The state government of Angaur Island describes macaques as “serious pests”, and in June 2001 introduced an eradication programme. Over 500 macaques were eliminated. The local community hunt macaques, with some success in controlling the population. They are often caught and sold as pets to other islands in Palau.
The Hong Kong government began a trial population control programme in 2002, due to concerns about the human health issues posed by the macaques. They used Porcine Zona Pellucida (PZP), an immunovaccine which causes infertility in females. It is not clear whether PZP is effective in the medium to long term, and field observations of the macaques were to continue for two years to determine efficacy.
The eliminaton of macaques from forest environments is considered to be the second highest priority after pigs and deer. Problem populatons have been trapped from conservation forests and agricultural areas, but has met with little success as the macaques became trap shy. Lethal control is generally not considered a management option for socio-religious reasons.
Preventative management: Plantations of Japanese red cedar (Cryptomeria japonica) appear to provide protection to some species of native birds from the predating and scavenging of macaques. Studies of the nesting success of the critically endangered Mauritian fody (Foudia rubra) linked a higher nest success rate with nests built in cedar plantations rather than native forest (46% in comparison with 6%). It was observed that the last remaining (wild) pink pigeons nested only in one of the four mainland sites they were released in, which also happened to be a cedar plantation (Safford, 1997a, Bright and Carter, 1999). For a discussion about the benefits of establishing exotic plantations to protect Mauritian threatened birds from mammalian predators please read:
Safford and Jones. 1998. Strategies for Land-Bird Conservation on Mauritius
In a study carried out in the Black River Gorges National Park by Carter and Bright (2002) experimental (relative) rates of nest egg predation by macaques and rats were correlated with vegetation type (for both the breeding and non-breeding seasons of the Mauritian fody). Predation by macaques was found to be decreased in cedar dominated sites during both seasons. Predation by rats was found to be increased in cedar dominated sites during both seasons (possibly due to a lack of competitive pressure with macacques, although this was not mentioned in the study). It is hypothesised that macaques may avoid cedar plantations due to the lower diversity of food resources, rats being undeterred by this. Total predation was lowest in weeded forest plots outside of the breeding season and lowest in cedar plantations during the breeding season. Some weeded plots contained rat baits, and all exhibited a lower level of fruits produced by exotic species such as Psidium spp. This suggests weeding may reduce the suitability of native forest for omnivorous predator species.
The authors suggest that areas appropriate for the establishment of new cedar plantations (to increase the breeding success of Mauritian fodies) should be: (i) areas supporting only non-native (not native) vegetation; suitable sites include areas currently populated by pine and eucalyptus (Eucalyptus robusta), (ii) areas in the National Park and part of the range of the Mauritius fody, (iii) greater than 500 meters from highly degraded forest areas (this being the radius of a macaque troops range), and (iv) less than 320 meters from native forest (this being the diameter of the circular territory of the Mauritian fody, which feeds on native vegetation although it might nest in non-native vegetation) (Carter and Bright, 2002). To view the proposed locations for new cedar plantations in the Black River Gorges National Park please see:
Bright and Carter, 1999. Exotic Vegetation as a Refuge From Predation for Endangered Mauritian Birds.
Expanding the range of cedar plantations may have the unwanted effect of decreasing competitive pressures imposed on rats from macacques (by increasing the amount of habitat favourable to rats). The possible increase rat numbers may lead greater rat predation in cedar dominated sites and a decrease in breeding success (thereby negating the initial positive effect). This highlights the need for modelling of the prey-predator population dynamics involved.
Papua (Irian Jaya)
Any management programme would require support from all stakeholders – landowners, government and the local community. Policy makers have previously considered macaques to be "Indonesian" and have put nothing in place manage them. However, local communities are highly aware of their natural resources and native species and consider the species to be alien.
No attempt at management has been made to date but the Papua Regional Government is very supportive of macaque management and of the Indo-Pacific Conservation Alliance. A programme of eradication is planned for 2005. It will also incorporate a review of current legislation and infrastructure set up to prevent the import of exotics into Papua and attempt to lobbying for an increased capacity in the quarantine department. Any people involved in handling macaques during any such programme would need to take special precautions to prevent the transmission of disease (such as the potentially fatal B-virus) through bites and scratches.
There are three possible management options for reducing the impact of macaques in Papua: containment (by preventative management), control (by biological control) and eradication (by physical control):
Preventative management: Containment has the potential to reduce the population growth and expansion rate of macaques. At present the Indonesian Department for Animal Quarantine only targets macaques due to their potential to spread rabies but they are limited in funding and capacity and their measures are not always successful. New legislation is needed to prevent alien species in general from being introduced to Papua (including the prevention of the import and release of macaques). The risk of pets escaping and forming new populations is significant (as many people import the animals to keep or sell as pets).
Biological control: The use of Porcine Zona Pellucida (PZP) immunocontraceptive vaccine, or surgical sterilisation are possibilities.
Physical control: Eradication could be an option as macaque numbers are low and the population is confined to a relatively small area. This could be achieved by hunting, trapping or poisoning. Some locals currently hunt macaques, possibly reducing their population growth. Trials have shown that baiting is valuable in conditioning macaques to a human presence, and trapping is best carried out between April and July (when natural food resources are limited). A high capture rate was obtained with the use of high quality traps. Macaques spend a significant amount of time in particular areas on the ground, and this can be taken advantage of when developing trapping regimes.
1. Bertram, B. and Ginsberg, J. 1994. Monkeys in Mauritius: Potential for Humane Control (Confidential report by the Zoological Society of London commissioned by the RSPCA): 25.
摘要： Confidential report summarising the problems posed by crab-eating macaques on Mauritius and the feasibility of humane population control.
3. Bright, P. and Carter, S. 1999. Exotic Vegetation as a Refuge From Predation for Endangered Mauritian Birds. British Ecological Society.
6. deRuiter, J.R. 1992. Capturing Wild Long-tailed Macaques (Macaca fascicularis), Folia Primatology 59: 89 - 104.
摘要： Effective techniques for capturing macaques
7. IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4.
摘要： The IUCN Red List of Threatened Species provides taxonomic, conservation status and distribution information on taxa that have been globally evaluated using the IUCN Red List Categories and Criteria. This system is designed to determine the relative risk of extinction, and the main purpose of the IUCN Red List is to catalogue and highlight those taxa that are facing a higher risk of global extinction (i.e. those listed as Critically Endangered, Endangered and Vulnerable). The IUCN Red List also includes information on taxa that are categorized as Extinct or Extinct in the Wild; on taxa that cannot be evaluated because of insufficient information (i.e. are Data Deficient); and on taxa that are either close to meeting the threatened thresholds or that would be threatened were it not for an ongoing taxon-specific conservation programme (i.e. are Near Threatened).
Available from: http://www.iucnredlist.org/ [Accessed 25 May 2011]