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Providing evidence to improve practice

Individual study: Crossing structures reconnect federally endangered flying squirrel populations divided for 20 years by road barrier

Published source details

Kelly C.A., Diggins C.A. & Lawrence A.J. (2013) Crossing structures reconnect federally endangered flying squirrel populations divided for 20 years by road barrier. Wildlife Society Bulletin, 37, 375-379


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Install pole crossings for gliders/flying squirrels Terrestrial Mammal Conservation

A replicated study in 2008–2010 at three sites along a road through forest in North Carolina, USA (Kelly et al. 2013) found that crossing poles were used by Carolina northern flying squirrels Glaucomys sabrinus coloratus to cross the road. All three radio-tagged flying squirrels crossed the road with at least one using a crossing pole. Out of 25 videos of flying squirrels at crossing poles, 14 (56%) showed crossing attempts (landing on the opposite pole was not confirmed). In June 2008, six wooden poles (32 cm diameter) were set in three pairs on opposite sides of a two-lane road. Poles, 15 m apart, were buried 2.4 m into the ground and extended 14.3 m above ground. Each pole was fitted with a 3-m-long, 10 × 19-cm horizontal wooden launch beam at the top. In March 2009, three flying squirrels were fitted with radio-transmitters and released onto a crossing pole on the opposite side of the road from their capture location. They were tracked at least monthly between March–June 2009. Infrared motion detection cameras were used at each pole between March 2009 and June 2010 to detected crossings.

(Summarised by Ricardo Rocha)

Provide artificial dens or nest boxes on trees Terrestrial Mammal Conservation

A study in 2008–2011 in a forest area in North Carolina, USA (Kelly et al. 2013) found that nest boxes were used by northern flying squirrels Glaucomys sabrinus. Sixteen northern flying squirrels were caught at nest boxes. The study was conducted in a forest area dominated by eastern hemlock Tsuga Canadensis. The number of nest boxes used was not detailed. Nest boxes measured 30 × 18 × 15 cm, had a 5 × 5-cm entrance, and were attached 3.6 m up the trunks of trees using nails and wire. They were monitored in winters of 2008 to 2011 and in spring 2009. Captured flying squirrels were individually tagged.

(Summarised by Ricardo Rocha)