You are proposing to sustainably harvest a population of wallabies in a bushland. Through a mark recapture study over two years you have estimated population size and determined a static life table. This data has been used to established a long-term harvest quota in the bushland. What are the problems with setting a harvest quota based on the results of your study.. Ecology

Problems with mark and recapture:

  • Not all animals may have an equal chance of being caught, may exclude subsets of animals from your estimate
  • Marking animals may affect their subsequent survival or Catchability
  • Animals may lose their marks between two sampling periods
  • Mortality and emigration rates of marked and unmarked animals may not be equal

All of these problems may lead to an estimate which does not truly represent the true nature of the system in question

Additional problems:

  • 2 years is not long enough to determine a long term harvest quota.
  • The long term population may be affected by such factors which you have not witnessed such as:

o Drought and/or flood (perhaps caused by ENSO)

o Disturbance

o Possible population cycling in the long term, the animal may thrive in El Nino years (which may have been when you sampled)