Primary seed dispersal by a sigmodontine rodent assemblage in a Peruvian montane forest

Abstract

Abstract:We examined quantity and quality components of primary seed dispersal for an assemblage of sigmodontine rodents in a high-elevation montane tropical forest in Peru. We collected faecal samples from 134 individuals belonging to seven rodent species from the subfamily Sigmodontinae (Cricetidae) over a 2-y period. We conducted seed viability tests for seeds found in faecal samples. We identified seeds from eight plant families (Bromeliaceae, Annonaceae, Brassicaceae, Ericaceae, Melastomatacae, Myrtaceae, Rosaceae, Solanaceae), nine genera and 13 morphospecies. The most abundant seeds belonged to Gaultheria sp. 1 (46% of total) and Miconia sp. 1 (31% of total), while the most viable seeds belonged to Greigia sp. (84% viability) and Guatteria sp. (80% viability). We utilized relative rodent abundance, seed species diversity, seed abundance and seed viability per rodent species to calculate an index of rodent disperser effectiveness, and found that Thomasomys kalinowskii was the most effective disperser, followed by Akodon torques, Calomys sorellus, Thomasomys oreas, Oligoryzomys andinus and Microryzomys minutus. Plant genera dispersed by sigmodontine rodents overlapped more with bird-and terrestrial-mammal-dispersed plants than with bat-dispersed plants. Future neotropical seed dispersal studies should consider small rodents as potential seed-dispersers, especially in tropical habitats where small-seeded, berry-forming shrubs and trees are present.

Food habits and endozoochorous seed dispersal by small rodents (Cricetidae and Echimyidae) in a riparian forest in southeastern Brazil

“…Species belonging to the Melastomataceae and Rubiaceae in the Neotropics produce fruits that have been recorded as being consumed and dispersed by small pas-serines (Tabarelli and Peres 2002;Silveira et al 2012), didelphid marsupials (Lessa et al 2010;Cáceres and Lessa 2012;Lessa et al 2013) and also small rodents (Horn et al 2008;Vieira et al 2003;Lessa and Costa 2009;Sahley et al 2016). The Melastomatomes Clidemia spp.…”

“…2008 Brewer andRejmanék 1999;Almeida and Galetti 2007;Haugaasen et al 2010). These animals can, however, also act as endozoochorous dispersers, consuming and dispersing viable seeds after gut passage (Horn et al 2008 Lessa andCosta 2009;Dittel et al 2015;Sahley et al 2016). In this context, rodents are particularly important and can act as dispersing agents, transporting seeds from one location to another (Horn et al 2008 Carvajal andAdler 2008;Lessa and Costa 2009;Dittel et al 2015;Sahley et al 2016), or also as mortality agents, damaging the seeds consumed (Briani and Junior 2007;Carvajal and Adler 2008;David et al 2015).…”

“…Therefore, the role of small mammals as potential seed dispersers is usually related to the consumption of a wide variety of fruits and the presence of intact seeds in their feces, with generally increased germinability (Magnusson and Sanaiotti 1987;Vieira et al 2006;Lessa and Costa 2009;Lessa et al 2013). However, the process of gut scarification of the seed coat by passage through the digestive tract of small mammals (rodents and marsupials) does not always have positive effects on the germinability of the ingested seeds (see Traveset 1998;Lessa and Costa 2009;Cantor et al 2010;Lessa et al 2013;Sahley et al 2016).…”

Duality of interaction outcomes in a plant–frugivore multilayer network

“…Assessing the viability of seeds collected from small mammal feces is extremely difficult (see different approaches in Traveset and Verdú , Traveset et al , Sahley et al , Campos et al ). The tetrazolium test used here, which has largely been used in agriculture rather than in community ecology, is an efficient tool to access an important component of seed dispersal quality (Schupp et al ).…”

A comparison of small mammal communities in two High-Andean Polylepis woodlands in Ecuador

“…In order to assess the capacity of a mid-successional woodland to maintain biotic diversity and the implications for conservation, we chose to examine the mammals of Polylepis woodlands within one high Andean valley. Small mammals play a key role in community dynamics because they consume seeds and are also important in their dispersal [21,22]. We compared the structure of the communities of non-volant small mammals in an intact, mature homogenous Polylepis incana (Rosaceae) woodland with a nearby, disturbed mid-successional Polylepis woodland to determine the effects of habitat degradation.…”