Biological control of vertebrates - a review and an assessment of prospects for Malaysia

Wood B.J., . Biological control of vertebrates - a review and an assessment of prospects for Malaysia. pp. 67-79. ISSN 0127-6883

Manipulation of predators and parasites against vertebrate pests had not generally been effective. The literature recorded only one clear cut success the myxomatosis disease of rabbits. Among possible reasons were that natural enemies were insufficiently density dependent to control populations that vertebrates had complex and adaptable physiology that they could rapidly reproduce to meet continuous losses or restore numbers after decimation and relatively small numbers (compared with insects for example) could still do serious harm. Predators might only remove surplus animals above an environment support level but sometimes there was evidence that they established lower equilibrium levels. Most predators had a non-specific diet and could have severe side-effects in new localities especially if there were no effective native predators -e.g. island ecosystems. The few recorded importations involved small carnivores against introduced rats and rabbits e.g. the Indian mongoose to Caribbean and Pacific Islands and mustelids to Australia and New Zealand. All attacked native animals and poultry but had little effect on the target species. Predator numbers appeared more affected by prey than vice versa e.g. if rats were controlled by baiting in Malaysian oil palms snakes tend to disappear. Generalist predators with alternative prey sometimes appeared capable of restraining increase of one particular prey species. It might be possible to buffer predator numbers by supporting them or altering the environment e.g. cats on farms by feeding or owls in oil palms by giving nesting sites. Parasites (diseases) might carry risks for non-target species including man. Naturally-occurring forms might flare up when vertebrate host populations built up. Evidence of their effect was usually equivocal although myxomatosis had greatly reduced rabbit numbers. Baits employing acute pathogens had success against rats. In Malaysia the coccidian Sarcocystissingaporensis which required phythons as an intermediate host was lethal to rats. Also rats in the field might be heavily infected by helminths. However no dramatic achievement in biological control of vertebrates could be expected but possibilities for rats Malaysia's most serious vertebrate pests were worth pursuing especially in the context of recent reports of warfarin resistance. There was a need of more concerted effort which could be part of a greater national focus biologica

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Abstract

Manipulation of predators and parasites against vertebrate pests had not generally been effective. The literature recorded only one clear cut success the myxomatosis disease of rabbits. Among possible reasons were that natural enemies were insufficiently density dependent to control populations that vertebrates had complex and adaptable physiology that they could rapidly reproduce to meet continuous losses or restore numbers after decimation and relatively small numbers (compared with insects for example) could still do serious harm. Predators might only remove surplus animals above an environment support level but sometimes there was evidence that they established lower equilibrium levels. Most predators had a non-specific diet and could have severe side-effects in new localities especially if there were no effective native predators -e.g. island ecosystems. The few recorded importations involved small carnivores against introduced rats and rabbits e.g. the Indian mongoose to Caribbean and Pacific Islands and mustelids to Australia and New Zealand. All attacked native animals and poultry but had little effect on the target species. Predator numbers appeared more affected by prey than vice versa e.g. if rats were controlled by baiting in Malaysian oil palms snakes tend to disappear. Generalist predators with alternative prey sometimes appeared capable of restraining increase of one particular prey species. It might be possible to buffer predator numbers by supporting them or altering the environment e.g. cats on farms by feeding or owls in oil palms by giving nesting sites. Parasites (diseases) might carry risks for non-target species including man. Naturally-occurring forms might flare up when vertebrate host populations built up. Evidence of their effect was usually equivocal although myxomatosis had greatly reduced rabbit numbers. Baits employing acute pathogens had success against rats. In Malaysia the coccidian Sarcocystissingaporensis which required phythons as an intermediate host was lethal to rats. Also rats in the field might be heavily infected by helminths. However no dramatic achievement in biological control of vertebrates could be expected but possibilities for rats Malaysia's most serious vertebrate pests were worth pursuing especially in the context of recent reports of warfarin resistance. There was a need of more concerted effort which could be part of a greater national focus biologica

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Item Type:	Article
Additional Information:	67 ref. Summaries (En Malay)
AGROVOC Term:	MAMIFEROS NOCIVOS
AGROVOC Term:	CONTROL BIOLOGICO
AGROVOC Term:	DEPREDADORES
AGROVOC Term:	MALASIA/ PARASITOS
Depositing User:	Ms. Norfaezah Khomsan
Last Modified:	24 Apr 2025 05:53
URI:	http://webagris.upm.edu.my/id/eprint/18515

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