Lemurs

Lemuridae (Lemur Family) Area of relevance #1: Ecology of the Genus Eulemur in Madagascar Area of relevance #2: Social Structure of the Varencia population Madagascar is the fourth largest island located just right to South Africa, consisting of 33 unique species, 14 unique genera, and five unique families, all three of these resenting 100 percent levels of endemism. (Nowak, 1999). It’s also a high ranking island for global priorities for conserving primates, typically lemurs. Madagascar is known for its harsh climate, including the three variations of climates on the island. Typically the northern area of Madagascar is a mixture of rainforest and the dry deciduous forest. As the map travels down you notice how throughout the center of Madagascar it’s still that mixture of rainforest and dry deciduous forest but the rainforest is on the eastern side while the dry deciduous forest runs along the west side. And once you reach the south it’s a whole other story. The southern part of Madagascar is dry and typically named “spiny desert forest” and that’s perfect since its one of the harshest climates known on this island. The Eulemur are sexually dichromatic, which means that the males have a dark gray brown back and a dark tail, while the females are usually a light gray. But both the male and female have a V shape on the crown but the male has more orange on his head and black surrounding the V on each side. The Eulemur is cathemeral and arboreal, cathemeral means that they can be out during the day, and also during the night. This is a distinct trait only in this genus. They also have distinct marking habits; males have three different ways to leave their scent. One is anogenital, which means that they can secrete spray from their anus or genitals. This secretion can actually be used to identify the gender and the individual’s identity (Rowe, 1996). They can also mark with their head and hands; this means that they can rub their forehead on objects to claim it. It’s like dogs peeing on areas to mark their territory. The Hapalemur are known as the lesser lemurs since they are calmer than the other genera of Lemuridae. These are special because they specialize in bamboo, so their stomachs have actually adapted to high levels of cyanide, which is lethal to humans. They have no idea how they can consume such high levels of cyanide. They are also crepuscular, which means their primarily active at twilight (Rowe, 1996). Another aspect that affects the lemur’s environment is burning and deforestation by the humans. This killed off eighty percent of Madagascar’s original forest. (Wright, 1999) This is actually called the Holocene Extinction. It ended up destroying seed banks and prevented the restoration of many precious areas. This extinction was said to have killed off the giant lemurs and large predators. These harsh elements have lead to wacky traits in lemurs, such as female dominance in their groups, female-female competition and targeted aggression, there’s also no sexual dimorphism present so that actually leads into monogamy in all species of lemurs. There’s also sperm competition and male-male aggression during mating seasons, which will also lead to infanticide since the males are trying to just spread their genes. Ecology of the Genus Eulemur in Madagascar This is another reason why females express such a strong trait of dominance. They need to keep that priority over the males, since they’re a monogamous species. And the females tend to choose the best male suited for her, and her future infants. These behavioral habits allow for strong traits and adaptations to Madagascar’s deadly environment. Social Structure of the Varecia population Past studies have reported other social organizations in ruffed lemurs including monogamous pair bonding may have been due to the use of short-term, seasonal field studies instead of yearlong studies that take into consideration the effects that changing seasons have on ruffed lemur communities. For instance, during the cold, rainy season, which corresponds with the breeding season, interactions between core groups within a community are significantly reduced. During this time small subgroups form consisting of a mature female, a mature male, and sometimes offspring. This can be misinterpreted as monogamous pair bonding. Activity patterns within the community range vary by gender and season. Males generally stay within a core area all year; whereas females only confine themselves to a core area during the cold, wet season, then expand their range throughout the community range during the hot, rainy season. Females expand their traveling range slightly after giving birth, still staying within the core area, but gradually range further in December when they begin stashing their infants with other community members while they look for food. Females range the furthest later during the hot, rainy season. The Lemuridae in Madagascar has evolved and adapted to Literature Cited Baden, A.L., Brenneman, R.A. 2008. Morphometrics of wild black and white ruffed lemurs. American Journal of Primatology. 70: 913-926 Meyer, C., Gallo, T., Schultz, S.T. 1999. Female dominance in captive red ruffed lemurs Varecia variegate rubra (primates, Lemuridae). Folia Primatologist. 70: 358-361 Nowak, R.M. Primates of the world. 1999. The Johns Hopkins University Press, Baltimore Md. 195 p. Ossi, K., Kamilar, J.M. 2006. Environmental of Eulemur behavior and ecology. Behavioral Ecology and Sociobiology. 53: 14-20 Overdorft, D.J. 1999. Ecological correlates to activity and habitat use of two prosimian primates: Eulemur rubriventer and Eulemur fulvus rufus in Madagascar. American journal of Primatology. 40: 327-342 Pastorini, J., Forstner, M.R.J., Martin, R.D. 2002. Phylogenetic relationships among Lemuridae (primates): evidence from mtDNA. Journal of human evolution. 43: 463-478 Richard, A.F., Dewar, R.E., 1991. Lemur Ecology. Annual Rev. Ecology System. 22: 147-175 Wright, P.C., 1999. Lemur traits and Madagascar ecology: coping with an island environment. Yearbook of physical anthropology. 43: 31-42 Rowe, N., Goodall, J., Mittermeier, R. The Pictorial Guide to the living primates 1996. Pognoias Press, Charlestown Rhode island. 263 p.