Madagascar is often called the eighth continent, underscoring its unique ecology and geography. Located approximately 250 miles off the east coast of Africa, the island is the fourth largest in the world. It boasts a landmass only somewhat less than the combined area of California and Oregon. The landscape is diverse, with high mountains rising along its eastern shore and a gently sloping plateau that reaches sea level on the Mozambique Channel. Tropical rainforests cover the eastern mountains, dry forests in the west, and desert-like scrub in the southwest. People only colonized this island some 1500 to 2000 years ago.
Madagascar and India separated from Africa about 120 million years ago (mya), and then India took off north about 88 mya, eventually crashing into Asia and forming the Himalayas. Madagascar has been isolated since before the massive extinction at the end of the Cretaceous, some 66 mya, that killed off the dinosaurs and over 75% of terrestrial life. The island now supports a diverse and unique assemblage of mammals, birds, reptiles, frogs, insects, and plants. The origin and evolution of this biota have fascinated me since I started graduate school in 1975.
A Whippersnapper
Imagine a young whippersnapper, not quite 24 years old, and his excitement at being accepted to graduate school, an opportunity to study birds, his long-time dream. Early that first fall, his major professor invited him to visit Archbold Biological Station, where the professor had a long-term study of Florida Scrub Jays underway. This place might be a good site for his master’s thesis research. The station is in central Florida along the Lake Wales Ridge and a little south of Lake Placid. The ecosystem there was all new for this Pennsylvania farm boy.
After dropping things in a station’s cabin, the young dude walked with his major professor into the dining area. A long rectangular table that could sit 16 stretched from the opening. Opposite the head of the table was a large glass case with the most beautiful, detailed replica of a multi-mast sailing ship. Everything was made of wood, cloth, and fine rope. The vessel, probably 4-feet long, was just magnificent and clearly handmade.
On top of that case were two additional glass boxes, stacked one on the other. The upper one contained an ostrich egg. Ostrich eggs are nearly 6 inches long, over 5 inches wide, and weigh 3 pounds. It had been blown, so it was just the shell, intact except for a small hole on one end. Between the Ostrich egg and the ship was a much bigger egg, the equivalent of two one-gallon milk jugs glued together. This young whippersnapper joked, “Oh, is that an elephant egg,” thinking he was funny.
“Yes, an elephant bird egg from Madagascar,” said his major professor with a stern face and no indication of a smile. That young whippersnapper melted in embarrassment, for he had never heard of an elephant bird. Aepyornis species, elephant birds, reached 10 feet tall, and the largest species weighed about 1,000 pounds, which was four times heavier than an ostrich. An ostrich egg is the equivalent of two dozen chicken eggs. An Aepyornis egg is the equivalent of 12 to 13 dozen chicken eggs. Madagascar had several species of Aepyornis and another small, ostrich-sized genus with several species. They may have survived until about 500 years ago. Richard Archbold brought the egg back from Madagascar in the 1930s. It is known as a subfossil, and its age was never determined.
Richard Archbold founded the Biological Station. In the 1930s, he was a major donor to the American Museum of Natural History in New York. He financed a scientific expedition to Madagascar in the early 1930s and flew the research team there in his four-engine float plane. Later in that decade, he funded a similar expedition to New Guinea. The station had many artifacts from both expeditions. When World War II broke out, Richard Archbold purchased land on Lake Wales Ridge and established the biological station.
That young whippersnapper was me, and I am still amazed that my major professor didn’t send me packing. That day, my life-long fascination with Madagascar began, and I set my sights on seeing the country and its unique assemblage of wildlife and plants. The island supports five extant families of birds found nowhere else, several mammal families, and lots of frogs, reptiles, and plants, all of which are endemic to this fourth-largest island. It also hosted several species of elephant birds, one being the largest bird ever to roam the earth.
In 2024, at 73 years old, I and four friends embarked on a six-week trip to explore as much as possible. I named this expedition “In Search of the Elephant Bird.” In a dozen places, I imagined what it would have been like to see these magnificent birds, as well as extinct giant lemurs, giant tortoises, and pygmy hippos, walking through the habitat.
Mammal Evolution
Birds can fly, and the ancestors of each living endemic avian family presumably reach Madagascar by their wings. Even the ancestor of elephant birds is thought to have been a small bird, like a modern-day rail, that came by flight. When I was in graduate school, it was assumed they had gotten to the island before it separated from Africa because these are large flightless birds. Modern genetic analyses, though, convincingly suggest that all the ratites, ostriches, emus, cassowaries, rheas, and moas arrived on their respective continents or islands as small flying birds. Their ancestor had the “genetic capacity” to evolve into giant birds, presumably to escape predation. Mammals, except bats, can’t fly.
The fireball that circled the earth after the meteor hit near Yucatan 66 mya killed all the dinosaurs and early mammals found on Madagascar. It remains controversial how living mammal ancestors made it to the island. Some have proposed that temporary land bridges must have formed; others suggest that small islands in the Mozambique Channel popped up when the sea level was lower and allowed island hopping. However, little to no geologic data support these hypotheses. Most scientists now think they arrived by rafting on mats of logs and vegetation that crossed the channel from Africa. The problem is that the modern-day currents in the Mozambique Channel are not conducive to a raft successfully making it from Africa.
Madagascar and Africa have gradually been drifting north since the meteor hit. Twenty to sixty mya, they were farther south, and trade winds created a different dynamic of currents that might have allowed rafts to make it across the channel occasionally. The ancestor of four non-volant mammal groups have made it: tenrecs, carnivorans, Nesomyine rodents, and lemurs. Three species of pygmy hippos also lived on Madagascar and went extinct after humans arrived. They are more recent arrivals than the other mammal groups, presumably by floating from Africa.
Lemurs
Lemurs are primates and are distant relatives of monkeys, apes, and humans. Genetic analyses suggest that their ancestor originated in Africa around 50-60 million years ago and subsequently migrated across the Mozambique Channel. At least one pregnant female, or possibly a male and female pair, made landfall, coming by a raft of vegetation. Mouse Lemurs are small and can go into torpor to conserve energy. Some think the ancestor might have been small and could enter a torpor to conserve energy. Many lemurs can also store fat in their tails for leaner times. The immigrant had to survive without food for quite a period, maybe a month, to make that journey.
There are more than a hundred living lemur species now in Madagascar, all of which have evolved from this founding individual or pair. The indri is the largest living member, weighing up to 20 pounds. Some of the extinct ones were much bigger, with one of the sloth-like lemurs growing to the size of a male gorilla. Lemurs may be the most recognized member of Madagascar’s fauna. The animated movie Madagascar featured a ring-tailed lemur as a leading figure.
Lemurs are classified in the suborder Strepsirrhini, commonly called “wet-nosed primates.” Humans, apes, and monkeys have dry noses and are in a separate suborder. Three infraorders occur in the wet-nosed primates, the aye-ayes, all true lemurs, and a third containing their close relatives in Africa and Asia. Monkeys and apes evolved after the lemur ancestor made it to Madagascar, and they outcompeted most lemur relatives on the continents. Now, just a few species in that third group, known as galagos, pottos, and lorises, survive in tropical forests of Africa and Asia. They are small and nocturnal, remaining hidden most of the time.
The lemur ancestor had Madagascar to itself, for monkeys and apes never made it there until about 2,000 years ago when humans colonized the island. All current and extinct lemurs evolved from that original immigrant. The island is diverse in habitats and geography. Over the last 60 million years, the world has gone through at least two major ice ages, one in the Oligocene-Miocene and another in the Pleistocene. Between the ice ages, climates also varied in temperature and wetness. These climatic variations would have shifted vegetation types, making new barriers to dispersal and creating isolated populations that could evolve under unique selective pressures. Evolutionary biologists know this as adaptive radiation, and the diversity of living and extinct lemurs is remarkable.
Some are adapted to feed at night, others during the day, and a few feed day and night. The aye-aye is unique, bizarre in many ways, and classified in a separate infraorder and family. The rest occur in four other families: mouse and dwarf lemurs, sportive lemurs, true lemurs, and finally, the avahis, sifakas, and the indri. Recent genetic work has divided groups like the mouse and dwarf lemurs into many separate species that are geographically isolated. Many look the same to us and are identified at the species level by genetics, but location helps naturalists recognize the difference.
Lemurs exemplify an extraordinary instance of adaptive radiation, where they have successfully filled multiple ecological niches and adopted diverse lifestyles. The Galapagos finches serve as another notable example of this phenomenon. My quest included looking for members of all five lemur families and having a chance to watch their behaviors, see where they lived, and learn as much as possible about them.
Our Tour
We worked with Birds and Birding Madagascar to develop an itinerary that allowed us to see many habitats in Madagascar. The parent company is Cactus Tours Madagascar. Our guides were outstanding. We had a national-level guide who took us to many wild areas and then one to three local guides who knew where species might be found and had deep knowledge of these areas’ ecology and conservation. We also were able to experience and learn about Madagascar’s culture. We spent six weeks in the country, meeting many wonderful people, learning so much, and enjoying the hospitality and joy of the people. I hope I have a chance to return.
A link to my Portfolio from our Madagascar Trip. More will be added as time goes along.
https://www.thomasbancroft.com/index/G0000E6smmgcwmKI/I0000dn601bH0rVs
#Madagascar #Lemur #NationalPark #Madagascarwildlife #Madagascarphotography #Madagascarlemurs #lemurs #Elephantbird #Aepyornis #AyeAye #primates #Naturephotography
Nice report. We toured Madagascar in 2001 when some of the species of birds were still thought to be extinct. We missed Red Owl, Sakalava rail, Madagascar Pochard, Bernier’s Vanga, Aye-aye and Foosa and some the new lemurs up north, so still a desire to go back.
Thanks, Garry. It is a great country and I’d love to go back again. We missed some stuff that I’d hoped to see but saw a lot. We did get the Pochard and our local guide had been part of the effort to save it. All our guides were really knowledgeable and that was fun.