Elsevier

Mammalian Biology

Volume 73, Issue 5, 1 September 2008, Pages 337-341
Mammalian Biology

Original Investigation
Diet of some species of Neotropical small mammalsNahrungsanalysen einiger kleiner neotropischer Säugetiere

https://doi.org/10.1016/j.mambio.2007.09.008Get rights and content

Abstract

Dietary analysis was performed to determine the variations in diet of some small neotropical species of mammals collected in seasonal areas of the cerrado (a savannah-like grassland) and semi-deciduous forest. Food items were determined based on the analysis of stomach contents of 126 animals (one didelphid and five sigmodontine rodent species). Most species presented herbivorous-omnivorous habits, with a preference for the vegetative parts of plants. Akodon montensis Thomas (1913) was the most abundant species in the forest area and demonstrated a uniform consumption of animal and vegetal items through the year, and contained 65.7% plant material in its diet. Necromys lasiurus (Lund, 1841) was the most abundant in the cerrado with 72.6% of vegetation in its diet, but showed a high consumption of animal items during the rainy season. Oligoryzomys nigripes (Olfers, 1818) contained 95.1% of plant material, while Oxymycterus delator (Thomas, 1903) consumed 61.6% invertebrates, mainly insects. The didelphid Philander frenatus (Olfers, 1818) consumed invertebrates (47.7%), small vertebrates (7.3%) and plant material (44.9%).

Zusammenfassung

Zum Studium der Variation der Ernährung wurden neotropische Kleinsäuger untersucht, die im Cerrado (Savannen-ähnliche Landschaft) und halb-immergrünen Waldzonen leben. Der Mageninhalt von 126 Tieren (eine Beutelratte und fünf Nagetierarten der Unterfamilie Sigmodontinae) wurde untersucht und identifiziert. Die Arten waren teilweise als Herbivore, teils als Omnivore zu bezeichnen, doch zogen sie vegetative Pflanzenteile als Nahrung vor. Im Wald war Akodon montensis Thomas (1913) die häufigste Art. Sie konsumierte im Laufes des Jahres tierisches und pflanzliches Futter recht gleichmässig, doch machten Pflanzenteile etwa 65,7% der Nahrung aus. Necromys lasiurus (Lund, 1841) war die häufigste Art im Cerrado, mit 72,6% pflanzlichen Bestandteilen der Nahrung. Während der Regenzeit nahm sie aber einen grossen Anteil tierischer Nahrung auf. Die Nahrung von Oligoryzomys nigripes (Olfers, 1818) umfasste 95,1% pflanzliches Material, während die Nahrung von Oxymycterus delator (Thomas, 1903) 61,6% wirbellose Tiere beinhaltete, wobei Insekten überwogen. Die Beutelratte Philander frenatus (Olfers, 1818) konsumierte Wirbellose (47,7%), kleine Wirbeltiere (7,3%) und Pflanzen (44,9%).

Introduction

The eating habits and availability of food resources are essential aspects to understanding populations and communities of mammals, life-history strategies, and ecological roles of animals (DeBlase and Martin 1980; Meserve et al. 1988; Galindo-Leal and Krebs 1998; Martinez et al. 1990). Information about the eating habits of small herbivorous mammals, mainly rodents, is scarce due to their efficient food mastication, which results in small fragments, which are difficult to identify (Hansson 1970). In the Neotropics, some work has been done on food availability as correlated with habitat (Borchert and Hansen 1983; Martinez et al. 1990; Bergallo and Magnusson 1999), demographic population (Fleming 1971; González et al. 1989; Adler and Beatty 1997; Adler 1998; Bergallo and Magnusson 1999) and the reproductive cycle of those animals (Martino and Aguilera 1989; Bilenca et al. 1992; Suarez 1994). In Brazil, the details of the diet of small mammals is limited to some studies (Leite et al. 1996; Santori et al., 1996, Santori et al., 1997; Talamoni et al. 1999). One problem for diet analysis is that the diets of small mammals have often been studied by the analysis of faeces or stomach contents. Analysis of faeces is highly inaccurate because of differential digestion, and stomach contents analysis requires the sacrifice of large numbers of individuals and cannot be used for some species because of conservation considerations (Kronfeld and Dayan 1998). Thus, the animals of this study were also sacrificed for a reproduction study (Couto 2000). The objective of the present work was to determine the diet of some species—Oligoryzomys nigripes (Olfers, 1818), Oryzomys subflavus (Wagner, 1842), Necromys lasiurus (Lund, 1841), Oxymycterus delator (Thomas, 1903), from cerrado (a savannah-like grassland), and Philander frenatus (Olfers, 1818) and Akodon montensis Thomas (1913), from semideciduous forest, both seasonal vegetation types of Brazil, and to contribute to the knowledge of the trophic ecology of Neotropical small mammals.

Section snippets

Study site

The collection of small mammals was carried out monthly from October 1998 to October 1999, in seasonal semideciduous forest and cerrado areas, in the Serra do Rola-Moça State Park (PERM), in the state of Minas Gerais, Brazil (20°03′S, 43°57′W). The Park encompasses nearly 9500 ha, with elevations ranging from 1100 to 1400 m above sea level, and a mosaic of different plant communities include semideciduous forest, cerrado and open areas such as high-altitude fields. The cerrado is Brazil's second

Results

A great consumption of the vegetative parts of plants was observed, except for P. frenatus and O. delator, where analysis indicated a larger proportion of animal origin (55% and 61.6%, respectively). The consumption of small vertebrates was also observed in P. frenatus (Table 1). Indefinable fungi consumption was observed for A. montensis and O. delator. Animal and vegetal diets of A. montensis, the most captured species in the forest, and N. lasiurus, the most captured in the cerrado (Table 1

Discussion

Most rodents showed a herbivorous–omnivorous diet; however, O. delator was considered mainly insectivorous–omnivorous. The consumption of invertebrates in a greater proportion (70%), besides seeds and vegetal tissue, was previously observed in Oxymycterus roberti (Thomas, 1901) (Borchert and Hansen 1983) and Oxymycterus rutilans (Olfers, 1818) (Suarez 1994). In relation to P. frenatus, despite its omnivorous diet, it was observed to have a greater consumption of animal items, including the

Acknowledgements

We thank IBAMA for the licence to capture animals (098/99-NUFAS MG); the Sanitation Company of Minas Gerais (COPASA) for their permission to collect in the APE Mutuca; João A. de Oliveira, from the Museu Nacional do Rio de Janeiro, for the identification of Oxymycterus delator, and to A. Linghorn for English revision. FIP-PUC Minas provided financial support.

References (28)

  • G.H. Adler

    Impacts of resource abundance on populations of a tropical forest rodent

    Ecology

    (1998)
  • G.H. Adler et al.

    Changing reproductive rates in a Neotropical forest rodent, Proechimys semispinosus

    J. Anim. Ecol.

    (1997)
  • H.G. Bergallo et al.

    Effects of climate and food availability on four species in southeastern Brazil

    J. Mammal.

    (1999)
  • D.N. Bilenca et al.

    Food habits of Akodon azarae and Calomys laucha (Cricetidae, Rodentia) in agroecosystems of Central Argentina

    Mammalia

    (1992)
  • M. Borchert et al.

    Effects of flooding and wildfire on valley side wet campo rodents in Central Brazil

    Rev. Brasil. Biol.

    (1983)
  • Couto, D., 2000. Reproduction condition of small mammals of cerrado and forest in a special protection area in the...
  • D. Couto et al.

    Reproductive condition of Akodon montensis Thomas and Bolomys lasiurus (Lund) (Rodentia, Muridae) based on histological and histometric analyses of testes and external characteristics of gonads

    Acta Zool.

    (2005)
  • A.F. DeBlase et al.

    A Manual of Mammalogy With Keys to Families of the World

    (1980)
  • G. Eiten

    Natural Brazilian vegetation types and their causes

    An. Acad. Bras. Ciên.

    (1992)
  • B.A. Ellis et al.

    Dietary habits of the common rodents in an agroecosystem in Argentina

    J. Mammal.

    (1998)
  • Fleming, T.H., 1971. Population Ecology of Three Species of Neotropical Rodents, vol.143. University of Michigan....
  • C. Galindo-Leal et al.

    Effects of food abundance on individuals and populations of the rock mouse (Peromyscus difficilis)

    J. Mammal.

    (1998)
  • L. González et al.

    The effect of seed availability on population density of Oryzomys in Southern Chile

    J. Mammal.

    (1989)
  • L. Hansson

    Methods of morphological diet microanalysis in rodents

    Oikos

    (1970)
  • Cited by (0)

    View full text