Foxes were removed from several islands and the goose population recovered to
its former densities, helped by some reintroductions (Springer et al. 1978; Byrd
et al. 1994).
The restoration of islands that can be used as refuges for endangered birds is
a well-proven technique and is successful because harmful predators can be
completely eradicated. On mainland areas, all that is usually possible is localized
control or the fencing out of some problem species. Fencing technology is
becoming increasingly sophisticated and the New Zealand “super fence” keeps
out all mammals including rats and mice. The Karori Wildlife Sanctuary,
Wellington has been surrounded by 8.6 km of fencing and threatened species
that may formerly have occurred there such as the Little Spotted Kiwi Apteryx
oweniiare being re-introduced within the fenced area (Bell and Merton 2002;
J. Mallam personal communication).
Predator control raises issues of ethics and welfare and should always be
carried out to the highest standards. Although the science of predator control
and eradication is well established, a great deal of experience is usually needed
before trappers become efficient. Good trappers approach the subject with
meticulous detail and a keen intuition and consequently may catch many more
animals than a novice.
12.4 Intensive management of focal pairs
12.4.1Close guarding and monitoring of nests
The main purposes of close guarding are to:
- Monitor the progress of the focal pairs and to build a body of knowledge on
the biology and behavior of the species. - Assess the suitability of the watched pair for possible clutch and brood
manipulations. - Monitor the results and progress of any manipulations.
- React to problems that threaten the pair or their nesting attempt (e.g. nest-site
enhancement, supplemental feeding, control of parasites, predators, and
competitors). - Rescue clutches and broods from failing nesting attempts, or if necessary
hand-feed and re-hydrate ailing chicks.
In the most critically endangered species 24-h guarding and monitoring has
sometimes been undertaken. Some are monitored by video systems (Kakapo
project) or by teams of volunteers (California Condor, Pink Pigeon, Echo
Parakeet projects), but there must be clear guidelines on procedures if the nest
280 |Conservation management of endangered birds