Restoration of threatened species populations: tuatara rehabilitations and re-introductions
type: CreativeWork
description: The role of scientific theory in encouraging greater efficiency and accountability for the restoration of threatened species populations is assessed for an endemic New Zealand reptile, the tuatara Sphenodon spp. The value of examining assumptions underlying concepts such as 'habitat requirements' theory and incorporating scientific principles into species recovery are discussed and perceived habitat needs for tuatara tested through experimental application. Species restoration in New Zealand, especially re-introductions, are typically undertaken as one-off, non-replicated, management exercises (trials). The lack of comparative controls for trials means that the reason for success or failure of management actions cannot be identified accurately and therefore, cannot be used to improve the probability of success for subsequent re-introductions. Trials also reinforce conservative re-introductions of species to habitats in which species are known to survive, because the risk of failure is inherently lower than re-introductions to dissimilar habitats where habitat suitability is unknown. An alternative approach is to plan management actions as experiments. Testing the full range of perceived habitat needs of species as experimental comparisons identifies the relative importance of tested factors (e.g. predators, refuges) for species recovery and identifies new management strategies (e.g. reduced level of predator control). Constructing testable hypotheses for the environmental factors thought to affect the success of restoration projects for tuatara identifies (among others) three factors: 1. absence of the introduced rat, the kiore (Rattus exulans) 2. presence of seabird colonies 3. presence of open canopy forest The threat posed by kiore to established tuatara populations was investigated by determining the existence and degree of food competition before and after an eradication program for kiore on offshore islands. Kiore successfully out-competed tuatara for favoured…
abstract: The role of scientific theory in encouraging greater efficiency and accountability for the restoration of threatened species populations is assessed for an endemic New Zealand reptile, the tuatara Sphenodon spp. The value of examining assumptions underlying concepts such as 'habitat requirements' theory and incorporating scientific principles into species recovery are discussed and perceived habitat needs for tuatara tested through experimental application. Species restoration in New Zealand, especially re-introductions, are typically undertaken as one-off, non-replicated, management exercises (trials). The lack of comparative controls for trials means that the reason for success or failure of management actions cannot be identified accurately and therefore, cannot be used to improve the probability of success for subsequent re-introductions. Trials also reinforce conservative re-introductions of species to habitats in which species are known to survive, because the risk of failure is inherently lower than re-introductions to dissimilar habitats where habitat suitability is unknown. An alternative approach is to plan management actions as experiments. Testing the full range of perceived habitat needs of species as experimental comparisons identifies the relative importance of tested factors (e.g. predators, refuges) for species recovery and identifies new management strategies (e.g. reduced level of predator control). Constructing testable hypotheses for the environmental factors thought to affect the success of restoration projects for tuatara identifies (among others) three factors: 1. absence of the introduced rat, the kiore (Rattus exulans) 2. presence of seabird colonies 3. presence of open canopy forest The threat posed by kiore to established tuatara populations was investigated by determining the existence and degree of food competition before and after an eradication program for kiore on offshore islands. Kiore successfully out-competed tuatara for favoured…
author: Ussher, Graham
language: en
keywords: herpatology
license: https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm
date published: 1999
date modified: 2026-07-24T01:06:48Z
provider: University of Auckland
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: ResearchSpace@Auckland

PropertyValue
property ID: Handle
value: https://hdl.handle.net/2292/1939