Use of highway culverts by the water opossum (Chironectes minimus) in southeastern Brazil

Paula Ribeiro Prist,Guilherme S T Garbino,Thais Pagotto,Fernanda Delborgo Abra,Osnir Ormon Giacon

doi:10.1590/1676-0611-bn-2020-1058

Abstract

Abstract The water opossum (Chironectes minimus) is a semi-aquatic mammal that is infrequently sampled in Atlantic rainforest areas in Brazil. Here we report on new records of C. minimus in the state of São Paulo, southeastern Brazil, and comment on its behavior and ecology. We placed nine camera traps in culverts and cattle boxes under a highway, between 2017 and 2019. From a total of 6,750 camera-trap-days, we obtained 16 records of C. minimus (0.24 records/100 camera-trap-days) in two cameras placed in culverts over streams. Most of the records were made between May and August, in the dry season and in the first six hours after sunset. The new records are from a highly degraded area with some riparian forests. The records lie approximately 30 km away from the nearest protected area where the species is known to occur. We suggest that C. minimus has some tolerance to degraded habitats, as long as the water bodies and riparian forests are minimally preserved. The new records presented here also fill a distribution gap in western São Paulo state.

Highlights

Our understanding of the ecology (Galliez et al 2009, Fernandez et al 2015) and distribution (Ardente et al 2013, Brandão et al 2015) of the water opossum (Chironectes minimus) has substantially improved in recent years
Vehicle collisions are rare, a single roadkilled C. minimus was recorded among 444 roadkilled mammals in southern Brazil (Coelho et al 2008), and in São Paulo state one C. minimus was found among 184 roadkilled mammals (Prada 2004)
Other animals observed in the videos that captured C. minimus were capybaras (Hydrochoerus hydrochaeris), and unidentified bats and frogs, but they did not interact with the water opossum

Summary

Introduction

Our understanding of the ecology (Galliez et al 2009, Fernandez et al 2015) and distribution (Ardente et al 2013, Brandão et al 2015) of the water opossum (Chironectes minimus) has substantially improved in recent years. Most of the information on the ecology of C. minimus comes from studies carried out in Rio de Janeiro, southeastern Brazil, which have shed light on the home length, population density, use of shelters, and activity pattern of the species (Galliez et al 2009, Leite et al 2013, Fernandez et al 2015, Leite et al 2016) These and other reports show that C. minimus uses water bodies with sandy or stony substrates, fast-flowing water, and with well-preserved riparian forests (Palmeirim et al 2014, Voss et al 2001, Bressiani & Graipel 2008). Vehicle collisions are rare, a single roadkilled C. minimus was recorded among 444 roadkilled mammals in southern Brazil (Coelho et al 2008), and in São Paulo state one C. minimus was found among 184 roadkilled mammals (Prada 2004)

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Results

Conclusion