Sahamalaza weasel lemur

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Sahamalaza weasel lemur
Lepilemur sahamalazensis a.PNG

Sahamalaza weasel lemur ( Lepilemur sahamalazensis )

Systematics
Order : Primates (Primates)
Subordination : Wet-nose primates (Strepsirrhini)
Partial order : Lemurs (Lemuriformes)
Family : Weasel lemurs (Lepilemuridae)
Genre : Weasel lemurs ( Lepilemur )
Type : Sahamalaza weasel lemur
Scientific name
Lepilemur sahamalazensis
Andriaholinirina et al., 2006

The Sahamalaza-Wieselmaki ( Lepilemur sahamalazensis ) is an on Madagascar living primate species from the group of lemurs within the lemurs . The species was first described in 2006 .

features

With a head body length of 19 to 20 centimeters, a tail length of 21 to 26 centimeters and a weight of 0.6 to 0.8 kilograms, Sahamalaza weasel lemurs are among the smaller representatives of the weasel lemurs. The color of the coat is variable and may depend on age. The shoulders and arms are reddish brown, as is the front part of the back, which becomes grayer towards the tail. The hind legs are also gray, but the tail is red-brown or deep brown. As with all weasel lemurs, the head is round, the forehead is red-brown, while the face is gray. The eyes are enlarged to adapt to the nocturnal lifestyle.

distribution

Sahamalaza weasel lemurs are so far only known from the Sahamalaza peninsula in northwestern Madagascar. The Sahamalaza Peninsula is part of a transition zone between the Sambirano region in the north and the western region of dry deciduous forests in the south. These animals live in forests, they can be found in both primary and secondary forests .

population

Olivieri et al. (2005) recorded a density of 4.17 individuals / km² in the Ankarafa forest. This high density could be due to the recent loss of habitat, which forced all animals to focus on the few remaining forest fragments. Ruperti (2007) recorded an average density of 280 individuals / km² in Ankarafa. The latest data on Lepilemur density suggest a density of only 7 to 23 individuals / km² in the same area. The differences between density estimates are most likely due to different methods of data collection. While Ruperti determined the lemur density in one-hectare plots (one for each fragment), Seiler et al. all individuals found during a 12 month field work. Another factor that may have contributed to the differences is the constant change in habitat. During the study period from 2009 to 2011, various observations were made on illegal logging (often hardwood), slash and burn and poaching of the weasel lemurs on the Sahamalaza Peninsula.

Habitat and Ecology

Sahamalaza weasel lemurs are nocturnal and mainly stay in trees. Like all weasel lemurs, these animals stay in tree hollows or in the thickets of trees during the day and look for food alone at night.

Regardless of the differences in the overall structure and the habitat parameters of the forest fragments in Ankarafa, the microhabitat in the home areas of the weasel lemurs and in the vicinity of the sleeping places was similar in all of the measured habitat parameters. The parameters for the different sleeping places were also similar. The animals selected the locations of their territories based on various habitat variables, with the frequency of suitable roosts and food, and tree density and canopy density being the most important factors. Tall trees with large crowns, a high density of small trees and a dense canopy of leaves were particularly important for the choice of sleeping place.

The Sahamalaza weasel lemur is a herbivore that feeds on the leaves of at least 42 different tree species. Leaves of the common species Clitoria lasciva, Mangifera indica, Garcinia pauciflora and Sorindeia madagascariensis are preferred. Occasionally the diet is supplemented with fruits of Ficus tiliaefolia, spiders, insects and insect larvae. There will be longer rest periods during the nightly period of activity. The territories covered an area of ​​1.4 h (nocturnal areas of 0.5 ha) and did not overlap between adult individuals. The very few socio-positive interactions between individuals occurred between mothers and offspring. Although the small number of observed individuals makes it difficult to conclusively draw conclusions about the social organization of the Sahamalza sport lemur, the low social interaction and cohesiveness suggest that Sahamalaza weasel lemurs are solitary.

During the day, the Sahamalaza weasel lemur (with the exception of mother-child pairs) can be found alone in tree holes or in dense branches. Tree holes used as roosts were usually found in Bridelia pervilleana, while roosts in branches are mostly found in Sorindeia madagascariensis. Animals that rested in tree holes usually sat at the entrance rather than inside the hole, possibly to increase sun exposure. During the daily observations, 5-14% activity was recorded, although the animals never left their sleeping places or ate. When comparing the proportion of active behavior between individuals who were resting in tree holes and those who were in branches, animals in tree holes had significantly higher levels of activity.

Resting animals recognized voices of predators as indicators of an increased risk of predators, were able to assign voices to different predators and used species-specific anti-predator behavior. In addition, the examined animals were able to draw conclusions about the presence of predators and predator types from warning calls from other animal species and thus use the possibility of early detection of predators through cross-species communication.

Danger

Sahamalaza weasel lemurs inhabit a small area that has been partially protected. Despite the protection of the area, deforestation for agriculture and logging for charcoal and material continue to increase, especially since the outbreak of the political crisis in Madagascar in 2009. The number of animals hunted is also increasing (Seiler et al. 2012). The IUCN lists the Sahamalaza weasel lemur as critically endangered, the population trend is decreasing.

literature

Web links

Commons : Sahamalaza weasel lemur ( Lepilemur sahamalazensis )  - Collection of images, videos and audio files

Individual evidence

  1. ↑ Olivieri, G., Craul, M., & Radespiel, U .: Inventaires des lémuriens dans 15 fragments de forêt de la province de Mahajanga. Ed .: Lemur News. tape 10 , 2005.
  2. ↑ Ruperti, F .: Population density and habitat preferences of the Sahamalaza sportive lemur (Lepilemur sahamalazensis) at the Ankarafa research site, NW Madagascar. Ed .: Oxford Brookes University. 2007.
  3. ↑ Seiler, M., Holderied, M. and Schwitzer, C .: Vegetation structure and habitat characteristics of differently degraded forest fragments inside the Sahamalaza - Iles Radama National Park, north-western Madagascar. Ed .: Lemur News. tape 17 , 2013, p. 57-63 .
  4. ↑ Seiler, M., Randriatahina, GH, and Schwitzer, C .: Ongoing threats to lemurs and their habitat inside the Sahamalaza - Iles Radama National Park. Ed .: Lemur News. No. 15 , 2010, p. 7-10 .
  5. ↑ Seiler, M., Randriatahina, GH and Schwitzer, C .: The rapid boost of forest destruction and poaching of lemurs inside the Sahamalaza - Iles Radama National Park. Ed .: Lemur News. tape 16 , 2012, p. 28-30 .
  6. ↑ a b c Seiler, M .: The impact of habitat degradation and fragmentation on ecology and behavior of the Sahamalaza Sportive Lemur, Lepilemur sahamalazensis, in northwest Madagascar. Ed .: University of Bristol. 2012.
  7. ↑ a b c d Melanie Seiler, Marc Holderied, Christoph Schwitzer: Effects of Habitat Degradation on Sleeping Site Choice and Use in Sahamalaza Sportive Lemurs (Lepilemur sahamalazensis) . In: International Journal of Primatology . tape 34 , no. 2 , April 1, 2013, ISSN  1573-8604 , p. 260-280 , doi : 10.1007 / s10764-013-9658-z .
  8. ↑ a b c M Seiler, M Holderied, C Schwitzer: Habitat selection and use in the Critically Endangered Sahamalaza sportive lemur Lepilemur sahamalazensis in altered habitat . In: Endangered Species Research . tape 24 , no. 3 , June 13, 2014, ISSN  1863-5407 , p. 273-286 , doi : 10.3354 / esr00596 .
  9. ↑ Melanie Seiler, Christoph Schwitzer, Marc Holderied: Anti-predator behavior of Sahamalaza sportive lemurs, Lepilemur sahamalazensis, at diurnal sleeping sites . In: Contributions to Zoology . tape 82 , no. 3 , ISSN  1383-4517 , p. 131 – S1 ( academia.edu [accessed November 23, 2019]).
  10. ↑ Melanie Seiler, Christoph Schwitzer, Marco Gamba, Marc W. Holderied: Interspecific Semantic Alarm Call Recognition in the Solitary Sahamalaza Sportive Lemur, Lepilemur sahamalazensis . In: PLoS ONE . tape 8 , no. 6 , June 25, 2013, ISSN  1932-6203 , p. e67397 , doi : 10.1371 / journal.pone.0067397 .
  11. ^ The IUCN Red List of Threatened Species. Retrieved November 23, 2019 .