Mule deer behavior at a highway underpass exit


This study is summarised as evidence for the following.

Action Category

Install barrier fencing and underpasses along roads

Action Link
Terrestrial Mammal Conservation
  1. Install barrier fencing and underpasses along roads

    A study in 1974–1979 along a highway in Colorado, USA (Reed 1981; same experimental set-up as Reed et al. 1975) found that an underpass, in an area with roadside fencing, continued to be used by mule deer Odocoileus hemionus 4–9 years after installation Between 1.3 and 5.8 deer/morning (average 2.3) were observed exiting the underpass each year (total 298 deer). Deer behavior suggested that 75% of animals exiting the underpass were reluctant, wary, or frightened. Eleven hesitated just inside the exit and 23 showed wariness or excitability after exiting the underpass. Behavioural responses of deer to the underpass were reported not to have changed substantially over 10 years (1970–1979) of spring-summer use. In 1970, a concrete box underpass (3 m high, 3 m wide, 30 m long) was installed under a 3.2-km section of highway. Entrances were separated from the road by 2.4-m-high barrier fencing. Deer were observed from 130 m away, at 05:00–07:00 h, on 9–30 days (average 16), during each spring/summer migration in 1974–1979. Behavioral responses were likened (but not compared numerically) with those from earlier monitoring that commenced in 1970.

    (Summarised by: Rebecca K. Smith)

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