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Contact rate calculation for wild deer

Source: R/calc_contact_rate.R
calc_contact_rate.Rd

calc_contact_rate() uses proximity rate model developed by Habib et al. (2011) to estimate proximity rates for deer in wild settings, conditional on density and habitat availability. This function can also be used for captive settings with conditions that result in identical deer-deer proximity rates. The user can alter proximity rates with the inclusion of attractants on a landscape.

Usage

calc_contact_rate(
  kappa = NULL,
  N_w = NULL,
  q = NULL,
  A_w = NULL,
  rho_attractant = NULL,
  nsamples = NULL,
  seed = NULL,
  type_contact = NULL
)

Arguments

kappa

value for contact scaling constant (influences slope of density- contact relationship; reported in Habib et al. 2011)

N_w

total population size of deer. Defaults is a random draw from a Poisson distribution with mean = 1000.

q

value for concavity scaling constant (0-1, with 0 equating to density dependence and 1 equating to frequency dependence; reported in Habib et al. 2011)

A_w

area inhabited by N, in square kilometers. Default set to 100 square kilometers to match Habib et al.'s (2011) approach.

rho_attractant

proportional change for attractants present in simulated conditions (optional). Default set to 1

nsamples

number of values to be returned. Default is 1, but will return a vector if > 2

seed

if specified, sets a seed for the function

type_contact

option between "low", "medium", and "high" based on parameters from Habib et al. 2011 for particular values of wooded habitat available to the deer population in question. "low" contact fixes kappa to 16.37 and q to 0.53, mimicking proximity rates in areas with 53% wooded habitat. "med" contact fixes kappa to 11.35 and q to 0.34, mimicking proximity rates in areas with 26% wooded habitat. "high" contact fixes kappa to 15.58 and q to 0.32, mimicking proximity rates in areas with 12% wooded habitat. If set to "manual", manual input of kappa and q are needed. All values from Habib et al. (2011) are available in the contact_rate_params dataset.

Value

returns a number or numeric vector if nsamples > 1

Examples

 if (FALSE) {
calc_contact_rate(type_contact = "low")

calc_contact_rate(rho_attractant = 1,
kappa = 16.37,
N_w = 1000,
q = 0.53,
A_w = 100,
type_contact = "manual")

calc_contact_rate(rho_attractant = c(1,1),
kappa = c(16.37, 16.37),
N_w = rpois(2, 1000),
q = c(0.53, 0.53),
A_w = c(100, 100),
type_contact = "manual")}