Madagascar highlights

We’ve just returned from a two week adventure in Madagascar, during which we visited a variety of humid tropical forest and dry forest habitats in a few of the 19 national parks to see some of the country’s endemic species of lemurs, reptiles, plants, and insects.

There are over 100 lemur species in Madagascar, all of which evolved on the island from a single ancestor that found its way there after the island separated from Africa and India. The Golden Bamboo Lemur is one of the rarest and most endangered.. First discovered in 1986, its presence, along with other critically endangered fauna in the same area, led to the formation of Ranomafana National Park in 1991.

Ring-tailed Mongoose or Vontsira, medium sized weasel-like mammals, are one of the ten species of carnivores in Madagascar. Some scientists believe that all Madagascar carnivore species evolved from a single ancestor that may have rafted to Madagascar from Africa.

Photo from Wikipedia

There are 283 bird species in Madagascar, 40% of which are endemic to the island. This means Madagascar has the highest percentage of endemic bird species in the world at this time. However, many species are on the EDGE, literally and by category (evolutionarily distinct and globally endangered).

The spectacular Paradise Flycatchers are widespread in Madagascar but are also found in the Comoros Islands, I.e., it is not endemic to just Madagascar. They are relatively common in all forest types except montane, and are one of the few bird species of least concern on the island.

Crested Coua and eight other Coua species are all endemic to the island. They are jay-like in their behavior, even sounding like a Jay, but are related to cuckoos. They are rather weak flyers and hop between ground and low branches rather than flying in the dry deciduous forest.

Malagasy Kingfishers are one of two endemic kingfisher species. Only 5 inches long, their brilliant coloration nevertheless makes them stand out in their wetland habitat.

All 72 species of chameleons are endemic to Madagascar. The Blue-legged Chameleon, also known as the cryptic chameleon, can change its brilliant colors into dull brown to avoid detection.

The Madagascar Collared Iguana is not related to iguanas of the Americas, but is in a separate family. They do act like iguanas though and can be found on the trunks of trees as well as the ground in the dry forest.

Madagascar Brilliant Blue is a nymphalid butterfly found on many of the islands of the western Indian Ocean. There are more butterfly species (300+) than bird species on Madagascar, about 210 of which are native just to Madagascar alone.

Insects like the Giraffe-necked weevil may have been blown from Africa to Madagascar. This odd little beetle has a long tubular neck used for fighting in males.

Baobab alley on the western coastal area of the island features the giant baobab trees that are remnants of the dry deciduous forest that used to be here. The tough, thick bark at the base of the trees resisted the “slash and burn” efforts of the farmers to clear the land here, leaving them standing among the rice paddies.

There are over 900 Orchid species in Madagascar, an astounding 83% of which are native to the island.

The astounding biodiversity in Madagascar is a product of its long evolutionary isolation and its diverse topography. Central highlands (up to 8000 feet) drop off to the east where a wet climate produces lush tropical rainforest along the length of the island at mid and low altitudes. To the east, the rain shadow effect of the highlands results in a series of rolling hills of grasslands, eventually giving way to dry deciduous forest along the west coast and spiny forest at the southern tip. So many environments, so many niches to fill, so much biodiversity.

But this amazing biodiversity is fragile and vulnerable to the presence and actions of humans that have colonized the island for the past 2000 years and have transformed the landscape for agriculture.

Hillside forests are gone, replaced by terraces of rice paddies and vegetable gardens. (Click on the photo to enlarge the view.)

Men spade up the ground after harvesting to start another crop. The land is continually in production, aided by irrigation from local rivers.

Loss of habitat, especially removal of trees that provide food and protection for animals, is a major threat to Madagascar’s biodiversity. Add to that the pressure from a rapidly growing and expanding human population (30 million in 2023) and increasing extremes in weather that have changed the periodicity and extent of wet and dry seasons. The challenges to protect biodiversity are enormous, and risk of failure is high. Species facing the greatest threats (according to an article from the journal Science in 2022) are fish, mammals (especially lemurs), amphibians and mollusks, as well as a wide variety of plants.

EP= extinct before 1500 CE. EX= extinct after 1500 CE. EW = extinct in the wild. CR/PE= critically endangered, possibly extinct. CR= critically endangered. EN= endangered. VU= vulnerable. NT= not threatened. LC = least concern. From Ralimanana et al., Science, 2 Dec 2022.