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Providing evidence to improve practice

Individual study: Preventing mule deer drownings in the Mohawk Canal, Arizona

Published source details

Rautenstrauch K.R. & Krausman P.R. (1989) Preventing mule deer drownings in the Mohawk Canal, Arizona. Wildlife Society Bulletin, 17, 280-286

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

Provide mammals with escape routes from canals Terrestrial Mammal Conservation

A study in 1982–1985 in a canal between farmland and desert in Arizona, USA (Rautenstrauch & Krausman 1989) found that ramps and ladders reduced mule deer Odocoileus emionus drownings. Of at least 282 times that deer fell into the canal over a 40-month period, three deer drowned, 116 escaped via steps, 79 via ramps and eight via metal ladders. A further 50 escaped without using structures and 10 were pulled out alive. Exit points of 16 deer were not determined. Over two previous years, before escape routes were improved, 18 deer drowned on the same canal section. A 15-km-long canal section, 5.5–10 m wide was studied. There were six dams, five with existing escape stairs. In 1980–1981, three escape ramps (3 m wide, at 25° to the direction of water flow with a 25% slope) were added. There was also one 1.3-m-wide iron ladder and seven reinforcement-bar ladders (date of installation not stated). Wire cables (3 cm diameter) across the water surface, directed trapped deer toward each escape structure. Deer were monitored and reported by canal workers and by monitoring tracks at 1–3 day intervals in June 1982 to September 1985 (total 478 visits). Drownings in 1979–1980 were logged by canal staff.

(Summarised by Ricardo Rocha)