Gelada Fields and Wild Coffee Trees

The highlands of Ethiopia host a unique fauna quite different from the typical species one expects when they think of Africa. During the Miocene, an era that ended 5 million years ago, much of the region was uninhabitable because of rampant vulcanism, then the climate fluctuations of the Pliocene and the Pleistocene made the environment a difficult region for many of Africa’s more famous species. During Ice Ages glaciers expanded on top of the highest elevations. The region is also isolated from the rest of Africa by rivers and rift valley cliffs. However, the isolation has protected some species that were formerly more widespread in Africa during the Pleistocene. Fossil evidence suggests gelada baboons (Therapithicus gelada) and mountain nyalas (Tragalophus buxtoni) occurred over much of Africa during the Pleistocene, but today they are restricted to the Ethiopian highlands. Both live in regions once difficult for humans to access. Geladas feed in troops of over 100, and when they forage through an area, they devastate the plant life. Certain species of plants then invade these gelada fields. Geladas sleep on cliffs, safe from predators, and they huddle together. This, along with their thick coats, helps them endure the cold nights of the African alpine grasslands. Nubian ibex also hop along the cliffs that predators have a hard time reaching.

Gelada baboons sit on their haunches and eat grass all day, creating gelada fields. They devastate the plant life when they forage. Different species of plants then colonize the disturbed area.

Mountain nyalas feed upon the aromatic herbs that grow on Afro-alpine grasslands.

Nubian ibex are safe from most natural predators on inaccessible cliffs.

Ethiopian wolves specialize in hunting large rats that inhabit the highlands.

Thick-billed ravens use their bills to sift through rat middens to find animal and plant matter. Wattled cranes also sift through rat middens.

There are 8 endemic species of rodents on the Ethiopian highlands including grass rats (Arvicanthus blicki) and root rats (Tachyoryctes macrocephala). Eagles and Ethiopian wolves (Canis sinensis) prey on these rats. The wolves specialize in ambushing them–their teeth are better adapted to hunting these large biting rodents than jackal’s teeth are. Ethiopian highland birdlife too is unique. The blue-winged sheldgoose (Cyanochen cyanoptera) is a grazing goose with a population that formerly was thought to have been founded by a vagrant from the South American grasslands where it was thought to have originated. The similarity with South American geese seems to be an example of convergent evolution because genetic evidence suggests it is most closely related to another species of African shelduck. Humans felling trees in Ethiopia’s forests opened up more favorable habitat for white collared pigeons and thick billed ravens, 2 of the more common birds in the country.

The Kaffa Biosphere Reserve in Ethiopia hosts more typical African wildlife including 178 species of birds, and an astonishing 300 species of mammals. Although over 600,000 people live here, there are still elephants, hippos, lions (though rare), water buffalo, reed buck, duikers, 4 species of mongoose, genets, servals, civets, honey badgers, olive baboons, and many other species of monkeys. Habitats include cloud forests, montane forests, riverine forests, bamboo jungles, and wetlands. Kaffa literally means coffee, and wild coffee trees still grow here.

Location and map of the Kaffa Biosphere Reserve in Ethiopia.

Wild coffee (Coffee arabica) grows in the understory of forests that used to be dominated by yellow wood, sandalwood, stink wood, and crotus. Today, these overstory trees have mostly been replaced by invasive Australian species. People still gather wild coffee fruits. The fruits are edible, but the coffee we drink is made from the seeds after they have been roasted and ground. Ethiopia is where coffee originated, and the country’s farms produce quality coffee. However, 85% of the coffee consumed in the world is grown in Latin America. The leading coffee producers are Columbia, Jamaica, Guatemala, and Costa Rica. Coffee is also grown in Hawaii where it has escaped cultivation to become an invasive species. C. arabica prefers to grow in the foothills of cloud forests, but another species C. camphora grows in tropical forests. Neither species can survive frost.

Reference:

Kingdom, J.

Island Africa

Princeton University Press 1989

Phinizy Swamp February 2025

Phinizy Swamp is an extensive protected wetland located about a 15-minute drive from my house in Augusta, Georgia. It’s used to filter the city’s sewer effluent. I visited the park last Friday and identified 8 species of birds and 2 species of reptiles in about an hour. I encountered a cardinal, a mallard duck, a flock of coots, cormorants, thrushes, purple gallinules, a great blue heron, a Eurasian ring-collared dove, a green anole, and 2 alligators. I saw at least 2 other species of birds, but they wouldn’t stay still for my camera, and I couldn’t identify them. I didn’t see any migratory ducks–maybe they already returned north. The soil in this wetland is very fertile from the sewage run-off, and heavy nitrogen-feeding plants such as bamboo cane and cattail are common. Cypress festooned with Spanish moss is 1 of the more abundant tree species here.

Bamboo cane and cattails thrive in nitrogen-enriched soils, and they are the most common aquatic plants in the park.

Spanish moss, a relative of pineapple, hangs from bald cypress trees.

Another view of bald cypress. This redwood relative is deciduous–unusual for a coniferous tree.

This mallard duck was still sleeping when we returned 30 minutes later.

I think this is either a hermit thrush or a wood thrush. They look similar, are closely related, and belong to the same genus-Hylocichla. I saw quite a few. It’s probably a wood thrush. Wood thrushes are year round residents and are also known as swamp thrushes. Hermit thrushes are migratory and spend summers in Canada and a few regions south of the Canadian border. They are known to return north early.

Crested cormorants drying their wings. They swim underwater and eat fish.

Purple gallinule.

We saw a pair of alligators. It was hard to see in my camera because of the sun’s glare. I estimate these are a 4-footer and a 6-footer. The 6-footer was much bulkier and older.

A photo of the larger alligator sunning itself. It was an unusually warm day for February even in Augusta. Thermometer in the shade hit 78 degrees F.