stations, Mtera and Kidatu, producing between then 284MW of power, which is about 40% of Tanzania's total capacity of 769MW (Thanks TANESCO for these figures). I've not found how many months the stations were going for, but I did discover that for the last few years the Ruaha has flowed for only 9 months, so let's assume it's similar. Now if we assume that 40% of the cost of the blackouts is caused by Mtera not producing (actually, I'm sure it's much higher since it's mainly the Hydro part of the production that's failing, but that's the proportion of overall capacity sourced by Mtera and will give a conservative estimate), those thee months of non-flow each cost the Tanzanian economy $46M. So the government's action to remove cattle, by providing an extra month's flow from Usangu, might well ahve saved about $46M per year. Not a bad investment, I think, even if they had paid the going rate of $150 per cattle the $45M required would have been paid off in one year and as it was many of these cattle moved elsewhere where they caused less damage to sensitive wetland habitats.

Now the final question you'll be asking, I guess, is what about the remaining 3 months of no-flow? How can we get that back? Well Eric and colleagues estimated that if the rice farms that are the other major water user returned only 25% of their water, there's be no problem at all. And I've just done a quick check and found that the estimated cost of completely closing the rice farming industry in this area would cost the national economy 'only' $15.9M per year. If that's what it takes to keep Mtera flowing, it doesn't seem a particularly hard decision for me, and think of the wildlife benefits too!

Anyway, I hope those figures are of some interest - it just goes to show that conservation really can be a 'win, win' option, even when hard decisions need to be made. Let's just hope it doesn't take too long before someone sees sense here - good luck to those people and organisations trying to build awareness of these issues!

TAWIRI Conference discussions

I've spent most of this week at the Tanzania Wildlife Research Institute (TAWIRI) conference here in Arusha. This is an event that happens every two years and involves a very high proportion of researchers active across Tanzania, so it's always a good place to hear about interesting things going on in these areas. I thought I'd give a few of my highlights today. The two talks that most exicted me were from two different aspects of ecology - one by Dr. Grant Hopcraft on the Serengeti and how climate change might impact wildlife there, the other also related to Serengeti, but this time by Dr. Dennis Rentsch from Frankfurt Zoological Society on the economics of the bushmeat industry. I know both of these folk fairly well, so was able to press them for lots of extra information about both talks, and what I'm going to descibe here represents both their presentations and some of the other stuff we talked about - I hope they don't mind me putting this information out before it's all polished and published!

Wildebeest and zebra migrating through Grumeti Reserves, Feb 2010

Grant knows rather a lot about Serengeti and, in particular, the herbivores of the system. His work has focussed on how nutrition impacts herbivores and his talk fitted well into the overall theme of the conference on climate change, by asking how climate change will affect the nutrient content of the grasses and how this might impact the animals that feed on them. You might think it's crazy to suggest that climate change impacts grass quality (i.e. nutrient content), but actually it can have some pretty profound impacts indeed. Grass growing in high rainfall areas gets very tall very quickly, but also tends to be poor in nutrients - it might be that the grass can only collect the same amount of nutrient from it's roots, but in wet years it grows faster, so there's less nutrient per leaf than in dry years when the plants can't grow as much and pack all the nurients into a smaller volume. So more rain means lower quality grass, but more of it, less rain would mean less, but higher quality grass. In fact, lots of people showed plots of rainfall in Serengeti and demonstrated that the area is getting wetter (though I also suspect there might be shifts in the dry season length which could be even more significant, but no-one really talked about that), so we should be seeing more, lower quality grass. What is the consequence of this? Well, according to Grant, perhaps it means different things for different species, since all the herbivores prefer slightly different combinations of nutrient quality and grass quantity. In particular, hind-gut fermenters like zebra are happy with lots of relatively low quality food, whilst wildebeest are typically selective ruminants and need higher quality grass. Now, Wildebeest in Serengeti are food limited, not predation limited or anything else, so a decline in food quality might be bad for them - but they are, of course, interested in quantity too, particularly during the dry season when any rain is going to provide grazing which is clearly better than no rain at all. So a wetter Serengeti, if it impacts the dry season too, is probably going to mean more food at this crucial dry-season food shortage period, and we can expect that even in a wetter dry season the rain will still be scarce, so the grass will be relatively nutritious. So on the one hand poorer-quality forage during the wet season might be bad news, but more grass in the dry season is certainly going to be good news - which effect wins out isn't yet clear. My money will be on the dry season effects, but we'll wait to see! On the other hand, it seems pretty unambiguously clear that a wetter Serengeti will be good news for zebra, provided again that the dry season remains at least a bit wet too. So more zebra will always be good - though how that will affect everything else is also tricky to forsee. Does more zebra mean better facilitation for the wildebeest? Or might there be more competition? Who knows, as usual, more research needed (and if you want to fund Grant on his next project, do let him know - he's searching for money right now!).

The migration reaches Seronera, Nov 2010. Don't get eaten!

Spot the snare: many animals are poached in Serengeti. Moru Jan 2011

Meanwhile Dennis has been working on bushmeat trade on the western side of Serengeti for many years now. His approach to studying what is, after all, an illegal activity has been to deal not with the hard end in the park of finding and apprehending poachers and trying to get them to tell him how many animals they hunt (they're very unlikely to give an honest answer in such circumstances!). Instead he's focussed mainly on trying to work out how much bushmeat is being consumed in the villages around the Serengeti by asking them about the various protein sources they eat during the week. Although there might still be some resistance to tell the absolute truth in this context, it's likely his numbers are underestimates of the full impact of the harvest (especially as it doesn't include any of the meat that gets exported from the region commercially). Underestimates they might be, but the numbers are still staggering. In the villages surveyed, the average number of meals of wildebeest eaten per family per week was 2.4. Obviously that goes up during the period when the wildebeest are migrating through the particular village, and down when they're far away, but 2.4 meals per week is the average for the villages immediately around Serengeti NP. And knowing the number of households in each village, plus the number of villages Dennis estimates that somewhere between 90,000 and 100,000 wildebeest are harvested (illegally) from Serengeti each year. To put that into context, it's equivelant to a harvest greater than the entire wildebeest population of South Africa each year!

At between 500 and 1500TSh / kg (depending on seasonal availablity), and assuming a conservative 100kg of meat per animal that gives a a total market value of $2.5 - $8.5 Million per year. Compare that to TANAPA income from Serengeti gate fees 10 years ago (the latest I can find online) at about $5.23 Million, and we're talking the same size economy. (Bear in mind that these TANAPA fees are used throughout the national park system to subsidise less well visited parks, so Serengeti NP actually has an opperating budget of only around $2Million per year.) That's a pretty remarkable figure on it's own, but Dennis went on to talk about how consumption is related to price of other meat in the area - if the price of beef goes up, more wildebeest is eaten. Which suggests that it might be possible to reduce the amount of wildebeest eaten, if you bring the price of beef down. Now unfortunately I wasn't quick enough to get all the figures off Dennis's slide to do the calculation here, but I think I'm right in saying that if you want, say to halve the wildebeest harvest, his figures suggest you need to bring the price of beef down by about 3 times as much - so 50% of 50% of 50%, which is an 87.5% reduction in price. That's probably going to be tricky to achieve, unless you fill Serengeti with cattle, which is hardly going to help! So you're rather stuck there. Instead, the only effective solution is to make the wildebeest more expensive - and Dennis suggested you can do that either by giving poachers alternative employment and dry up the supply of meat, or by even more strictly enforcing the regulations within the park. But bear in mind that this is a sustainable harvest - there's no impact of this level of poaching on the wildebeest population overall. The problem is the bycatch - people want to trap common wildebeest, but instead their snares catch resident game sometimes and have had a missive impact. So instead of strictly enforcing current regulations, perhaps TANAPA should be looking at ways to encourage sustainable use and minimse the negative off-take. Perhaps making a few million $$ in the process. What do you think? Should we go this way? Or how should we feed these people?

Conference insights

A couple of weeks ago I enjoyed spending the week at a combined meeting of the Association for Tropical Biology and Conservation and the Society for Conservation Biology's African chapter, here in Arusha. Now Arusha is not particularly a hub of scientific activity, so if you're an academic, far from colleagues any conference is going to be worth attending, and an international meeting of these two groups is probably a one-off opportunity (in fact, it's the first time ever the ATBC has met in Africa, let along Tanzania. One could wonder where the tropics really are...). So, for four days I was eyeball deep in science once more. Along side the talks, I was organising a workshop on fire and burning Serengeti, then last week I was teaching a course associated with the conference, so I decided to give talking at the meeting a miss this time (not to mention the fact that the abstract deadline once again caught me unawares...), and was able to sit and enjoy lots of interesting things. I'd have blogged about the highlights whilst they were happening, had I not been too busy with other things in the evenings. But now I've got time and am looking back over the notes, thinking I might summarise a couple of interesting facts I learnt today, and maybe some more tomorrow.

So. A talk by Damian Bell from the Honeyguide Foundation (about which all Asilia guides should already know, of course), was the first that had me reaching for my notebook. He had to hand some useful facts directly relevant to conservation, one of the 10 things I think worth talking about when there aren't any lions. Most striking to me were some figures from TANAPA's annual report (from 2007, as it happens, but I doubt they've changed much since then). TANAPA - the Tanzania National Park authority that manages all of the National Parks in Tanzania - had revenue of 69billion TSh (that was about $42,000,000 US) in 2007. This will almost all come from gate fees and bed fees - not a bad income. Of that, of course, TANAPA pay 50% in tax back to the government, but the bit that struck me was the fact that only 1.8% of the income in spent in local community related projects around the protected areas. It seems self-evident that if local populations don't see some benefit from conservation - and financial benefits are surely the most direct - then they're no going to be particularly supporting of the National Park when things are under pressure. So to see just 1.8% heading back to the communities seems extraordinarily short-sighted.

It's not good on village land either - 60% of revenues generated by villages for wildlife related things goes straight to Wildlife Division, leaving only 40% for the villagers. And things are only a little better for Wildlife Management Areas - 60% of the revenue generated by a WMA stays local (40% goes to Wildlife Division), but from this the WMA has to fund all the protection and visitor access things, so it's still not clear how much will actually be felt by local villagers.

Damian also had some interesting figures on quite how much benfit the tourism industry can generate aside from conservation fees - Grumeti Reserves are currently spending $30,000 on fruit and vegetables to local farmers each month. This sort of tourism-related revenue clearly offers massive benefits, well over and above what could come from TANAPAs 1.8% investment. So it's clear that tourism can play a vital role in financing conservation - without it, there's no way we'd have the parks we do today. But, of course, tourism also needs to be controlled if its not to cause more problems than it solves. Though that's a story for another day...

The next talk that had me scribbing was the final answers to his PhD research into the Wildebeest migration into and out of Tarangire National park, by Dr Tom Morrison. Tom started by reporting the staggering decline in Wildebeest numbers from this ecosystem - between 1990 and 2000 the numbers dropped from 43,000 to only just over 5,000. Today Tom tells me there are between 2500 and 5000 remaining. Of course this is nothing to the numbers of wildebeest back in the 1960 when we know the decline began. Tom's focus has been trying to determine where, exactly, the migrant wildlbeest go and how much movement between calving areas there are. We knew that animals from Tarangire go to two main areas - via Manyara Ranch up to the nutrient rich grasslands on the way to Lake Natron, and out east of the park to the Simanjiro Plains. It has also been suggested that animals might move to Lake Manyara National Park too, so he went there for good measure. Tom didn't want to just know where one or two animals went, he wanted to know them all. And he wanted to know if the same animal might switch from place to place each year, or if they always went to the same area. So he couldn't got for the most expensive option of satellite tracking all the animals - instead he decided to take photos.

Wildebeest showing their stripes whilst on the move at Mwiba Game Rance, Feb 2011.

Just like zebra stripes, wildebeest stripes on their flanks are individually recognisable. So Tom and his colleagues made a clever computer program that will search through thousands of photos and match pictures of animals with the same stripes. All he then needed to do was take lots of pictures in Tarangire and all the breeding areas over several years and join the dots. Five years and 9000 photos later, he's managed to trace movements of 900 animals - that's a significant proportion of all the animals out there - and he discovered some interesting things. Firstly (and probably most importantly) the Tarangire population is a single population - about 18% of animals did switch calving grounds between years. Animals calving in Simanjiro one year may well calve up at Natron next year. Next he confirmed that the animals in Manyara National Park are more or less resident, living there all year around, with very little interchange with the animals calving near Natron.  But the result that seems most surprising to me is that the only thing that really determined whether or not an animal would switch calving grounds one year to another, was if it calved successfully. If I'd been asked to guess before hand, I'd suggest that an animal that calved successfully one year would want to return to the same place to calve again the next year, whereas an animal that failed might decide to try somewhere else next year - but Tom showed that the opposite occurred and more switches happen after successful calving than after unsuccessful calving. Very strange - any ideas anyone? Disease? Who knows... He also showed that successful calving has a cost to females, with them having a lower survival in years when they calve - that wouldn't be any surprise to anyone who brings up small children if they had to live in an area with lots of lions and constant distractions too!

Anyway, very interesting things, I'm sure you'll agree! Hopefully something to pass on to visitors too.