Suchergebnisse

Context
The value of animal reintroduction as a conservation tool is debated. This is largely because the limited quantity of research that has been conducted on animal reintroductions has shown varying degrees of success in establishing new populations. The reasons why some reintroductions are successful, whereas others are not, are often not clear.

Aims
The present research aims to determine whether reptile reintroduction into restored mine pits is a potential management technique for managing and conserving reptile populations within a mined landscape.

Methods
Twelve Napoleon's skinks were trapped then fitted with 0.9-g transmitters. Half were reintroduced into 5-year-old restored mine pits and the other half into unmined forest. Bodyweights, movement patterns and macro-habitat selection were recorded weekly during November and then monthly until March.

Key results
Skinks reintroduced into restored sites quickly moved into unmined forest. Both groups of skinks moved large distances, but those reintroduced into restored sites travelled further than did control skinks and took longer to reduce their distances travelled, showing possible stress as a result of release into unsuitable habitat. Eventually, almost all skinks found suitable habitat in unmined forest and settled into these areas while continuing to gain weight.

Conclusions
Reintroduction was an ineffective technique for facilitating colonisation of restored minesites by Napoleon's skink. Lack of suitable micro-habitats within restoration areas, such as ground logs and coarse, woody debris piles, is likely limiting the use of these areas by Napoleon's skinks and is likely to be the cause of their failure to remain or settle in restored sites after reintroduction.

Implications
Determining the habitat requirements of skinks and replicating this in restoration sites would seem the more appropriate management option than is reintroduction, and this may be the case for other reptiles and habitat specialists.

Context
Provision of key habitat resources is essential for effectively managing species that have specific ecological requirements and occur in production landscapes. Threatened black cockatoos in the jarrah (Eucalyptus marginata) forest of Western Australia have a wide range, so their conservation requires support from all land tenures, not just reserves. Mining in the jarrah forest temporarily removes cockatoo feeding habitat, so it is important to understand how cockatoos exploit revegetated areas for food resources.

Aims
We aimed to determine whether there were successional patterns in cockatoo feeding activity in revegetation aged from 4 to 23 years at three mine sites in the jarrah forest in south-western Australia.

Methods
We surveyed 232 plots in revegetation to document (1) structural and floristic variation in vegetation across mine sites and revegetation ages, (2) differences in cockatoo feeding activity across mine sites and revegetation ages on the basis of feeding residues and (3) any edge effect reflecting preferential use of vegetation at the interior or exterior of mine pits. We also documented the frequency of occurrence of cockatoo food plants and feeding residues in 480 plots in unmined forest to compare with revegetated areas.

Key results
Marri (Corymbia calophylla) and jarrah were commonly consumed in unmined forest and Banksia and Hakea species were also fed on to a lesser extent. Revegetated mine pits provided food within 4 years and continued to do so up until the oldest plots studied (23 years). The relative importance of food plants shifted from proteaceous species in young revegetation to myrtaceous species in intermediate to older revegetation. However, extent of feeding on myrtaceous species in older revegetation did not equate to feeding rates in unmined forest, with lower frequencies recorded in revegetation.

Conclusions
Black cockatoos fed in revegetation at all three mine sites, despite variations in vegetation age, structure and floristics. Feeding on proteaceous and myrtaceous food plants occurred within 4 and 7 years of revegetation being established, respectively, indicating that some food resources are restored quickly after mining disturbance of the jarrah forest.

Implications
Our results emphasise the importance of monitoring fauna recolonisation over appropriate time scales, to understand how successional processes in revegetation influence fauna population persistence in production landscapes.