9. OPTIONS FOR RECOVERY
Options for recovery presented here include four based on experience from past management techniques (1981-91), i.e. predator control, cross-fostering and egg manipulation, captive rearing and habitat protection and enhancement. Two further options are also considered, establishing a population else...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.81.2123 http://www.doc.govt.nz/upload/documents/science-and-technical/TSRP04a.pdf |
| Summary: | Options for recovery presented here include four based on experience from past management techniques (1981-91), i.e. predator control, cross-fostering and egg manipulation, captive rearing and habitat protection and enhancement. Two further options are also considered, establishing a population elsewhere in Canterbury, based on the few individuals that may nest outside the Mackenzie Basin, or on a predator-free island. 9.1 Do nothing 1 5 If no management occurs it is likely that the black stilt population will decline through failure to produce sufficient young to offset adult mortality. Within 10-20 years it is expected that those genes peculiar to black stilt will be represented only in hybrids with pied stilts and the distinctive form endemic to New Zealand would be effectively lost. 9.2 Manage the population in the wild in the Mackenzie Basin Within this option there are several techniques available as follows: 9.2.1 Control predators by trapping Past predator trapping has involved a combination of large scale coverage of traditional breeding areas beginning prior to nesting, and ring-trapping around located nests. Both methods are labour-intensive and have little if any carry-over benefit from year to year. Yet trapping has produced an increase in survival rates of eggs and chicks overall, breeding success at protected nests increasing to almost 11 % compared to the 1 % of unprotected nests (Pierce, 1987). This breeding success of 11 % is greater than that of unprotected natural pied stilt nests (8.4%). The building and maintenance of predator-proof exclosures is a further option used (see 8.2.). The success of such enclosures relies on birds coming in to breed there, which in turn may depend on the habitats provided within them. No nesting has occurred in the present two exclosures since the 1985/86 season. 9.2.2 Take eggs, artificially incubate and return to wild pairs Currently, added protection from predators is obtained by removing all eggs as soon as they are laid/found and artificially incubating ... |
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