Seasonality in Gum and Honeydew Feeding in Gray Mouse Lemurs

Abstract

Exudates represent an important component of the natural diets of ­small-bodied primates. For mouse lemurs, the impact of forest type and seasonal predictability on gum consumption has recently been intensively investigated. The goal of our study was to extend our knowledge regarding the seasonality of feeding ecology of Microcebus murinus, first, to investigate the relative consumption of gum and hemipteran honeydew, a sap-derived product, and, second to assess respective foraging strategies in a highly seasonal and quite predictable environment. We hypothesized that (1) food resources vary according to the season, (2) gum and honeydew represent keystone food resources during periods of food scarcity, and (3) lemurs revisit productive stationary feeding sites during the period of food scarcity. We studied gray mouse lemurs in the dry deciduous ­forest of the Ankarafantsika National Park in northwestern Madagascar. We radio-collared seven M. murinus females and performed focal observations on their feeding behavior during the end of the dry and the beginning of the rainy season. During the dry season, the period of food scarcity, mouse lemurs mainly consumed gum and honeydew. Subjects revisited the same feeding sites within the same and over several nights. During the rainy season, the period of food abundance, lemurs consumed mainly nectar from shrub flowers and did not show gum or honeydew feeding. To our knowledge, the consumption of honeydew by lemurs is a unique case of sap feeding by proxy in a mammal. Further investigations will focus on the characterization of the ecological consequences of such an interaction between mouse lemurs, hemipteran larvae, and host plants.