The threats of fragmentation and the variables influencing primate population viability. Threats causing and as a consequence of fragmentation, some underlying drivers to the threats, and how these threats impact primate population viability and ecological services; the interrelationships between the variables and their conditions, and how they influence primate population viability in fragments; and how knowing specific threats, their causes and consequences, and their underlying causes can guide better the development of appropriate conservation responses and mitigation measures.

Ring-tailed lemur in the Anja Reserve forest fragment with adjacent rice field in the distance.

Adult male Bale monkey feeding on maize collected from cultivated land nearby.

Two adult males of the Bulindi chimpanzee community sharing a large cultivated jackfruit (Artocarpus heterophyllus) (Photo by Jacqueline Rohen).

An adult male of collared brown lemur, Eulemur collaris, resting in the Mandena littoral forest (credit: Jennifer Chambler).

Distribution across Madagascar of articles testing the impact of fragmentation on lemurs.

Heatmap showing the directional influence of various habitat metrics (F1: habitat area; F2: fragmentation; and F3: landscape complexity) and protected area metrics on the occurrence of diurnal and cathemeral lemur species belonging to the families Lemuridae and Indriidae. Empty boxes indicate variables that have been excluded after model selection. Species with no box are species for which the only-intercept model scored best.

Graphical flowchart of how pseudo-absence points were determined. (a) Fragment and with survey transect. (b) Addition of detection buffer. (c) Location of presence points. (d) Home range buffer placed on detection point. (e) Pseudo-absence point placed within detection buffer absence zones. (f) Presence and pseudo-absence landscape scale buffers.

Small nocturnal lemurs and rats are distributed differently in dry forest landscapes in northwestern Madagascar. Endangered Microcebus ravelobensis and endemic Eliurus myoxinus are more sensitive to fragmentation than the widespread M. murinus and the invasive Rattus rattus. There was no evidence for competition between species

Realized habitat distribution of crowned lemurs (Eulemur coronatus) in Oronjia Forest New Protected Area, northern Madagascar.