Tales from Tanzania: Oh, the things you’ll find in a caldera

On the next leg of our trip, we visited the Ngorongoro Conservation Area.

NgorongoroNow, you may ask, “Nicole, your last adventure was in a national park, and this is a conservation area — what’s the difference?” And I’d answer that a conservation area has people living on it, whereas in a national park, no permanent settlements are allowed. The Maasi people live in the Ngorongoro Conservation Area with their cattle full time. They have been allowed this exception since they do not hunt. According to their traditional customs, they are only allowed to eat cow, goat and sheep so the wild animals in the crater have nothing to fear from them.

The Ngorongoro Conservation Area is especially interesting, as it contains the largest unbroken caldera in the world. It was created by a volcano, which has now collapsed. Before it collapsed, the volcano would have been much, much higher than Kilimanjaro.

The formation of a caldera

The crater has given rise to a variety of ecosystems due to its geography and sheer size. Moisture is pushed in from the ocean in the east, but it gets caught at the rim of the crater. The outside eastern edge of the crater, therefore, is home to a thick highland forest full of tropical birds. The west side of the crater only gets rain in the rainy season and most of the time looks something like dry west Texas.

Interestingly, the crater is responsible for most of what we have seen and what we will be seeing on this trip. The eastern edge of the crater is so dense that natural springs flow into Lake Manyara rather than the crater, keeping it green and providing a source of water for animals.

Looking to the west, when the volcano erupted 2.5 million years ago, the wind blew the volcanic ash to the Serengeti, which caused hard-packed earth that only the acacia can penetrate.

Later in the evening, we were able to talk to crater naturalist, Yotham, at our hotel. He was very surprised to see several of our pictures (we always knew we were looking at something awesome if one of the driver guides took out a cell phone to take a picture).

In particular, Yotham was surprised to see our shots of the Little Bee Eater, as they usually don’t come into the crater. Instead, they live in the highland forests on the outside western edge.

DSCN1517DSCN1205As we continued to go through our shots, he indicated that we had, in fact, had a very, very good day of observations.

Here are some of the highlights: 

Hyena kill: We arrived right after the wildebeest was taken down. Just out of screen are several other hyenas and 20 or so vultures waiting for their turn at the carcass. The eating hyena kept dragging the carcass away so it could eat without feeling crowded.

DSCN1604Ostrich: So, I learned something new today. When you see a male ostrich with a bright pink neck, it is feeling frisky. A male ostrich with a white or gray neck is not currently interested. Female ostriches are very beautiful but very differently colored than the male ostriches.

DSCN2036DSCN2048Serval: This picture is a bit miraculous. The serval is normally a nocturnal animal, so it was amazing to see it out during the day. AND THEN IT STARTED HUNTING. AND IT WAS AWESOME.

DSCN1957

Great Migrations – New Series Debuts Sunday on NatGeo

Perhaps one of the most compelling segments of National Geographic Channel’s upcoming “Great Migrations” series is the first one, “Born to Move” (premieres Sunday, November 7 on NGC).  In this segment the need to migrate (move) is ingrained in each featured animal as a means to survival.  Featured species include Christmas Island’s red crab (Gecarcoidea natalis), the far-traveling sperm whale (Physeter catodon), and the monarch butterfly’s (Danaus plexippus) annual journey across North America to a single site in central Mexico.  One of the more heartbreaking sagas involves a young wildebeest (Connochaetas taurinus) calf falling prey to Nile crocodiles (Crocodylus niloticus) as its mother watches on helplessly – nature can indeed be cruel, and unfortunately not every story of life terminates in a rainbow.

“Beastly River Battle”
A tragic and violent scene plays out as wildebeest herds attempt to cross a river teeming with crocs.

The footage brings to mind some components of the Frensley/Graham Hall of African Wildlife, which I helped build here at the Houston Museum of Natural Science. In the Okavango Delta diorama, where the theme is “water is life,” we have a plasma screen featuring natural history aspects of the Nile crocodile, some of which I filmed in Kenya’s Samburu River, including footage of the crocs using their group hunting strategy to predate a large impala (Aepyceros melampus) buck.  There is also other footage of crocs predating adult Thompson’s gazelles (Gazella thomsonii) and wildebeest, which is not as painful to watch as the crocs seizing an innocent calf as the mother looks on.

“Moving in Masses” – A zebra foal and his father catch up with the herd
on its way back to the rich green lands of the delta.

In other parts of the African Wildlife Hall we also feature the quintessential Serengeti migrating hoofed mammals, including plains zebra (Equus burchelli) and wildebeest.  Zebras are grazers that may congregate in great numbers in favorable areas.  The zebra’s pattern may serve two functions.  Firstly, when a herd of zebras are observed by a predator the black and white pattern breaks up the outline of individual animals, making it more difficult to pick out a target.  More recently, it has been discovered that the pattern plays a role in triggering and reinforcing herd behavior in the zebra.  For any given Zebra, being in a herd provides more eyes and ears to detect approaching predators; once those predators strike, it is relatively unlikely for any one zebra that it will be the one to be caught.  These advantages outweigh the disadvantage of having such non-camouflaged coloration.  You can witness the zebra’s migration from Botswana’s lush Okavango Delta to the Kalahari Desert in “Race to Survive” (premieres Sunday, November 14).

Great Migrations
Africa: Every spring in Botswana, hundreds of zebras leave the largest inland delta in the world on
a 150-mile slog into hell – a desert of salt and sand – so that their bodies can take in much-needed
minerals. Their stripes help protect them from predators as long as they stick together – blurring
their lines and making them indistinguishable as individual animals.
(Photo Credit: © John Conrad / CORBIS)

The ‘clown of the Serengeti’ or wildebeest, follows the wax and wane of the grasses that sustain them.  Their short-distance migration numbering in the hundreds of thousands is one of the great nature spectacles of our planet.  Harried by predators and the necessity of seeking fresh grazing grounds, the wildebeest manage to mate and give birth while they travel.  Eighty percent of the wildebeest calves (as many as 20,000) are born within several weeks at the start of the rainy seasons and, within minutes, are able to stand and run, traveling with the herd as they migrate.  The vast numbers of newborn far exceed the predator’s kills.  So even though it is heart-wrenching to watch the croc take the life of the wildebeest calf in “Born to Move,” several thousand will survive the journey.  Wildebeest are a keystone species in their habitat, one that if removed, causes the collapse of the community, which revolves around it.

Great Migrations
Africa: White-bearded wildebeest herd: Every year, more than a million wildebeest and
two hundred thousand zebras must chase the seasonal rains, in a 300-mile loop around
Tanzania and Kenya. (Photo Credit: © Anup Shah)

Overall, birds migrate much further than mammals.  For example, wildebeest in East Africa are famous for their annual migration across the Serengeti, which is actually less than 500 miles.  The Arctic Tern in contrast flies 22,000 miles each year on a route that takes it from the Arctic to Antarctic and back again.  When I think of the title of the segment “Born to Move,” I think of many species of birds that are really capable of moving (migrating) very far distances.  This very aspect is highlighted in the African Wildlife Hall’s Saharan Desert diorama where the theme is “perilous migrations”.

As you can imagine, migration has many challenges; the Saharan desert for example is the greatest single obstacle for birds that migrate back and forth between Europe and sub-Saharan Africa.  Covering most of the northern third of the African continent, it takes a songbird 35 to 40 hours to fly across this vast desert.  Many birds fly the desert at night to avoid the intense heat, but there are many other perils birds must face for which they have no solution in their behavioral bag of tricks: traps set by humans, exotic predators such as house cats in unnatural concentrations, tower and window obstructions, environmental extremes such as drought brought on by global climate change, and destroyed habitat every step of the way.  Indeed, migratory birds in the Americas face many of the same perils.

Great Migrations
Nile crocodile with seized Impala buck (horn protruding from water)
in Kenya’s Samburu River, Ethiopian Biome (photo by Daniel M. Brooks/HMNS)

The birds featured in the “perilous migrations” diorama take advantage of the Northern Hemisphere’s annual explosion of food resources, then head south into Africa as fall approaches.  Such migrations offer the advantage of allowing a bird to remain in ‘food-friendly’ seasons.  Whether crossing the Old World or the Americas, a fundamental challenge for migrants is maintaining energy reserves – if a bird runs out of fuel it will perish.  As a result, habitat loss is the greatest threat worldwide for migrants.  Not only must they have suitable habitat in both their nesting and wintering ranges, but along the path in between as well.  During migration many species will stop to ‘refuel’ even in some of the most unlikely environments, such as the Saharan desert.

Featured in the Saharan desert diorama are two birds with contrasting migratory strategies: the lesser grey shrike (Lanius minor) and the grasshopper warbler (Locustella naevia).  Like many other African birds, the shrike nests far to the north in Europe, necessitating a Sahara crossing during migration until it reaches its wintering grounds in southern Africa.  Then it crosses once more for the return trip to Europe.  The warbler migrates a shorter distance through the Saharan desert to stop in central (rather than southern) Africa each winter.

Great Migrations premieres Sunday, Nov. 7 on National Geographic Channel – tune in to this multi-part series learn more about migrations throughout the world; and come by the Museum to view these fascinating animals up close in the Frensley/Graham Hall of African Wildlife.

100 Years – 100 Objects: Evelyn and Herbert Frensley Hall of African Wildlife and Graham Family Presentation of Ecology and Conservation Biomes

The Houston Museum of Natural Science was founded in 1909 – meaning that the curators of the Houston Museum of Natural Science have been collecting and preserving natural and cultural treasures for a hundred years now. For this yearlong series, our current curators have chosen one hundred exceptional objects from the Museum’s immense storehouse of specimens and artifacts—one for each year of our history. Check back here frequently to learn more about this diverse selection of behind-the-scenes curiosities—we will post the image and description of a new object every few days.

This description is from Dan, the museum’s curator of vertebrate zoology. He’s chosen a selection of objects that represent the most fascinating animals in the Museum’s collections, that we’ll be sharing here – and at 100.hmns.org- throughout the year.

collection-of-african-mammal-and-bird-mounts-resizeThe Evelyn and Herbert Frensley Hall of African Wildlife and Graham Family Presentation of Ecology and Conservation Biomes is an important exhibit at the Houston Museum of Natural Science, as it transports visitors to an area of the world that many will never be able to experience first-hand. 

The continent of Africa has been studied and portrayed by the staffs of various museums from the inception of the same institutions.  One of the more famous African wildlife halls is at American Museum of Natural History in New York – the Akeley Hall of African Mammals is comprised of a traditional “menagerie” of African animals, many of which were collected by the late Theodore Roosevelt.

collection-of-african-mammal-and-bird-mounts-crop-2The exhibit at HMNS focuses on African wildlife ecology and conservation using various themes in animal ecology to portray the African vertebrates represented in HMNS’ collection.

Range across seven biomes to explore the entire continent of Africa in the Evelyn and Herbert Frensley Hall of African Wildlife, a permanent exhibition at the Houston Museum of Natural Science.

You can see more images of this fascinating exhibition – as well as the other objects we’ve posted so far this year – in the 100 Objects section at 100.hmns.org