Individual study: Lemur bridges provide crossing structures over roads within a forested mining concession near Moramanga, Toamasina Province, Madagascar
Mass V., Rakotomanga B., Rakotondratsimba G., Razafindramisa S., Andrianaivomahefa P., Dickinson S., Berner P.O. & Cooke A. (2011) Lemur bridges provide crossing structures over roads within a forested mining concession near Moramanga, Toamasina Province, Madagascar. Conservation Evidence, 8, 11-18
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Install rope or pole (canopy) bridges
A before-and-after trial in 2009-2010 at the Ambatovy mine in humid forest in Toamasina, Madagascar found that all six lemur species (Lemuroidea) monitored used canopy bridges to cross roads and pipelines around the mining area. Observed road crossings on the ground decreased from 69 during two weeks before bridge construction to six crossings during the 1.5 years after construction. Furthermore, bridges were used 63 times during the first 1.5 years. Lemurs preferred to use the mine area bridge, which the authors assumed was due to the shorter distance needed to be crossed without the shelter of the canopy. Three bridges (8–15 m in length) in the mine area and four (22-25 m in length) along the pipelines were constructed from January to February 2009. Lemur (eastern woolly lemur Avahi laniger, greater dwarf lemur Cheirogaleus major, grey bamboo lemur Hapalemur griseus, diademed sifaka Propithecus diadema, brown lemur Eulemur fulvus, red-bellied lemur Eulemur rubriventer) use of bridges was monitored 10 hours/day during four to six days/week from March 2009 until August 2010. Prior to bridge construction, mine area roads and pipelines were monitored for 14 days to detect potential crossing points.
(Summarised by JJ)