Modelling Deer Population Dynamics Forest Research Is deer

Modelling Deer Population Dynamics Forest Research

Is deer management cost-effective? Other herbivores, weather /climate, site conditions. External deer density Immigratio n /emigration Resource Inputs /costs Timber objectives Mortality Deer population density (all species) Culling rate /strategy Tree /habitat condition Biodiversity value Browsing /grazing/ dunging Weather /climate Birth rate /mortality Habitat types /pattern Timber value Economic yield Quality of life yield Biodiversity objectives Tree protection /replacement Resource Inputs /costs Forest Research

Inputs 1 1. Enter recruitment and survival rates Forest Research

Recruitment rate : information sources • Cull pregnancy rates • Cull lactation rates • Cull calf: hind ratios • Calf: hind observations • Published information Forest Research

Survival rates: information sources • Published information Forest Research

Inputs 2 2. Enter initial numbers of deer in each age class (in summer before the cull) Forest Research

Initial population size: information sources • Dung density assessments • Visual /Infra red imager counts • Cohort analysis Forest Research

Initial sex and age structure: information sources • Observations of sex ratio • Cull sex and age structure • Published information Forest Research

Inputs 3 3. Enter actual or proposed culls Forest Research

Model output 19% stag and hind cull 25% stag and hind cull 40% stag, 60% hind cull 20% stag, 80% hind cull 50% stag and hind cull 40% stag, 80% hind cull Forest Research