Sunday, August 21, 2011
Soon the fastest running mammal will be roaming
. This will be a significant step in returning the region to a balanced system. The grazers and browsers continue to build the lower part of the Gorongosa food pyramid for the soon to be released carnivores. Gorongosa National Park
How did this animal become so fast? It is good question to ask a beginning biology class. The question prompts a variety of misconceptions around evolution by natural selection. "The cheetahs learned to run faster over time" one student might respond. Or "They ran faster because they needed to catch the small fast antelope." Genetic variation is usually the concept that is overlooked. The fact that some ancestral cheetahs might have had the ability to run slightly faster than others. Then there is the adaptation and the fact that not all survive to reproduce. Yes, the speed enhances the ability to get food and survive. Finally, the genetic link to future cheetahs. Those enhanced survivors pass on their genes for speed. Of course it helps to conceptualize the timescale of millions of years and the fact that this increase in speed is not happening over several generations but hundreds of thousands of generations. Hence, the cheetah is a fine model for introducing natural selection. It is also a fine specimen for reintroducing top predators into this recovering ecosystem in order to bring it back to its previous balance.
The cheetahs we observed in the enclosures near Explore Gorongosa had been transported from
weeks prior. There were two holding pens dividing the animals. Two brothers were in the larger enclosure and were clearly very compatible. We observed them sleeping together, laying on top of each other, and frolicking together. This is common between male cheetahs. Males which are brought together from distant areas will often develop tight bonds together. Brothers will typically remain together for their entire life. South Africa
The female cheetahs are a different story. The one we observed was clearly more aggressive and showed us her well developed teeth on our first encounter. She then slowly strolled across her enclosure with a beautiful smooth gait with raised shoulders going for cover after giving us her warning. Good to see the wild side - it is comforting for the pending release. Best of luck to the local African hares, rodents and young impala.
Friday, August 5, 2011
The morning light on the way to Mt. Gorongosa added a new dimension to the trees. Every trip in the helicopter gives new perspective on the landscape. The shadows in morning made each tree appear more prominent in the forest.
We were delayed a little coming back to Chitengo due to taking the nets down along the forest edge. Upon landing back at camp, Bob was there with his Land Rover to pick me up at the helo landing area. He was with Candida Pinto a well-known Portuguese television news journalist. She is here by way of Libya, Egypt and some other places to do a story on Gorongosa for Portuguese and Mozambique television.
The day ended at the Hippo House, on the edge of Lake Urema. This is an old restaurant and bar structure from the glory days of Gorongosa. It sits on the edge of Lake Urema and is an incredible spot for birding. On arriving to the area I watched a Black-headed Heron swallow a 14” snake.
We used the site to shoot Ed for a couple of pieces for Life on Earth. Beautiful scene on the marsh. Interviews were also conducted with Mark Stahlmans and Greg Carr.
Just another day in the Park.
You can never have enough cheetahs. The park will be introducing three imported cheetahs soon, after an acclimation period in the sanctuary area. Bailey and I worked up a scheme for improving the cheetah situation. One thing we have a ton of here are warthogs. The population of jungle pork is hugely out of balance. So we proposed to Greg that we could pile warthogs in a fleet of buses and head off to where the cheetahs are in southern Africa. Then we spread out warthogs behind us on the way home to create a population density gradient of warthogs that the cheetahs will follow to Gorongosa. The warthogs seem to be a cheerful and unfocussed bunch and I don't think we would need to make up an elaborate story for them. Then they would do what they are supposed to do, which is give it up for the cheetahs.
Grimly, it turns out that cheetahs would rather tangle with just about any smaller four-footer before they try a warthog. When the warthogs came plowing and schmuffling the cheetahs would go scampering back to Zimbabwe. So Bailey and I are back at the drawing board in the endowed chair we share at the Institute for Impractical Ecologists, which is what we shall call our second-row seat on the safari truck.
There's an old story that if a biochemist wanted to figure out a locomotive, step one would be to blow it to smitherinos. The reductionist approach works pretty well for cells. Pulverize, separate, and do experiments to figure out which pieces fit together and how they help the metabolism of the cell hang together.
Gorongosa got pulverized during the civil war. Rebel and government armies surged back and forth over the park for years. Armies on the move are tough on herds, and soon enough there were no more herds, and finally almost nothing left standing. Crocs got through by hiding under water. There is nowhere for a water buffalo to hide from a hungry battalion of soldiers.
That grim time wasn't reductionism, it was just reduction. It was also a long time ago. And it turns out there is a lot to learn from studying the disassembly and revival of the hypervital living economy of Gorongosa. Life is surging here now and the metabolism of the park is putting itself back together again fast. But there is still a huge experiment to be done in Gorongosa as the reboot of the place progresses. That's going to be a big theme in Life on Earth. We're writing it up now and we're going to be following it for years in our future editions as we report on the progress of Greg Carr and his team as they reassemble Gorongosa National Park.
This week ecologist Marc Stalmans gave the textbook project aerial lectures on transition zones in the park--floodplain to copse to forest and so on. It's all about water. But it's also about succession. If grazers don't mow the grasses, browsers don't flourish. If browsers get befuddled, alien things like mimosa move in and grow too tall. The grazing grounds flinch and withdraw. Environmental change is as normal as the day, especially here, and that leaves park managers with countless decisions about how Gorongosa emerges from its recent history.
Human influence can be measured in units of mass and volume of waterborne material pouring into the park from the mountain and from a huge catchment in the northeast. The volumes are rising due to land-use changes outside the park. The sediment is filling in Lake Urema, the heart of Gorongosa's circulatory system. As the lake becomes too shallow, the hippos move elsewhere, taking with them massive activity that stirs up the lake. With their exodus, sediment settles and the lake bed rises.
There are interveners and leave-aloners here, and often after a couple of years working in the park they switch sides. The science is complicated. It was once thought that the lake was fed almost entirely by runoff from higher terrain. It now seems plain, based on isotope comparisons and other techniques, that the lake is sustained by water transfer across a porous stratum between the lake and the aquifer. The surprising discovery was made that more water arrives from the upper catchment than from the mountain. The lake could easily be remodeled by dredging parts of it, which might bring back the hippos, and one learns to trust the power of hippos to model their environment. Water pileups could be created at the outlet. Sediment could be captured on the higher ground by porous barriers. Or the entire scene could be left alone to shape itself according to the laws of nature, with "nature" here meaning a beautiful scene mangled not so long ago by war and now recovering while inhaling the smoke and tailings (goldmines in the buffer, fer criminy's sake) of escalating human impact on the surrounding region.
We're heading out in the truck this afternoon to finish Marc's aerial transition-zone lessons with shoots at the same sites on the ground. We'll cross-cut the shoots with maps and animations to make a lesson that will shock the children awake. One of these days, one of those kids is going to be making decisions about hydrology and hippos at Lake Urema.
Thursday, August 4, 2011
As we circled the area to investigate we could see small huts in the middle of the recent clearings. These were the beginnings of farm houses. We could also see very well-worn paths connecting this area to other parts of the mountain. It was incredibly sad to see the devastation from the air and the network of well-worn paths. Easy to imagine that new surrounding forest would be destroyed in a short amount of time.
We landed in the late afternoon and were instructed by the pilot that we only had a certain amount of time to reach the clearings and make it back to fly out. We discussed our assignments. With Bob’s heavy video camera he wouldn’t be going as high but would cover the lower reaches. Joel and I with our smaller camera kits would try to make it to the top with Marc.
Wednesday, August 3, 2011
During this expedition we have practiced a variety of animal capture and release techniques in order to monitor life in Gorongosa. We have used mist nets for birds, butterfly nets for any flying, ziplock bags for ants, and our cameras for anything else. These are all providing good content for the Life on Earth project to show how biologists conduct animal surveys.
Some collecting trips are planned and others are spontaneous. A good example of the unplanned discovery occurred the other night when Liz came into the dining area and said “There is an enormous spider in my room and it is in my suitcase!” Immediately, Ed stood up and commented “This is an entomologist’s dream! Coming to the aid of a lady in distress.” After a brief search in her room, there it was. A large baboon spider showed up in her clothes. Ed deftly captured the beast near a pair of socks. The Lord of the Ants had saved the lady as I am sure he has many times before.
I just caught myself about to write “The highlight of the trip so far….”, but realized I may have written that too many times already. Is that such a bad thing? If it isn’t already apparent, Gorongosa is filled with “highlights.” For those who love to explore and discover the beauty, complexity, and processes of the natural world, it is a dream.
Yesterday, we had the incredible opportunity to collect specimens within virgin rainforest in upper reaches of Mt. Gorongosa. This was prime habitat for collecting undescribed species. It was a biological explorer’s dream. Coming out of the high plateau grassland into the dense canopy of the rainforest was overwhelming. Everything seemed to be covered by mosses and other bryophytes. The air was still and wet. I arrived on the second helicopter run with Morgan, Liz, Greg and Bailey. As we entered the forest we heard findings had been slim. A reward of “2 Fantas” was announced by Ed. Samples of soil were gently turned and fallen branches moved and replaced. I kneeled down and started removing some bark from a fallen moss-covered limb. After a short while I started finding a variety of insects including two pseudoscorpions. I had previously only found these in the far away habitat of the San Diego Bay intertidal. Peeling away more bark I encountered some spiders I had never seen before. As I reached for a spider, it raced for the edge of the bark and I saw something lunge for it. I peeled back the bark and found a small, dark tree frog. This could a species that has never been seen before.
Within the same region I found a dead ant under the log. Could I truly earn the Fantas? Few things have been more stimulating for me as biologist than collecting ants with Ed. As I approached him with the dead ant I held my arm out and noticed a different species crawling to my hand. Was it being drawn in to the Lord of the Ants? It had possibly fallen from the canopy as Ed said it compared closely to other arboreal ants. The real thrill came when I pried some wood off the surface of the same log and located a small colony of ants. They immediately disappeared under some liverworts and into the wood. Ed had commented on the very cryptic nature of many of the ant species found in a rainforest habitat. These small reddish cryptic ants could be another new species.
Morgan and Ed arranged a great piece on island biogeography within the forest. The setting was ideal. Each of us filming the piece for Life on Earth or assisting in the shoot had to pinch ourselves as we listened to Ed articulate the fundamental concepts of the concept the basic concepts of island biogeography, much of which he is responsible for. The soft green light coming through the canopy and the subtle sounds of sunbirds and surrounding insects in the undergrowth created incredible ambience.
Today in camp Ed spent several hours searching for ants in the leaf litter he returned from Mt. Gorongosa. I assisted him for a while and found it very interesting. This is something I look forward to incorporating in future classes. Overall, he concluded it was relatively barren for a rainforest. However, this may be due to its altitude and cold weather.
A bush baby just called in the night. It sounds like a dying infant who is crying out in the bush. Why would such a small, relatively defenseless primate have such a loud obnoxious call?
Another recent collecting outing I had with Ed was look over some rock rubble on the edge of Camp Chitengo. I told him I had seen some incredibly fast ants while I was filming some ant hills nearby. After several attempts at grabbing these speedy ants I located a plant there were interested in and was able to collect several. Ed speculated these were Cataglyphis ants. They are typically found in desert biomes. Known as the worlds’s fastest ant. This reveals again something of the great biodiversity in this geographically diverse place.
Each morning, there has also been a bird survey team deigned to begin sampling birds with a mist net. This is a black, finely-woven net designed to be invisible for passing birds. There has been success but the birds seem to learn quickly. Such is the nature of life.
Another capture technique I took part in was the darting of a warthog with the veterinarian Carlos for a relocation project. This warthog was not responding to the proper tranquilizers and eventually
Additionally, some specimens are collected by other scientists who have heard of our work in Gorongosa. This reed frog was collected by the Vegetation Team. With the help of some additional experts soon we will be able to identify all of these species.
We will soon demonstrate a variety of means for sampling biodiversity within the Life on Earth Project. One of the fundamental aspects of maintaining a healthy ecosystem is to maintain species richness. If it is measured in soon in Gorongosa then it will be possibly to measure the impact of restoration efforts into the future with regular biodiversity measurements.
Now different bushbaby is crying in the night on the opposite side of camp from the first. Another informal survey. Another species on the primate list for Chitengo Camp. Maybe he/she is telling me it is time for bed.