Most people’s encounters with lemurs have occurred through their representations in popular children’s media, like Zoboomafoo or Madagascar. However, most people don’t know that lemurs play an important role in forest renewal and that they’re currently in grave danger from climate change.
In my home country of Madagascar, there is an amazing array of creatures that are not found anywhere else in the world. Madagascar is a biodiversity hotspot, and approximately 90 per cent of plant and animal species on this island are endemic.
Among them are lemurs, a group of primates that are not only the flagship symbols of the island’s fauna, but also one of the key players in the health and stability of Madagascar’s ecosystems because they do the very important work of dispersing seeds.
I am a primatologist who researches the interactions between infant-and-mother lemur dyads in wild. Their bond is a reminder of what we stand to lose, as it shows care, learning and viability. When forests disappear, so does this fragile bond, and a whole way of life we can never replace.
Lemurs’ habitats and survival are increasingly being threatened by human activities such as deforestation, forest resource exploitation and hunting. There is an urgent need for conservation projects that involve local communities in preserving Madagascar’s unique biodiversity.
Charismatic animals
Due to their charisma, media attention and their biological significance, lemurs attract tourists and researchers to Madagascar. The viability of lemurs is essential to the island’s future, both economically but especially in terms of protecting biodiversity. As they eat fruits from trees like ebony, mammea and wild coffee and then scatter seeds through their droppings, they help new plants grow.
Among the 105 lemur species of Madagascar, Propithecus candidus, commonly known as the silky sifaka, is one of the most endangered species. Only around 250 of them are currently living in the wild.
As their name implies, silky sifakas have visually striking long white hair, and they can only be found in the misty, mountainous rainforests of northeastern Madagascar.
Silky sifakas are primarily active during the daytime, and can travel very quickly through the trees by vertically clinging to them and leaping from tree to tree using their powerful legs. They have highly specialized diets consisting of leaves, flowers and fruits like Diospyros pervilleana, a native ebony species from Madagascar.
Observing mothers and infants
I have spent 10 years studying and following lemurs daily. During my fieldwork in northeastern Madagascar, I closely observed how deforestation and habitat fragmentation affect silky sifaka females and their young.
I studied these females during their lactation season in three different forest contexts: Marojejy National Park (a mostly untouched primary rainforest), Makira Natural Park (a mix of old-growth and re-generating forest) and Anjanaharibe-Sud Special Reserve (known as COMATSA-Sud, a primary forest with heavily degraded areas).
At each forest, the forest canopy, which provides both shelter and food for the lemurs, measured above 10 metres at all sites, but was semi-open, which is a sign of habitat degradation. A semi-open canopy allows more light to permeate the forest canopy, but it also exposes animals to predators and decreases the quantity of high-quality food.
Mothers’ movements and behaviours
One clear difference between the three sites is how mother–infant pairs move and use space. In Marojejy, where the forest is more continuous even if the canopy is partly open, mothers and babies stay within fairly fixed areas, following the same paths and resting spots.
But in places like Makira and COMATSA-Sud, where the forest is broken up into separate patches, mothers have to travel farther and more unpredictably, moving between these isolated patches. This extra travelling causes them to burn more energy and face higher risks from predators and hunters.
These differences show that fragmentation doesn’t just affect food availability, but also changes how these lemurs move and survive.
Forest fragmentation affects lemurs’ social behaviour and grouping patterns to deal with low food availability. It also impacts their health and development; a poor diet causes malnourishment in the lemurs.
Poor nutritional quality
While the food availability for silky sifakas in northeastern Madagascar during the lactation season is relatively abundant, it is of low nutritional quality.
This leads to increased stress and competition as dominant lactating females, desperate to feed their infants, attack subordinates to accumulate more nutrients to produce higher quality milk.
As offspring start to feed on non-milk foods, the poor nutritional quality of available plants after weaning can lead to poor health and stunted growth.
Engaging the community
The decline of lemur populations, particularly silky sifakas, shows the need for urgent conservation action. Continued monitoring — as well as sustained support and funding for Malagasy scientists — is crucial for long-term lemur and biodiversity conservation.
When it comes to the effects of human activity, this decline — habitat fragmentation, global climate change and deforestation — is the result of large-scale activites such as extraction, tourism and state infrastructural development.
Education and awareness campaigns are crucial, both in Madagascar and internationally, to inform people about lemurs’ habitat needs and what can be done to prevent their extinction.
Conservation will never be successful without building an appreciation of the environmental, cultural and economic value of lemurs and the forests they inhabit.
The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
This article was originally published on The Conversation. Read the original article.
