Monitoring small and arboreal mammals by camera traps: effectiveness and applications


Camera trapping has been widely applied to studies of medium to large terrestrial mammals, but its application to small arboreal mammals has hardly been tested. We employed camera trapping and other conventional monitoring methods during a mammal survey in a Site of Community Importance located within the Adda North Regional Park (Lombardy, Italy). Camera trapping was particularly successful for monitoring arboreal mammals, allowing the first detection of presence of the invasive grey squirrel (Sciurus carolinensis) in an area occupied by indigenous red squirrels (Sciurus vulgaris) and the collection of a large amount of data on squirrels and common dormice (Muscardinus avellanarius). When triggered, cameras were set to record short video clips (10 to 40 s). More than 400 events were recorded and analysed, mainly from the autumn and winter months. The daily activity pattern of both species displayed a trend from two to three activity peaks in summer to a unimodal pattern in winter, with the peaks of the two species temporally separated. Camera trapping could be a useful method also when applied to monitoring small mammals, particularly endangered arboreal or invasive alien species. For instance, the monitoring of the spread of S. carolinensis is particularly important, where the early detection of new population can be crucial for the conservation of indigenous European species. Camera trapping can be an effective addition to traditional survey methods. It provides a simple non-invasive technique for collecting a large amount of data per device with limited human effort.

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Fieldwork was funded by Adda North Regional Park for the Management Plan of SCI IT2050011. Partial results have been presented as poster to the Problematic Wildlife II International Congress, Genazzano, Italy, February 2011. We are grateful to Dr. Sergio Saladini (Director) and Dr. Giuliana Defilippis (Resp. for Natural Resources) of the Adda North Regional Park and Fabio Cologni and all the WWF volunteers of the Oasi Le Foppe of Trezzo sull’Adda (MI). We also wish to thank two anonymous reviewers for their most valuable suggestions and advice.

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Correspondence to Carlo M. Biancardi.

Additional information

Communicated by: Karol Zub

Electronic supplementary material

Below is the link to the electronic supplementary material.

Squirrels shot in three different seasons. (MPG 9822 kb)

Interactions of grey and red squirrels with magpies. (MPG 10068 kb)

Red and grey squirrels shot in different activities: collecting food, foraging, feeding, playing with a hair tube, bark stripping (infrared because of the dark underwood), travelling. (MPG 10766 kb)

Online Resource 1

Red squirrel shot while feeding on a baited tree branch. Grey squirrel shot in two different sites. (MPG 9372 kb)

Online Resource 2

Squirrels shot in three different seasons. (MPG 9822 kb)

Online Resource 3

Interactions of grey and red squirrels with magpies. (MPG 10068 kb)

Online Resource 4

Red and grey squirrels shot in different activities: collecting food, foraging, feeding, playing with a hair tube, bark stripping (infrared because of the dark underwood), travelling. (MPG 10766 kb)

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Di Cerbo, A.R., Biancardi, C.M. Monitoring small and arboreal mammals by camera traps: effectiveness and applications. Acta Theriol 58, 279–283 (2013) doi:10.1007/s13364-012-0122-9

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  • Camera trapping
  • Arboreal mammals
  • Sciurus vulgaris
  • Sciurus carolinensis
  • Alien species
  • Survey methods