The Impact of Forest Disturbance on the Seasonal Foraging Ecology of a Critically Endangered African Primate

Abstract

Forest loss and fragmentation threaten many primates globally, and often leads to a reduction in food resources. During a 22-mo period, the foraging ecology of the critically endangered kipunji Rungwecebus kipunji was studied in the heterogeneous Rungwe-Livingstone forests, southwest Tanzania, to identify periods of possible ecological stress, fallback foods used by the species, and the impact of forest disturbance on feeding resources. The studied group had a wide diet and was predominantly frugivorous. Fruit consumption was driven by fruit availability which peaked during the wet season, and dipped during the driest months. During this period, two fallback foods: mature leaves and pith were widely consumed, with Macaranga capensis an essential fallback species. a diversity and evenness of diet was remarkably similar across months, but there was high b diversity in diets at the cusp of wet and dry seasons, and during periods of low fruit availability. This suggests considerable dietary adaptability to fluctuating resources, which may act to buffer against further forest disturbance. Tree species associated with relatively undisturbed forest were significantly more important in the diet, especially in the dry season, than those of disturbed forests. Regeneration of key trees (determined through counting of seedlings and saplings in plots) appeared healthy except in two important Ficus species. Conservation management, while focusing on promoting old growth forest, should also consider populations of some important pioneer tree species such as Macaranga capensis both inside the forest and in any reforestation schemes outside the species' current area of occupancy.Abstract in Kiswahili is available in the online version of this article.

Fruit biomass availability along a forest cover gradient

“…, Bracebridge et al . ). Therefore, the loss of species producing large fruit biomass may lead to important trophic cascading effects, influencing the quality of habitat for fruit‐eating animals and the seed dispersal service provided by them.…”

“…These plant species are mainly present in more forested landscapes, which are known to support a higher density of frugivorous birds (Morante Filho et al 2015). Late successional species are also key resources for primates, and are in general located in undisturbed forests, even though these animals also forage in disturbed sites (Arroyo-Rodr ıguez & Mandujano 2006, Dunn et al 2009, Bracebridge et al 2012). Therefore, the loss of species producing large fruit biomass may lead to important trophic cascading effects, influencing the quality of habitat for fruit-eating animals and the seed dispersal service provided by them.…”

Reliability of macaques as seed dispersers

“…(Nunes, 1998; Russo et al, 2005), hoolock gibbon Hoolock spp. (Fan, Ai, Fei, Zhang, & Yuan, 2013; Hasan, Feeroz, Islam, Kabir, & Begum, 2007), and kipunji Rungwecebus kipunji (Bracebridge et al, 2012). Apart from the presence/absence of plants within a community though, further studies need to be conducted to assess if the abundance of certain plant families or genera or overall vegetation diversity influences the reliability of macaques as seed dispersers overall.…”

“…The percentage constituted by individual fruit genera or families were not available for M. cyclopis and M. sylvanus . The fruit families or genera which constituted > 1% of the yearly diet were considered to be yearly staples (Bracebridge et al, 2012).…”

“…Frugivores may act as effective dispersers for fruit families or genera with restricted geographic distributions in particular habitats. Thus to ensure that our framework does not exclude such fruit families or genera, we included one more criterion: a frugivore genus can also be considered a spatially reliable disperser of certain fruit families or genera if (c) the fruits are preferred by the frugivore (relative consumption greater than relative availability; Russo, Campbell, Dew, Stevenson, & Suarez, 2005) and/or are yearly staples (constitute > 1% of the diet in a year; Bracebridge, Davenport, & Marsden, 2012) in the diets of the frugivore.…”