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Providing evidence to improve practice

Individual study: Habitat management influences overwinter survival of mule deer fawns in Colorado

Published source details

Bergman E.J., Bishop C.J., Freddy D.J., White G.C. & Doherty P.F. (2014) Habitat management influences overwinter survival of mule deer fawns in Colorado. The Journal of Wildlife Management, 78, 448-455


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

Restore or create grassland Terrestrial Mammal Conservation

A replicated, site comparison study in 2005–2008 of a pine-juniper forest in Colorado, USA (Bergman et al. 2014) found that seeding with grassland species as part of a suite of actions including mechanical disturbance and herbicide application (referred to as advanced management) increased overwinter survival of mule deer Odocoileus hemionus fawns. Average overwinter survival was highest under advanced management (77%), intermediate under mechanical disturbance and reseeding but without follow-up actions (69%) and lowest with no habitat management (67%). Mechanical management, commencing in 1998–2004, involved removing and mulching trees to create open areas. These were reseeded with grasses and other flowering plants. Follow-up actions in advanced management plots, two to four years later, involved controlling weeds with herbicide and further seeding with deer browse species. Management actions were not carried out individually, so their relative effects cannot be determined. Fawns were radio-collared on eight study plots; two advanced management plots, four mechanical management plots and two unmanaged plots. Survival was assessed by monitoring fawns from capture (1 December to 1 January) until 15 June, in winters of 2004–2005 to 2007–2008, three to six years after mechanical treatments.

(Summarised by Nick Littlewood)

Remove vegetation using herbicides Terrestrial Mammal Conservation

A replicated, site comparison study in 2005–2008 of a pine-juniper forest in Colorado, USA (Bergman et al. 2014) found that herbicide application (combined with seeding and preceded by mechanical disturbance and initial seeding – referred to as advanced management) increased overwinter survival of mule deer Odocoileus hemionus fawns. Management actions were not carried out individually, so their relative effects cannot be determined. Average overwinter survival was highest under advanced management (77%), intermediate under mechanical disturbance and seeding without follow-up actions (69%) and lowest with no habitat management (67%). Mechanical management, commencing in 1998–2004, involved removing and mulching trees to create open areas. These were seeded with grasses and forbs. In advanced management plots, follow-up actions, two to four years later, involved controlling weeds with herbicide and further seeding with deer browse species. Fawns were radio-collared on eight study plots; two advanced management plots, four mechanical management plots and two unmanaged plots. Survival was assessed by monitoring fawns from capture (1 December to 1 January) until 15 June, in winters of 2004–2005 through to 2007–2008, three to six years after mechanical treatments.

(Summarised by Nick Littlewood)

Remove vegetation by hand/machine Terrestrial Mammal Conservation

A replicated, site comparison study in 2005–2008 of a pine-juniper forest in Colorado, USA (Bergman et al. 2014) found that mechanical disturbance of vegetation (combined with reseeding, follow-up herbicide application and further seeding – referred to as advanced management) increased overwinter survival of mule deer Odocoileus hemionus fawns. Management actions were not carried out individually, so their relative effects cannot be determined. Average overwinter survival was highest under advanced management (77%), intermediate under mechanical disturbance and seeding without follow-up actions (69%) and lowest with no habitat management (67%). Mechanical management, commencing in 1998–2004, involved removing and mulching trees to create open areas. These were seeded with grasses and flowering plants. Follow-up actions in advanced management plots, two to four years later, involved controlling weeds with herbicide and further seeding with deer browse species. Fawns were radio-collared on eight study plots; two advanced management plots, four mechanical management plots and two unmanaged plots. Survival was assessed by monitoring fawns from capture (1 December to 1 January) until 15 June, in winters of 2004–2005 through to 2007–2008, three to six years after mechanical treatments.

(Summarised by Nick Littlewood)