Mouse Lemurs: Origins, Morphology, Behaviour and Other Interesting Features
The nocturnal mouse lemurs (genus Microcebus) are the tiniest primates in existence. Two species of mouse lemurs were known in 1990, one in the dry woodlands of western and southern Madagascar as well as one in the eastern rainforests. However, at present several more species have been discovered. In this article, we will look into the morphology, habitat behaviour and other peculiar features of the mouse lemurs in detail.
Evolution of the lemur species
Since their arrival in Madagascar, lemurs have evolved considerably. According to molecular analyses, there have been two significant periods of diversification from which all known current, as well as extinct family lineages, have originated.
The first diversification
During the first phase, which took place between the Late Eocene (42 million years ago) and the Oligocene (42 million years ago) (30 mya), global cooling occurred and changes in ocean currents affected weather patterns. These erratic changes led to the divergence of lorisoid primates as well as the five major clades of squirrels, all of which occupy niches comparable to lemurs. However, there is some debate as to which species diverged first. Some scientists argue that Cheirogaleidae and Lepilemuridae diverged the earliest, while others believe that the Indriidae and Lemuridae were the first to diverge.
The second diversification
The second major period of diversification occurred during the Late Miocene, between 8 and 12 million years ago, and includes the real lemurs (Eulemur) as well as mouse lemurs (Microcebus). This occurrence corresponded with the start of the Indian monsoons, the last big shift in Madagascar’s climate. In fact, when humans arrived on the island some 2,000 years ago, the populations of both true and mouse lemurs were considered to have separated owing to habitat fragmentation.
The mouse lemurs look similar to one another. True lemurs, on the other hand, are more easily distinguished and display sexual dichromatism. Understanding their phylogeny and diversity has also benefited from research in karyology, molecular genetics, as well as biogeographic patterns. True lemurs are frequently diurnal, allowing possible mates to readily identify one another as well as other related species. In contrast, mouse lemurs are nocturnal, limiting their capacity to exploit visual signals for mating selection. Instead, they rely on smell as well as aural cues. Lastly, true lemurs may have acquired sexual dichromatism as a result of these factors, whereas mouse lemurs may have evolved to be cryptic species.
Originally posted on mouse lemurs!